Download 1 Marsbugs: The Electronic Astrobiology Newsletter, Volume 12

Marsbugs: The Electronic Astrobiology Newsletter
Volume 12, Number 17, 11 May 2005
Editor/Publisher: David J. Thomas, Ph.D., Science Division, Lyon College,
Batesville, Arkansas 72503-2317, USA. [email protected]
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Articles and News
Page 1
ROCK HOUNDS SLEUTH RISE OF EARTH'S
ATMOSPHERE
Carnegie Institution of Washington release
Page 2
HINTS OF HABITABILITY
By Bernard Foing
Page 8
EXPLORATION LIFE AND MEDICAL SCIENCES (ELMS)
COALITION COMES TO LIFE; SUPPORTS SPACE
BIOLOGY ON THE INTERNATIONAL SPACE STATION
American Society for Gravitational and Space Biology release
Mission Reports
Page 3
DID LIFE ARRIVE BEFORE THE SOLAR SYSTEM EVEN
FORMED?
By Jeff Barbour
Page 3
ENVISAT MAKING SHARPEST EVER GLOBAL EARTH
MAP
ESA release
Page 4
A VOLCANIC DINOSAUR DEBATE
By Leslie Mullen
Page 6
PLANETARY PROTECTION: X-RAY SUPER-FLARES AID
FORMATION OF "SOLAR SYSTEMS"
NASA release 05-120
Page 7
"200 MILLION YEAR OLD" TREE PLANTED AT
LONDON PARK
From Agence France-Presse and SpaceDaily
Page 9
CASSINI UPDATES
NASA/JPL releases
Page 11
ROVER TEAM TESTS MARS MOVES ON EARTH
NASA/JPL release 2005-072
Page 12
MARS EXPRESS UPDATES
ESA releases
Page 14
MARS GLOBAL SURVEYOR IMAGES
NASA/JPL/MSSS release
Page 14
MGS FINDS VIKING LANDER 2 AND MARS POLAR
LANDER (MAYBE)
MSSS release
Page 16
MARS ODYSSEY THEMIS IMAGES
NASA/JPL/ASU release
Page 16
EARTH AND MOON THROUGH ROSETTA'S EYES
ESA release
Announcements
Page 7
X-PRIZE ARCHITECT TO SPEAK AT MARS SOCIETY
CONVENTION
Mars Society release
ROCK HOUNDS SLEUTH RISE OF EARTH'S ATMOSPHERE
Carnegie Institution of Washington release
3 May 2005
"CSI-like" techniques, used on minerals, are revealing the steps that led to
evolution of the atmosphere on Earth. President of the Mineralogical Society
of America, Douglas Rumble, III, of the Carnegie Institution's Geophysical
Laboratory, describes the suite of techniques and studies over the last five
years that have led to a growing consensus by the scientific community of
what happened to produce the protective ozone layer and atmosphere on our
planet. His landmark paper on the subject appears in the May/June American
Mineralogist.
"Rocks, fossils, and other natural relics hold clues to ancient environments in
the form of different ratios of isotopes—atomic variants of elements with the
same number of protons but different numbers of neutrons," explained
Rumble. "Seawater, rain water, oxygen, and ozone, for instance, all have
different ratios, or fingerprints, of the oxygen isotopes 16O, 17O, and 18O.
Weathering, ground water, and direct deposition of atmospheric aerosols
change the ratios of the isotopes in a rock revealing a lot about the past
climate."
Rumble's paper describes how geochemists, mineralogists, and petrologists
are studying anomalies of isotopes of oxygen and sulfur to piece together what
happened to our atmosphere from about 3.9 billion years ago, when the crust
of our planet was just forming and there was no oxygen in the atmosphere, to
a primitive oxygenated world 2.3 billion years ago, and then to the present.
The detective work involves a pantheon of scientists who have analyzed
surface minerals from all over the globe, used rockets and balloons to sample
the stratosphere, collected and studied ice cores from Antarctica, conducted
lab experiments, and run mathematical models. The synthesis from the
different fields and techniques points to ultraviolet (UV) light from the Sun as
an important driving force in atmospheric evolution. Solar UV photons drive
the production of ozone in the atmosphere and yield ozone that is enriched in
17
O and 18O, thereby leaving a tell-tale isotopic signature. The ozone layer
began to form as the atmosphere gained oxygen, and has since shielded our
planet from harmful solar rays and made life possible on Earth's surface.
The discovery of isotope anomalies, where none were previously suspected,
adds a new tool to research on the relationships between shifts in atmospheric
chemistry and climate change. Detailed studies of polar-ice cores and
exposed deposits in Antarctic dry valleys may improve our understanding of
the history of the ozone hole.
Funding for this work came from the following institutions: NASA, The
NASA Astrobiology Institute, The National Science Foundation, The Jet
Propulsion Laboratory, and the Carnegie Institution of Washington.
Journal reference:
Douglas Rumble, 2005. A mineralogical and geochemical record of
atmospheric photochemistry.
American Mineralogist, 90(5-6):918-930.
http://www.minsocam.org/MSA/ammin/toc/2005/MJ05.html.
Marsbugs: The Electronic Astrobiology Newsletter, Volume 12, Number 17, 11 May 2005
Contact:
Douglas Rumble, III
Carnegie Geophysical Laboratory
Phone: 202 478- 8990
E-mail: [email protected]
2
through biological activity. The amount we found with Mars Express is very
tiny, only 10 parts per billion. But in martian conditions, methane could not
last more than 600 years. So methane is being produced somehow, and the
source must be producing at least 150 tons of methane per year for us to be
detecting it at 10 parts per billion in the atmosphere.
An
additional
article
on
this
subject
is
available
at
http://www.universetoday.com/am/publish/history_atmosphere_rocks.html.
HINTS OF HABITABILITY
By Bernard Foing
From Astrobiology Magazine
4 May 2005
The European Space Agency's Mars Express spacecraft has been orbiting
Mars for over a year. While the high resolution images of the planet's many
craters, volcanoes, and other features get the most notice, the spacecraft's
seven instruments have also gathered large amounts of data about the planet's
atmosphere, geology, and chemistry. Bernard Foing, ESA Chief Scientist,
provides an overview of the most notable discoveries made during Europe's
first trip to the Red Planet. In part two of this overview, Foing looks at how
these discoveries could help pinpoint the prospects for life on Mars.
There are a number of exoplanets which have been detected around other
stars, and they are all giant planets like Jupiter. The question is, "Are there
any habitable worlds similar to ours?" To answer this, it's crucial to see if
there are other habitable planets in our solar system. And so we look at Mars.
Kunowsky Crater MGS MOC Release MOC2-753,
10 June 2004.
Image credit: Mars Global
Surveyor, Malin Space Systems.
Left: Lower atmospheric clouds seen on Mars by Opportunity. Image
credit: NASA/JPL. Right: Mars Express above the thin martian upper
atmosphere successfully achieved orbital insertion on Christmas 2003.
Image credit: ESA.
The Mars Express SPICAM instrument, which is monitoring the martian
atmosphere, is addressing the question of the habitability of Mars. If there is
life on the surface of Mars now, could it survive? So this experiment is
measuring, for instance, the solar ultraviolet (UV) light which is penetrating to
the surface. It can also measure ozone and water. It can measure oxidants as
well—products that are scavengers for life. To do this, the SPICAM team
monitors a star when it is rising or setting on the horizon, and looks at how
light from the star is being absorbed by the atmosphere. That light absorption
helps them derive properties of the atmosphere.
They have found a very interesting correlation between ozone and water. It
seems that wherever there is an increase in atmospheric water, there is a
corresponding disappearance of ozone. So, on Mars, when water goes up,
ozone goes down.
We are very much dependent on a layer of ozone on Earth; it protects Earth
against UV radiation. Recent measurements on Earth indicate that the water
content of the Earth's atmosphere has increased from the water evaporation of
all the land surfaces and the oceans, maybe as an effect of global warming.
So if it's true that an increase in atmospheric water vapor causes the amount of
ozone to go down, then we have to be worried, because that could mean our
ozone layer will be further reduced.
Earth obviously has much more water than Mars, and we still do have an
ozone layer, so it's not a perfect correlation. But this planetary result from
Mars could be giving us a warning. It's an interesting application where you
explore another world, and suddenly you realize that there's something you
may have overlooked while on Earth.
The detection of methane on Mars is also very intriguing, because it relates to
the search for life. Methane is a gas that, on Earth, is produced mainly
So what is the source? One explanation would be chemistry activities in the
sub-surface. Methane could be produced where volcanic activity combines
with water and basalt. But there is also the possibility that the methane is the
result of methanogenic bacteria.
We have evidence for recent volcanic activity on Mars. There is some new
evidence, in polar areas, of small volcanic cones a few hundred meters high.
These are small volcanoes in the making, poking up through the ice. There
also seem to be recent volcanic activity in the calderas—large craters caused
by the collapse of the magma chamber after a volcanic eruption. You can
measure the age of the caldera in martian volcanoes by counting the impact
craters inside. From that, we've found that there are some calderas that are
very much younger than we thought. Some of them are maybe between 100
and 150 million years old, but we even found some that are a few million
years old. On a geological time scale, that's just like yesterday.
So we are discovering a new Mars, a Mars which is very active, with recent
volcanism. Mars was probably quite dry and cold during most of the last 3
billion years, but it could have experienced temporary episodes where water
was present in a few places. So in terms of the search for life, the possibility
of the habitability of Mars is much richer than we thought before. We see
new possible niches where we should search for the signature of life.
There's still a lot of work to do to put all of our discoveries into context,
instrument to instrument, but also with discoveries made by the Mars rovers.
The next step is to prepare new missions that will characterize some of the
potential habitats for life on Mars. We'll still follow the water, but we also
want to understand the carbon cycle, determine what energy sources are
available, search for hydrothermal hot spots, and look for any prebiotic
chemistry, or even biotic chemistry. Then we could pinpoint areas that could
be further explored with landers, to be followed by sample return missions.
Read the original article at http://www.astrobio.net/news/article1546.html.
Marsbugs: The Electronic Astrobiology Newsletter, Volume 12, Number 17, 11 May 2005
DID LIFE ARRIVE BEFORE THE SOLAR SYSTEM EVEN
FORMED?
By Jeff Barbour
From Universe Today
4 May 2005
The panspermia hypothesis proposes that life really gets around, jumping
from planet to planet—or even from star to star. Life might be everywhere!
Assuming this is true, how do single-celled bacteria make the journey through
the vacuum of space? Easy, they use chunks of rock as space ships, in a
process called lithopanspermia. And now, researchers from Princeton and the
University of Michigan think that life carrying rocks might have been right
there at the beginning of our solar system, keeping their tiny astronauts safe
and sound, frozen in statis until the planets formed and the right conditions let
them thaw out, stretch their proteins, and begin a process leading from
microbe to mankind.
3
Read the full article at
http://www.universetoday.com/am/publish/lithopanspermia.html.
ENVISAT MAKING SHARPEST EVER GLOBAL EARTH MAP
ESA release
5 May 2005
The most detailed portrait ever of the Earth's land surface is being created
with ESA's Envisat environmental satellite. The GLOBCOVER project aims
at producing a global land cover map to a resolution three times sharper than
any previous satellite map. It will be a unique depiction of the face of our
planet in 2005, broken down into more than 20 separate land cover classes.
The completed GLOBCOVER map will have numerous uses, including
plotting worldwide land use trends, studying natural and managed ecosystems
and modeling climate change extent and impacts.
A mosaic of global land cover from Envisat's MERIS instrument. The same sensor is to be used as the basis of ESA's GLOBCOVER project to create
the most detailed land cover map ever. For this mosaic a total of 1561 orbits taking place over the period May, July, October and November 2004 have
been used to screen the clouds. The color composite has been obtained by merging MERIS spectral bands 2, 3, 5, 7. Image credit: ESA.
Envisat's Medium Resolution Imaging Spectrometer (MERIS) instrument is
being systematically used in Full Resolution Mode for the project, acquiring
images with a spatial resolution of 300 meters, with an average 150 minutes of
acquisitions occurring daily. The estimate is that up to 20 terabytes of
imagery will be needed to mosaic together the final worldwide GLOBCOVER
map—an amount of data equivalent to the contents of 20 million books. The
image acquisition strategy is based around regional climate patterns to
minimize cloud or snow cover. Multiple acquisitions are planned for some
regions to account for seasonal variations in land cover.
Other Envisat sensors will work in synergy with MERIS. The Advanced
Synthetic Aperture Radar (ASAR) instrument will be used to differentiate
between similar land cover classes, such as wetlands and humid tropical
rainforests. And information from the satellite's Advanced Along Track
Scanning Radiometer will be used to correct for atmospheric distortion and to
perform 'cloud masking', or the elimination of cloud pixels.
An international network of partners is working with ESA on the two-year
GLOBCOVER project, which is taking place as part of the Earth Observation
Data User Element (DUE). Participants include the United Nations
Environment Programme (UNEP), the Food and Agriculture Organisation
(FAO), the European Commission's Joint Research Centre (JRC), the
International Geosphere-Biosphere Programme (IGBP) and the Global
Observations of Forest Cover and Global Observations of Land Dynamics
(GOFC-GOLD) Implementation Team Project Office.
This chart is a comparison of different mosaics of the same site in
Siberia acquired using the 30-metre spatial resolution Landsat ETM+,
the around ten times greater resolution MERIS and the 1-km resolution
SPOT 5 VGT. What is clear is that MERIS delivers a level of detail
closer to the former than the latter, making it a useful basis for the
GLOBCOVER mapping project. Image credit: JRC.
Marsbugs: The Electronic Astrobiology Newsletter, Volume 12, Number 17, 11 May 2005
4
environmental pollution and loss of biodiversity often do not respect national
or other artificial boundaries. An updated view of such problems—or their
effects—from interpreted space imagery should offer a large boost to UNEP's
effort to monitor the health of the planet and our changing environment."
Located at Friedrich-Schiller University in Jena, Germany, the GOFC-GOLD
Implementation Team Project Office is responsible for developing
international standards and methodology for global observations, and is
advising GLOBCOVER on classification issues.
The GLOBCOVER
classification system is being designed to be compatible with the Global Land
Cover map previously produced for the JRC for the year 2000, a onekilometer resolution map produced from SPOT-4 Vegetation Instrument data
and known as GLC 2000.
ESA's ten-instrument Envisat environmental satellite has been
observing the Earth for three years. Picture by EADS Astrium.
"UNEP anticipates being able to put the GLOBCOVER map to good use
within its program of assessment and early warning of emerging
environmental issues and threats, particularly those of a trans-boundary
nature," said Ron Witt of UNEP. "Changes in land cover patterns, effects of
GLOBCOVER will also serve to update and improve the European
Environment Agency's CORINE 2000 database, a 300-meter resolution land
cover map of the European continent based on a combination of updated land
cover maps and satellite imagery. Once worldwide MERIS Full Resolution
coverage is achieved, there will actually be two GLOBCOVER maps
produced. The first, GLOBCOVER V1, will be produced automatically by
mosaicking images together in a standardized way. The JRC is then utilizing
its GLC2000 experience to produce the more advanced GLOBCOVER V2 in
the second year, taking a regionally-tuned approach to the data. Some 30
teams worldwide will participate in analyzing and validating GLOBCOVER
products.
The Joint Research Centre of the European Commission previously produced the one-km-resolution Global Land Cover 2000 (GLC 2000) map
produced from SPOT 5 Vegetation Instrument data for the year 2000. The new global land cover maps produced during ESA's GLOBCOVER will be
compatible with GLC 2000, serving as an update. Image credit: JRC.
Acquired in a standardized 15 bands, the MERIS images are going to be
processed with an upgraded algorithm that includes an ortho-rectification fool,
correcting for altitude based on a digital elevation model (DEM) derived from
the Radar Altimeter-2 (RA-2), another Envisat instrument.
Read the original article at
http://www.esa.int/esaEO/SEMGSY2IU7E_environment_0.html.
Additional articles on this subject are available at:
http://www.universetoday.com/am/publish/high_resolution_global_map.html.
A VOLCANIC DINOSAUR DEBATE
By Leslie Mullen
From Astrobiology Magazine
9 May 2005
At least 50 percent of the world's species, including the dinosaurs, perished 65
million years ago. A large meteorite struck Mexico's Yucatan Peninsula
around the same time, and most scientists blame this impact for the mass
extinction. Yet there is nothing that directly links meteorite impacts with the
extinction of entire species. Scientists can recite a long list of the devastating
environmental consequences of a large meteorite impact, but they cannot
prove these effects have led to the simultaneous loss of life around the globe.
Answering the question of how and why such a large variety of species died
out at the same time is one of the greatest mysteries in paleontology.
While the exact reason for the Cretaceous-Tertiary (K-T) mass extinction is
still under debate, other past extinctions have been clearly linked with climate
change. As species become increasingly specialized to their environment, a
substantial or sudden change will tend to threaten their survival. The Earth
has gone through many cycles of extreme warming and cooling in its history,
with an associated rise and fall of species. Could such climate change have
played a role in the K-T extinction? One proponent of this theory is Dewey
McLean, a geologist at Virginia Polytechnic University who first published
the idea in the 1970s. McLean thinks the Chicxulub impact in Mexico just
added more stress to an environment that was already upset by the release of
copious amounts of volcanic gases.
His culprit for the outgassing is the Deccan Traps, an ancient lava flow in
west central India. This flood basalt volcanism, says McLean, upset the
Marsbugs: The Electronic Astrobiology Newsletter, Volume 12, Number 17, 11 May 2005
Earth's carbon cycle and led to long-term global warming. McLean suspects
the dinosaurs gradually became extinct through heat-induced reproductive
failure. He says that the higher temperatures, along with pH changes in ocean
water, led to the extinctions seen in marine life at the time.
Left: Outgassing lava flows: did they cause heat-induced
reproductive failure in cold-blooded dinosaurs? Right: The painting
titled "K/T Hit" by artist Donald E. Davis. This impact occured 65
million years ago, coinciding with the the dinosaur extinctions.
Image credit: Don Davis.
But Simon Kelley, a geologist at Open University in England, disagrees that
the volcanic gas from the Deccan Traps could have caused such warming. He
says the traps could have released, at most, only 2 percent of the carbon
dioxide (CO2) already in the atmosphere—not enough to trigger global
warming. In addition, he notes that volcanoes release sulfur dioxide (SO2),
which causes cooling rather than heating.
"The most recent example of massive volcanism, the Laki eruption of 1783-4
in Iceland, caused cooling in Europe and the northern USA, not heating," says
Kelley. "The bitter winter in Paris was documented by Benjamin Franklin,
envoy from the newly formed United States of America. Although SO2 is
washed out rapidly, the signal of volcanism should be a combination of the
both cooling and heating."
5
coastal areas. Deserts spread across the continent during the Triassic, but
there were still oases of tropical and temperate forests.
In the Jurassic, the great continent Pangea broke in half, creating Laurasia in
the north and Gondwanaland in the south. Rainfall increased, ocean levels
rose, and lush rain forests began to displace the deserts. These tropical forests
eventually blanketed much of two continents. By the end of the Cretaceous,
the two continents had separated into even smaller landmasses that were well
on their way toward their present continental shapes. The late Cretaceous
experienced extreme climate fluctuations, where temperatures would drop and
then rebound. This stressed the environment and likely resulted in the
extinction of many species.
Not only did the breakup of large continents into smaller chunks of land alter
the global climate, but all that tectonic movement also must have affected the
ocean cycles that help regulate climate. The El Niño and La Niña ocean
cycles of our own time are testament to how strong this marine influence can
be.
After the extinction of the dinosaurs and 50 percent of the world's species, the
early Tertiary (or Paleocene) era begins. Temperatures continued to fluctuate
during this time period, although they were generally cooler than the end of
the Mesozoic. This cooling may have been due in part to the gasses and
debris that was thrown into the atmosphere by the Chicxulub meteorite
impact. But the continental shuffling in the late Mesozoic also suggests a
great deal of volcanic activity must have been occurring at the time, throwing
out gases that could have changed the balance of atmospheric gases.
The greatest accumulation of lava on the Earth's surface at the time was in the
Deccan Traps of India. The Deccan lava first appeared millions of years
before the K-T extinctions. Sankar Chatterjee, a paleontologist at Texas Tech
University in Lubbock, Texas, says the fossil evidence shows that dinosaurs
lived quite happily right near these lava flows.
Kevin Pope, a geologist with Geo Eco Arc Research, says there is no evidence
for global warming following the K-T extinction. "In fact, the best records
show an abrupt cooling in the earliest Tertiary," says Pope.
"There are layers of sediment, lava, sediment, lava, and so on, indicating the
lava stopped and then started again over a long period of time," says
Chatterjee. "We find dinosaur eggs and bones throughout these layers, right
up to the K-T layer. So they lived around the Deccan Traps while this lava
was erupting."
Although McLean says that oxygen isotopes in ancient rocks indicate the
Earth endured long-term global warming from the Cretaceous through the
Tertiary eras, he admits the climate signal is mixed overall, with some rocks
indicating cooling instead of warming. "We have much work to do in
straightening out the K-T climate record," McLean says.
But then, right about 65 million years ago, the intermittent trickle of lava
became a vast flood. Geologists estimate that 90 percent of the lava in the
Traps was released at that time.
The jigsaw of continents that combined in the
supercontinent, Gondwanaland. Continental drift
and plate tectonics spread the land masses across
the globe.
Dinosaurs first appeared and flourished during the Mesozoic, a generally
warm era that lasted from 248 to 65 million years ago. Geologists split that
large chunk of time into the Triassic, Jurassic and Cretaceous periods. In the
Triassic, all the continents were joined together in one huge landmass called
Pangea. Such large swaths of land tend to influence their own climate,
resulting in very dry conditions, with greater seasonal fluctuations than in
A plot of data on mass extinctions. Dinosaurs survived the mass
extinction that took place about 200 million years ago. Image credit:
University of Chicago.
The K-T extinction is not the first mass extinction event to coincide with a
large outpouring of lava. An extensive lava flow in Siberia occurred about
250 million years ago, around the same time as the Permian-Triassic (P-Tr)
extinction event, the largest extinction of life in Earth's history. The P-Tr
extinction is often referred to as the "Great Dying," because 90 percent of
marine and 70 percent of land species perished.
Marsbugs: The Electronic Astrobiology Newsletter, Volume 12, Number 17, 11 May 2005
In 2004, a group of scientists announced that the Bedout crater, buried off the
northwestern coast of Australia, is about 250 million years old, and therefore
may coincide with the P-Tr extinction. The scientists say the Bedout crater
was created by a meteorite similar to the one that made the Chicxulub crater in
Mexico's Yucatan Peninsula.
If Bedout does prove to be an impact crater, it would point to another instance
where both a giant meteorite impact and massive flood basalt volcanism
occurred around the same time as a mass extinction. Yet the evidence
indicating Bedout is an impact crater is not as firmly established as the impact
evidence for Chicxulub, and some scientists say there is little proof Bedout is
anything but a volcanic structure.
Peter Ward, a geologist with the University of Washington in Seattle, doesn't
think the P-Tr extinction was caused by impact. He recently published a
paper in the journal, Science, that blames global warming on the Permian
extinction. Just as McLean thinks the Deccan Traps led to the K-T
extinctions, Ward thinks the Siberian lava flows could have eventually led to
the P-Tr mass extinction. Ward says that the extinction rate in the P-Tr was
much more gradual than the K-T, occurring almost imperceptibly over
millions of years. Yet McLean believes the K-T extinction rate also was slow
and incremental.
"I use the term 'K-T transition' because the biological turnover actually began
during the Late Cretaceous, and extended into the Early Tertiary," says
McLean. "As indicated by the geobiological record, there was no global
catastrophic extinction of most of Earth's life at the K-T boundary 65 million
years ago."
Most paleontologists disagree, however. The consensus is that the K-T
extinctions took place over a relatively brief point in time.
"The best paleontological data bases, like marine foraminifera and
dinoflagellates and terrestrial pollen, all point to an abrupt catastrophic event
at the K-T boundary," says Pope.
These microscopic fossils are preferable to dinosaur bones when it comes to
determining the time scale of the K-T extinction, says Pope, because dinosaur
fossils are so rare that they can not reliably indicate whether an extinction was
sudden or gradual. (A "short" period or "sudden" event in the fossil record
can describe something that occurred over hundreds or thousands of years,
due to the margin of error in the dating methods.)
6
notes that, historically, "there is a better correlation between volcanism and
mass extinctions than impact and mass extinction."
Even if the K-T was triggered by atmospheric changes due to massive
volcanic outgassing, that does not answer many other questions about the
extinction event. For instance, while the dinosaurs and many other species
perished 65 million years ago, a variety of other animals survived, including
the rodent-like mammals that eventually became human beings. If the
environment became so hostile that half of all life on Earth died, then how did
animals like birds, frogs, crocodiles, and mammals live on?
Journal reference:
Peter D. Ward, Jennifer Botha, Roger Buick, Michiel O. De Kock, Douglas H.
Erwin, Geoffrey H. Garrison, Joseph L. Kirschvink and Roger Smith, 2005.
Abrupt and gradual extinction among Late Permian land vertebrates in the
Karoo Basin, South Africa. Science, 307:709-714,
http://www.sciencemag.org/cgi/content/abstract/307/5710/709.
Read the original article at http://www.astrobio.net/news/article1552.html.
PLANETARY PROTECTION: X-RAY SUPER-FLARES AID
FORMATION OF "SOLAR SYSTEMS"
NASA release 05-120
10 May 2005
New results from NASA's Chandra X-ray Observatory imply that X-ray
super-flares torched the young Solar System. Such flares likely affected the
planet-forming disk around the early Sun, and may have enhanced the survival
chances of Earth. By focusing on the Orion Nebula almost continuously for
13 days, a team of scientists used Chandra to obtain the deepest X-ray
observation ever taken of this or any star cluster. The Orion Nebula is the
nearest rich stellar nursery, located just 1,500 light years away. These data
provide an unparalleled view of 1400 young stars, 30 of which are prototypes
of the early Sun. The scientists discovered that these young suns erupt in
enormous flares that dwarf—in energy, size, and frequency—anything seen
from the Sun today.
After the Cretaceous extinction that killed the dinosaurs, ferns were the
only plants left. Image credit: David J. Thomas.
Looking at the bone record we do have, it's clear that many dinosaur species
died out as a part of the natural extinction cycle long before the Chicxulub
meteorite hit the Earth, and other species were in decline. But species that
seemed to have robust populations before the impact suddenly disappear as
the fossil record enters the Tertiary. In fact, the fossil record indicates that
dinosaurs achieved their greatest species variety only a few million years
before they became extinct. This suggests that something dramatic must have
occurred to cause such a definitive end to the reign of the dinosaurs.
This Chandra image shows the Orion Nebula Cluster, a rich cluster of
young stars observed almost continuously for 13 days. The long
observation enabled scientists to study the X-ray behavior of young
Sun-like stars with ages between 1 and 10 million years. They
discovered that these young stars produce violent X-ray outbursts, or
flares, that are much more frequent and energetic than anything seen
today from our 4.6 billion-year-old Sun.
Image credit:
NASA/CXC/Penn State/E. Feigelson & K. Getman et al.
Most scientists who study the K-T believe the Chicxulub impact alone caused
the extinction, because the preponderance of evidence suggests the two events
are closely linked in time. But, says Kelley, "we still have a lot to learn." He
"We don't have a time machine to see how the young Sun behaved, but the
next best thing is to observe Sun-like stars in Orion," said Scott Wolk of
Marsbugs: The Electronic Astrobiology Newsletter, Volume 12, Number 17, 11 May 2005
Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. "We are
getting a unique look at stars between one and 10 million years old - a time
when planets form."
A key result is that the more violent stars produce flares that are a hundred
times as energetic as the more docile ones. This difference may specifically
affect the fate of planets that are relatively small and rocky, like the Earth.
7
as they form. Specifically, this turbulence can help prevent planets from
rapidly migrating towards the young star.
"Although these flares may be creating havoc in the disks, they ultimately
could do more good than harm," said Feigelson. "These flares may be acting
like a planetary protection program."
About half of the young suns in Orion show evidence for disks, likely sites for
current planet formation, including four lying at the center of proplyds (protoplanetary disks) imaged by Hubble Space Telescope. X-ray flares bombard
these planet-forming disks, likely giving them an electric charge. This charge,
combined with motion of the disk and the effects of magnetic fields should
create turbulence in the disk.
These two illustrations show a planet-forming disk of gas and dust
around a young star that is shown undergoing large flares. The left
panel shows the disk is initially smooth. The X-rays from the large
flares should heat the planet-forming disk and give it an electric
charge. This charge, combined with motion of the disk and the effects
of magnetic fields should create turbulence in the disk (shown at right).
This turbulence may knock rocky, Earth-like planets inwards and
outwards in their orbits, overcoming their tendency to rapidly migrate
through the disk towards the young star. Image credit: CXC/M. Weiss.
The numerous results from the Chandra Orion Ultradeep Project will appear
in a dedicated issue of The Astrophysical Journal Supplement in October,
2005. The team contains 37 scientists from institutions across the world
including the US, Italy, France, Germany, Taiwan, Japan and the Netherlands.
NASA's Marshall Space Flight Center, Huntsville, AL, manages the Chandra
program for NASA's Science Mission Directorate, Washington, DC.
Northrop Grumman of Redondo Beach, CA, was the prime development
contractor for the observatory. The Smithsonian Astrophysical Observatory
controls science and flight operations from the Chandra X-ray Center in
Cambridge, MA. Additional information and images are available at
http://chandra.harvard.edu and http://chandra.nasa.gov.
Contacts:
Erica Hupp
NASA Headquarters, Washington, DC
Phone: 202-358-1237
Steve Roy
NASA Marshall Space Flight Center, Huntsville, AL
Phone: 256-544-6535
Megan Watzke
Chandra X-ray Center, CfA, Cambridge, MA
Phone: 617-496-7998
These two illustrations show a planet-forming disk of gas and dust
around a young star that is undergoing small flares. In this case the
disk remains smooth and the rocky Earth-like planet migrates through
the disk towards the young star. Image credit: CXC/M. Weiss.
Read the original news release at
http://chandra.harvard.edu/press/05_releases/press_051005.html.
Additional articles on this subject are available at:
http://www.astrobio.net/news/article1554.html
http://www.universetoday.com/am/publish/superflares_protected_earth.html
"200 MILLION YEAR OLD" TREE PLANTED AT LONDON PARK
From Agence France-Presse and SpaceDaily
10 May 2005
A "Jurassic" tree dating from the dinosaur age and long thought to have been
extinct for 200 million years was planted Tuesday at a park in London by
British wildlife expert Sir David Attenborough. One of the rarest trees in the
world, the Wollemi Pine was found in Australia by a national parks officer,
David Noble, in 1994. The discovery astonished botanists worldwide who
had thought the tree died out millions of years ago.
This series of stills shows how X-ray flares from a young star affect a
planet-forming disk. Light from the young star is reflected off the inner
part of the disk, making it glow. The view zooms in to show small
white flares continually erupting on the surface of the young star. A set
of huge white magnetic loops then erupts from the star and hits the
inside edge of the disk, resulting in an extremely bright flare. X-rays
from the flare then heat up the planet-forming disk and will later result
in turbulence that affects the positions of planets. Image credit: NASA/
CXC/A.Hobart.
"Big X-ray flares could lead to planetary systems like ours where Earth is a
safe distance from the Sun," said Eric Feigelson of Penn State University in
University Park, and principal investigator for the international Chandra Orion
Ultradeep Project. "Stars with smaller flares, on the other hand, might end up
with Earth-like planets plummeting into the star."
According to recent theoretical work, X-ray flares can create turbulence when
they strike planet-forming disks, and this affects the position of rocky planets
Read the full article at http://www.terradaily.com/news/life-05zf.html.
X-PRIZE ARCHITECT TO SPEAK AT MARS SOCIETY
CONVENTION
Mars Society release
5 May 2005
Dr. Peter Diamandis, the founder of the X-Prize competition which resulted in
the creation of Burt Rutan's SpaceshipOne, the first privately developed
piloted spacecraft, will give a plenary talk at the 8th International Mars
Society convention, University of Colorado, Boulder August 11-14th, 2005.
Registration for the conference is now open at www.marssociety.org.
The Mars Society Convention provides an open forum for all those with new
ideas for furthering the exploration and/or settlement of Mars by public or
private means. Abstracts of no more than 300 words are currently being
solicited in all areas (scientific, engineering, politics, economics, public
policy, etc.) relating to the exploration or settlement of Mars. If you wish to
Marsbugs: The Electronic Astrobiology Newsletter, Volume 12, Number 17, 11 May 2005
speak, send your abstract by May 31, 2005 to [email protected]. Over
500 papers by Mars Society conference participants have been published in
books by Univelt and Apogee publishers. Another volume of Mars Society
proceedings published by Apogee, entitled, On to Mars 2, will hit bookstores
across the country this fall. If you want your ideas heard, participate and be
published.
Dr. Peter H. Diamandis' Biography
Dr. Peter Diamandis is a pioneer and leader in the commercial space arena.
He is the Chairman and CEO of the X PRIZE Foundation (www.xprize.org),
which awarded a $10,000,000 prize for private spaceflight won in October
2004 by Burt Rutan's SpaceShipOne. Dr. Diamandis is also the CEO of Zero
Gravity Corporation (www.nogravity.com) a commercial space company that
offers FAA-certified weightless flights utilizing a specially modified Boeing
727-200 aircraft.
Peter is a Founder and Trustee of the International Space University
(www.isunet.edu) where he served as the University's first Managing
Director. He is also co-Founder and Director of Space Adventures
(www.spaceadventures.com), the company which brokered Dennis Tito and
Mark Shuttleworth's flights to the International Space Station. Diamandis also
founded Students for the Exploration and Development of Space
(www.seds.edu) the world's large student space organization.
Dr. Diamandis received an undergraduate and graduate degree in aerospace
engineering from MIT and a medical degree from Harvard Medical School.
He has won numerous awards including the Konstantine Tsiolkovsky Award,
the Aviation & Space Technology Laurel, and the 2003 World Technology
Award for Space.
EXPLORATION LIFE AND MEDICAL SCIENCES (ELMS)
COALITION COMES TO LIFE; SUPPORTS SPACE BIOLOGY ON
THE INTERNATIONAL SPACE STATION
American Society for Gravitational and Space Biology release
5 May 2005
NASA's bold exploration efforts have created both opportunities and
challenges for space biologists in the United States and abroad. As a result,
the Exploration Life and Medical Sciences (ELMS) Coalition has been formed
to actively engage the scientific community and supporters in the public
policy process.
The ELMS Coalition is broadly inclusive: its founding organizations are
composed of life science organizations representing scientists from the US
and other countries, space entrepreneurs and public advocates .
The combined grassroots membership of the new coalition now numbers over
10,000.
8
Leading space biology systems experts, concerned with the need for space
exploration sustainability, have also joined the ELMS coalition. Dr. Roger
Hangarter, President, American Society of Plant Biologists, emphasizes that,
"it is critical for us to maintain a lead in biology research since it yields many
of the scientific discoveries that are essential to the core of our economic
growth and for enhancing Americans' quality of life. Moreover, long-term
human missions in space cannot afford to proceed without understanding the
impact of the space environment on the biology of astronauts and the plants
needed to sustain them."
ELMS founding members recognize the importance of creative
entrepreneurship, which helps drive mission-enabling space biology research
and technology. According to Tom Crabb, Co-Founder of ORBITEC, "small
business technology development and innovation has been a flagship in
providing necessary capabilities in space and for the International Space
Station, particularly in the safe and controlled management of biological
specimens and controlled environment systems. NASA's small business
commercialization activities from the Small Business Innovative Research
program provide unique biological test capabilities. This technology is
pivotal to investigating and resolving human health issues for the Vision for
Exploration."
ELMS supporters are not only finding their voice in Washington and in the
states, but are also listening carefully to Congress and NASA. Leaders in
Congress have become watchful of science on the space station. At a recent
hearing of the Senate Commerce and Space Sub-Committee, Senator Kay
Bailey Hutchinson (R-TX) and Senator Bill Nelson (D-FL) both made it clear
that maintaining scientific research on the station should be a priority.
Senator Hutchinson also proposed turning the space station, ISS, into a
Federal Laboratory. Others in the Senate have also expressed their interest in
maintaining ISS as a space biology research platform.
Senator Diane Feinstein (D-CA) offers this view: "Many fundamental
questions remain concerning the human health and physiological impacts of
long-term space travel. The ISS is an invaluable tool in facilitating this
nation's lead in space life sciences research, and provides the actual space
environment to perform the necessary research and testing to further our
understanding of human needs and technology requirements to support human
space exploration."
ELMS is also committed to the retention of current space biologists and the
training of the next generation. ELMS argues that this is a key to assuring that
America remains competitive in space.
Keeping the US international space partnerships in place is also on the ELMS
Agenda. Recently, JAXA, the Japanese Space Agency, expressed strong
concerns about the displacement of the centrifuge and other biological
research facilities on ISS, mirroring concerns of US researchers.
The ELMS Coalition's central focus for 2005 is to assure the realization of the
national vision to complete and utilize the International Space Station (ISS)
for space biology research.
ELMS looks forward to opening a fresh dialog with the new NASA
Administrator, Mike Griffin, about the essential role of space biology in the
Exploration quest. In Chris Brown's view, "it's great to have a scientist like
Mike Griffin leading NASA at such a critical time. He will understand that
basic, exploratory research is critical in a bold mission as putting humans onto
the surface of Mars. He will also understand that we can not afford a hiatus in
support for space biology research, if we are to meet the aggressive timelines
of the Vision. We are eager to work with him in defining the role of space
biology within NASA."
Dr. Russell Rayman, M.D., Director of the Aerospace Medical Association
notes that, "if we are to ensure the safety of our astronauts on long duration
missions, it is essential that we have effective countermeasures as well as an
autonomous system of in-flight medical care. These will require an
aggressive and well-funded research program."
ELMS Coalition contacts:
Chris Brown
ASGSB/ELMS Coalition
Phone: 919-513-2457
E-mail: [email protected]
In addition, ELMS supports a return on the taxpayer investment in ISS, via
medical benefits for the public. According to Kathleen Connell, incoming
Chair of the American Institute of Aeronautics and Astronautics Life Sciences
Technical Committee, "the biotechnology revolution can now be taken into
space, and may provide new insights into medical issues confronting the
earth's population. We have a national opportunity to return new knowledge
that may help solve both space exploration and terrestrial challenges. The
completion of the Centrifuge Accommodation Module (CAM) will provide a
facility that the research community and biotech industry can utilize to
generate new insights into human health from space. "
Kathleen M. Connell
AIAA Life Sciences Technical Committee/ELMS Coalition
Phone: (954) 561-5610
E-mail: [email protected]
According to Dr. Chris Brown, President of the American Society for
Gravitational and Space Biology, "the Vision for Space Exploration is
exciting and it is exactly what NASA should be doing. However, we must
make sure that the agency supports the basic biological research that is
foundational to its long-term success and sustainability."
Marsbugs: The Electronic Astrobiology Newsletter, Volume 12, Number 17, 11 May 2005
9
CASSINI UPDATES
NASA/JPL releases
Cassini Scientists Discover Pluto Kin is a Member of Saturn Family
NASA/JPL release 2005-071, 6 May 2005
Saturn's battered little moon Phoebe is an interloper to the Saturn system from
the deep outer solar system, scientists have concluded. The new findings
appear in the May 5 issue of the journal Nature.
"Phoebe was left behind from the solar nebula, the cloud of interstellar gas
and dust from which the planets formed," said Dr. Torrence Johnson, Cassini
imaging team member at NASA's Jet Propulsion Laboratory, Pasadena, Calif.
"It did not form at Saturn. It was captured by Saturn's gravitational field and
has been waiting eons for Cassini to come along."
The main event this week is the first Radio Science Subsystem (RSS)
occultation observation during the solar and Earth occultation at the Rev 7
periapse. At this time RSS will perform inbound and outbound ring and
Saturn occultation experiments. The occultation season runs from now until
September. During that time RSS will have 8 opportunities for collecting this
unique science data. The Optical Remote Sensing (ORS) instruments will
also participate by making a hi-phase observation of Saturn and its rings while
they are occulting the sun.
These two montages of images of Saturn's moon Phoebe, taken by
Cassini in June 2004, show the names provisionally assigned to 24
craters on this Saturnian satellite by the International Astronomical
Union. The craters are named for the Argonauts, explorers of Greek
mythology who sought the golden fleece. Argo was the name of their
ship. The largest crater, approximately 100 kilometers (62 miles)
across, is named after the leading Argonaut, Jason. Phoebe is an
outer moon of Saturn and is 220 kilometers (136 miles) across. The
two-image montage displays mosaics made of individual, very high
resolution images: 80 meters (260 feet) per pixel on the left; 200
meters (660 feet) per pixel on the right. Image credit: NASA/JPL/
Space Science Institute.
Cassini flew by Phoebe on its way to Saturn on June 11, 2004. Little was
known about Phoebe at that time. During the encounter, scientists got the first
detailed look at Phoebe, which allowed them to determine its makeup and
mass. With the new information they have concluded that it has an outer solar
system origin, akin to Pluto and other members of the Kuiper Belt.
Additional ORS activities include brief observations of Titan, Dione, and the
mutual interaction of Telesto and Tethys, the Imaging Science Subsystem
(ISS) will perform an azimuthal scan of the rings at low phase catching Atlas
at the same time, ISS and VIMS will focus on imaging Saturn's atmosphere at
phase angles of 100-120 degrees during the outbound segment after periapse,
and the Ultraviolet Imaging Spectrograph (UVIS) and Composite InfraRed
Spectrometer (CIRS) will conduct slow scans across the visible hemisphere to
provide ultraviolet and infrared spectra of the same territory.
During this time the Magnetospheric and Plasma Science (MAPS) instruments
will be conducting observations in survey mode. Survey mode is a generic
statement that means a MAPS instrument is on and collecting data
continuously at a low rate. The rate is different for each instrument. Not
overfilling the SSR is one reason to be in survey mode versus a higher data
collection rate mode.
"Cassini is showing us that Phoebe is quite different from Saturn's other icy
satellites, not just in its orbit but in the relative proportions of rock and ice. It
resembles Pluto in this regard much more than it does the other Saturnian
satellites," said Dr. Jonathan Lunine, Cassini interdisciplinary scientist from
the University of Arizona, Tucson.
Phoebe has a density consistent with that of the only Kuiper Belt objects for
which densities are known. Phoebe's mass, combined with an accurate
volume estimate from images, yields a density of about 1.6 grams per cubic
centimeter (100 pounds per cubic foot), much lighter than most rocks but
heavier than pure ice, which is about 0.93 grams per cubic centimeter (58
pounds per cubic foot). This suggests a composition of ice and rock similar to
that of Pluto and Neptune's moon Triton. Whether the dark material on other
moons of Saturn is the same primordial material as on Phoebe remains to be
seen.
Cassini Significant Events for 28 April - 4 May 2005
NASA/JPL release, 6 May 2005
The most recent spacecraft telemetry was acquired Wednesday from the
Madrid tracking station. The Cassini spacecraft is in an excellent state of
health and is operating normally. Information on the present position and
speed of the Cassini spacecraft may be found on the "Present Position" web
page located at http://saturn.jpl.nasa.gov/operations/present-position.cfm.
A scene straight out of science fiction, this fantastic view shows, from
left to right, Saturn's moon's Mimas, Dione and Rhea, on the far side of
Saturn's nearly edge-on rings. The trailing hemispheres of all three
moons are sunlit here, and wispy markings can be seen on the limbs of
both Dione and Rhea. The diameter of Mimas is 397 kilometers (247
miles), Dione is 1,118 kilometers (695 miles) and Rhea is 1,528
kilometers (949 miles). The image was taken in visible blue light with
the Cassini spacecraft narrow-angle camera on March 15, 2005, at a
distance of approximately 2.4 million kilometers (1.5 million miles) from
Saturn. The image scale is 14 kilometers (9 miles) per pixel. Image
credit: NASA/JPL/Space Science Institute.
Marsbugs: The Electronic Astrobiology Newsletter, Volume 12, Number 17, 11 May 2005
Thursday, April 28 (DOY 118):
Orbit trim maneuver #24 (OTM) was successfully completed on the spacecraft
tonight. This maneuver, performed near apoapsis, targets to the moon
Enceladus for the 175 km "Enceladus-2" flyby on July 14. The main engine
burn began at 7:15 PM PDT. A "quick look" immediately after the maneuver
showed the burn duration was 131.6 seconds long, giving a delta-V of 20.5
m/s. All subsystems reported nominal performance after the maneuver.
Between OTM-24 and OTM-25 the primary focus of science investigations is
on Saturn and ring occultations. There will be 5 revolutions of Cassini around
Saturn during this time where RSS will perform unique observations.
The last targeted encounter, Titan 5 occurred on April 16. The next targeted
encounter doesn't occur until Enceladus 2 on July 14. The first two OTMs of
the three maneuver set between T5 and E2 occurred on April 20, April 29, and
the last will occur July 8 just before the Enceladus flyby.
This over two-month break in OTMs was specifically built into the T18-5
Tour that Cassini is currently flying. The way it usually works is that
Navigation schedules three maneuvers between targeted flybys so the
spacecraft can get close enough to the target to assure that requirements for
pointing, and delta-v cost are met. There are no targeted encounters between
the end of April and the middle of July to allow for occultation science.
10
So how did RPWS see something from Cassini when the event doesn't get
there until May 23? What was observed on May 2 was the radio signal from
the CME shock which travels at the speed of light. The particles that make up
the CME shock front are only traveling at 700 -800 km/sec. That's pretty fast
but nothing like the speed of light. So the particles, which will interact
strongly with Saturn's magnetosphere and cause all sorts of interesting effects,
take 21 days to get out to Saturn's orbit from the sun.
When it arrives, if it hasn't dissipated, the CME shock will compress Saturn's
magnetosphere, trigger auroral emission and kilometer-wave radio emission,
and other effects detectable by RPWS and other MAPS instruments. This
particular event is related to the X-ray flare of 21:13 from solar active region
AR0758 observed on the eastern limb (77 degrees East) given the timing and
the Saturn-Sun-Earth geometry.
Tuesday, May 3 (DOY 123):
Navigation released an update to the reference trajectory today. This update
reflects the lowering of altitudes at Tethys in Rev 15, Hyperion in Rev 15, and
Enceladus in Rev 11. The new reference trajectory was discussed in detail at
today's Mission Planning Forum. RADAR playback options to avoid
coherency change induced data gaps were also discussed.
Wednesday, May 4 (DOY 124):
Today JPL held the annual Take your Child to Work Day. To support this
event, Cassini outreach prepared packets of material for the children of
Cassini program members. In addition, a model of the Cassini spacecraft was
on display alongside the "Cassini -Huygens Spacecraft" and "Spacecraft
Components" lithographs, which are available for download at
http://saturn.jpl.nasa.gov/multimedia/products/product-prints.cfm
A non-targeted flyby of Titan occurred today. An image of Saturn with the
rings edge-on is Astronomy Picture of the Day today. This kind of image is
only possible when the observer—in this case the Cassini spacecraft—is
crossing the ring plane.
Friday, April 29 (DOY 119):
Beginning tomorrow and running through the weekend, JPL will be hosting a
Saturn Educators Conference.
Cassini/Huygens scientists, engineers,
managers and educators will tell what they know about Saturn, Titan, and the
rings, icy moons, fields and particles, and what's planned over the next several
years. Thirty-three educators will participate in the event. A picture of
Saturn's moon Epimetheus is Astronomy Picture of the Day today.
As part of sequence development for S11, all nine Preliminary Sequence
Integration and Validation-2 SSR instrument expanded block (IEB) and
instrument direct IEB files required for uplink before the start of the S11
sequence have been moved out to the Program file repository. A command
approval meeting for these files will be held on May 5, and the files will be
uplinked to the spacecraft on May 9 and 10.
A Software Review/Certification Requirements meeting was held today for
Version 1.4 of ISS flight software. The software was approved and is
currently planned to be uplinked to the spacecraft in mid-June. Uplink
Operations sent a number of commands to the spacecraft today. Among them
were Live Movable Block files that will execute on DOY 123 in support of
the RSS occultation observations, an update to the Tethys vector based on the
OTM-24 Orbit Determination Solution, CIRS trigger commands, and a
Cassini Plasma Spectrometer housekeeping memory readout address update.
Monday, May 2 (DOY 122):
Non-targeted flybys of Tethys and Epimetheus occurred today. By the way, if
you are interested in more information on Saturn's moons, don't forget to
checkout the Cassini Web site, specifically the new moons page,
http://saturn.jpl.nasa.gov/science/moons/index.cfm.
The first of 8 RSS occultation experiments began today at 9:13 PM and will
continue until about 3:00 AM tomorrow morning. More details will be
available next week on how the observations went.
The Radio and Plasma Wave Experiment (RPWS) observed a Type II solar
burst, indicative of a coronal mass ejection (CME) shock, on May 2 at 23:45
UTC. Given one way light time from the Sun to Saturn this would correspond
roughly to a launch time of the ejection from the Sun at 22:25 UTC, one hour
and 20 minutes earlier. The shock front from the CME propagates through the
solar system at about 700 to 800 km/sec, and is projected to arrive at Saturn,
after traveling more than 1 billion km, on or about May 23.
This view shows one of the huge impact basins on the terminator of
Saturn's moon Iapetus and a smaller, but still fairly large, crater near
the southern bright-dark boundary. Just visible near the western limb,
in the dark territory of Cassini Regio, is the moon's mysterious
equatorial ridge. The ridge was discovered in Cassini images (see
PIA06166) and reaches 20 kilometers (12 miles) high in places. This
view shows principally the leading hemisphere on Iapetus. North is up
and tilted 15 degrees to the right. Iapetus is 1,468 kilometers (912
miles) across. The image was taken with the Cassini spacecraft
narrow-angle camera on March 19, 2005, through spectral filters
sensitive to wavelengths of infrared light centered at 752 nanometers.
The view was acquired at a distance of approximately 1.4 million
kilometers (880,000 miles) from Iapetus and at a Sun-Iapetusspacecraft, or phase, angle of 70 degrees. Resolution in the original
image was 8 kilometers (5 miles) per pixel.
Image credit:
NASA/JPL/Space Science Institute.
As part of sequence development for S11, the final merged sequence products
have been published to the Program file repository and are available for
Marsbugs: The Electronic Astrobiology Newsletter, Volume 12, Number 17, 11 May 2005
review by the sequence development team. The final sequence approval
meeting will be held on Monday of next week.
A delivery coordination meeting for the Cassini Information Management
System was held today. This delivery was focused on new functionality for
Science Planners to aid in automated resource checking of sequence planning
products.
Cassini Finds New Saturn Moon That Makes Waves
NASA/JPL release 2005-74, 10 May 2005
In a spectacular kick-off to its first season of prime ring viewing, which began
last month, the Cassini spacecraft has confirmed earlier suspicions of an
unseen moon hidden in a gap in Saturn's outer A ring. A new image and
movie show the new moon and the waves it raises in the surrounding ring
material. The moon, provisionally named S/2005 S1, was first seen in a timelapse sequence of images taken on May 1, 2005, as Cassini began its climb to
higher inclinations in orbit around Saturn. A day later, an even closer view
was obtained, which has allowed a measure of the moon's size and brightness.
The new images can be seen at
http://saturn.jpl.nasa.gov,
http://www.nasa.gov/cassini and http://ciclops.org.
11
The Keeler gap edges also bear similarities to the scalloped edges of the 322kilometer-wide (200-mile) Encke gap, where the small moon Pan (25
kilometers, or 16 miles across) resides. From the size of the waves seen in the
Encke gap, imaging scientists were able to estimate the mass of Pan. They
expect to do the same eventually with this new moon.
"Some of the most illuminating dynamical systems we might hope to study
with Cassini are those involving moons embedded in gaps," said Dr. Carolyn
Porco, imaging team leader at the Space Science Institute. "By examining
how such a body interacts with its companion ring material, we can learn
something about how the planets in our solar system might have formed out of
the nebula of material that surrounded the Sun long ago. We anticipate that
many of the gaps in Saturn's rings have embedded moons, and we'll be in
search of them from here on."
Additional closer observations of the new body may take place in the next
several months, as Cassini continues its intensive survey of Saturn's beautiful
and mysterious rings.
The Cassini-Huygens mission is a cooperative project of NASA, the European
Space Agency and the Italian Space Agency. JPL, a division of the California
Institute of Technology in Pasadena, manages the Cassini mission for NASA's
Science Mission Directorate, Washington, DC. For Phoebe images and more
information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov
and http://www.nasa.gov/cassini.
Contact:
Carolina Martinez
Jet Propulsion Laboratory, Pasadena, CA
Phone: 818-354-9382
Cassini's confirmation that a small moon orbits within the Keeler gap in
Saturn's rings is made all the more exciting by this image, in which the
disk of the 7 kilometer-wide body (4-miles) is resolved for the first time.
Image credit: NASA/JPL/Space Science Institute.
The images show the tiny object in the center of the Keeler gap and the wavy
patterns in the gap edges that are generated by the moon's gravitational
influence. The Keeler gap is located about 250 kilometers (155 miles) inside
the outer edge of the A ring, which is also the outer edge of the bright main
rings. The new object is about 7 kilometers (4 miles) across and reflects about
half the light falling on it—a brightness that is typical of the particles in the
nearby rings.
Preston Dyches
Cassini Imaging Central Laboratory for Operations
Space Science Institute, Boulder, CO
Phone: 720-974-5859
Additional articles on this subject are available at:
http://www.astrobio.net/news/article1549.html
http://spaceflightnow.com/cassini/050505icymoons.html
http://www.universetoday.com/am/publish/phoebe_outer_solar_system.html
http://www.universetoday.com/am/publish/spinning_hyperion.html
ROVER TEAM TESTS MARS MOVES ON EARTH
NASA/JPL release 2005-072
6 May 2005
"It's too early to make out the shape of the orbit, but what we've seen so far of
its motion suggests that it is very near the exact center of the gap, just as we
had surmised," said Dr. Joseph Spitale, imaging team associate and planetary
scientist at the Space Science Institute in Boulder, Colo. The new moonlet
orbits approximately 136,505 kilometers (84,820 miles) from the center of
Saturn. More Cassini observations will be needed to determine whether the
moon's orbit around Saturn is circular or eccentric. S/2005 S1 is the second
known moon to exist within Saturn's rings. The other is Pan, 25 kilometers
(16 miles) across, which orbits in the Encke gap. Atlas and other moons exist
outside the main ring system, as do the two F ring shepherd moons,
Prometheus and Pandora.
Imaging scientists had predicted the new moon's presence and its orbital
distance from Saturn after last July's sighting of a set of peculiar spiky and
wispy features in the Keeler gap's outer edge. The similarities of the Keeler
gap features to those noted in Saturn's F ring and the Encke gap led imaging
scientists to conclude that a small body, a few kilometers across, was lurking
in the center of the Keeler gap, awaiting discovery.
"The obvious effect of this moon on the surrounding ring material will allow
us to determine its mass and test our understanding of how rings and moons
affect one another," said Dr. Carl Murray, imaging team member from Queen
Mary, University of London. An estimate of the moon's mass, along with a
measure of its size, yields information on its physical makeup. For instance,
the new moonlet might be quite porous, like an orbiting icy rubble pile. Other
moons near the outer edge of Saturn's rings—like Atlas, Prometheus and
Pandora—are also porous. Whether a moon is porous or dense says
something about how it was formed and its subsequent collision history.
Rover engineers check how a test rover moves in material chosen to
simulate some difficult Mars driving conditions. The scene is inside the
In-Situ Instrument Laboratory at NASA's Jet Propulsion Laboratory,
Pasadena, CA. These tests in early May 2005 were designed to help
plan the best way for the rover Opportunity to drive off of a soft-sand
dune that the rover dug itself into the previous week. The mixture of
sandy and powdery material brought in for these specific tests
matched the way the soil underneath Opportunity caked onto wheels,
filling the spaces between the cleats on the wheels. Image credit:
NASA/JPL.
Marsbugs: The Electronic Astrobiology Newsletter, Volume 12, Number 17, 11 May 2005
Mars rover engineers are using a testing laboratory to simulate specific Mars
surface conditions where NASA's rover Opportunity has spun its wheels in a
small dune. Careful testing is preceding any commands for Opportunity to
resume moving to get out of the dune and continue exploring. The rover team
at NASA's Jet Propulsion Laboratory, Pasadena, CA, has cooked up recipes
combining various sandy and powdery materials for the best simulation on
Earth of the dune where Opportunity dug itself in to wheel-hub depth last
week. The team has not asked Opportunity to turn its wheels at all since the
rover bogged down during a drive on April 26.
"We choose to proceed cautiously, so we don't expect to begin actually
driving out of the dune before next week, possibly later," said Jim Erickson,
rover project manager at JPL. "Both Opportunity and Spirit have already
provided many more months of scientific exploration than anyone expected.
By taking good care of them, we hope to keep them exploring for more
months to come. Tests so far have sustained our optimism about
Opportunity's ability to drive out of this dune, but we have more testing ahead
to understand how robust that capability is."
Opportunity had driven about 40 meters (131 feet) of a planned 90-meter
(295-foot) drive on the rover's 446th martian day when its wheels began
slipping. The rover was driving backwards at the time. The team frequently
alternates between backwards and forwards driving to keep wheel lubrication
well distributed. The wheels kept rotating enough times to have covered the
rest of the distance if they hadn't been slipping, but the rover eventually barely
inched forward. After a turn at the end of the planned drive, Opportunity
sensed that it had not turned properly and stopped moving.
Opportunity is positioned across the ridge of an elongated dune or ripple of
soft sand that is about one-third meter (one foot) tall and 2.5 meters (8 feet)
wide. "We've climbed over dozens of ripples, but this one is different in that
it seems to be a little taller and to have a steeper slope, about 15 degrees on
part of its face," said Mark Maimone, a JPL rover mobility engineer.
12
Experiments indicate that in this more powdery material, the test rover
positioned comparably to Opportunity can drive out after some initial wheelspinning. More testing, analysis, planning and review will precede any actual
commands for Opportunity to begin driving away from the dune.
Meanwhile, Opportunity has been using its cameras to study its surroundings
at the edge of a region called "Etched Terrain." Since landing more than 15
months ago, it has driven 5.35 kilometers (3.32 miles). Spirit, halfway around
Mars, has recently been using all of its research tools to examine an outcrop
called "Methuselah," the first outcrop of layered rock that Spirit has found.
The rover has also been taking short movies of dust-carrying whirlwinds
called "dust devils." On some afternoons, the rover sees several at once
moving across the plain. Spirit has driven a total of 4.31 kilometers (2.68
miles).
JPL, a division of the California Institute of Technology in Pasadena, has
managed NASA's Mars Exploration Rover project since it began in 2000.
Images and additional information about the rovers and their discoveries are
available
on
the
Internet
at
http://www.nasa.gov/vision/universe/solarsystem/mer_main.html
and
http://marsrovers.jpl.nasa.gov.
Contact:
Guy Webster
Jet Propulsion Laboratory, Pasadena, CA
Phone: 818-354-6278
Additional articles on this subject are available at:
http://www.space.com/missionlaunches/050509_opportunity_sand.html
http://www.spacedaily.com/news/mars-mers-05zt.html
http://www.marsdaily.com/news/mars-mers-05zs.html
http://www.marsdaily.com/news/mars-mers-05zu.html
http://www.marsdaily.com/news/mars-mers-05zv.html
MARS EXPRESS UPDATES
ESA releases
Crater Holden and Uzboi Vallis
ESA release, 9 May 2005
This movie clip frame shows a single dust devil—a whirlwind that lofts
dust into the air—that passed near the bottom of the hillside where
NASA's Mars Exploration Rover Spirit was located at the time. The
proximity of the dust devil makes this sequence the best obtained so
far for showing details of its structure. Spirit's navigation camera took
these images on the rover's 446th martian day, or sol (April 15, 2005).
Contrast has been enhanced for anything in the images that changes
from frame to frame, that is, for the dust devil. Image credit:
NASA/JPL.
These images, taken by the High Resolution Stereo Camera (HRSC) on board
ESA's Mars Express spacecraft, show the outlet channel of the Uzboi Vallis
system into Crater Holden on Mars. The HRSC obtained these images during
orbit 511 with a ground resolution of approximately 45 meters per pixel. The
scenes show the region of Noachis Terra, over an area centered at about 26º
South and 325º East.
Last week, engineers arranged a simulated dune using sand that was already at
JPL's rover testing facility and put a test rover into a comparably dug-in
position. The test rover had no difficulty driving away, even when sunk in
belly-deep. However, that sand offered better traction than the finer, looser
material that appears to make up the surface at Opportunity's current position.
"We needed to do tests using material more like what Opportunity is in,
something that has a fluffier texture and cakes onto the wheels," said JPL
rover engineer Rick Welch, who is leading the tests.
Experimenting with different mixtures, engineers and scientists came up with
a recipe that includes play sand for children's sandboxes, diatomaceous earth
for swimming pool filters and mortar clay powder. Then they went to several
home supply and hardware stores to find enough bags and boxes of the
ingredients to make more than 2 tons of the simulated Mars sand for more
realistic mobility tests, said JPL rover mobility engineer Jeff Biesiadecki.
Dr. Robert Sullivan of Cornell University, Ithaca, NY, a rover science team
member, worked with engineers in the JPL testbed to match the properties of
the test sand as closely as possible with those of the sand beneath Opportunity,
based on images of wheels and wheel tracks on Mars. "We found that when
the wheels dig in, the material we're using does stick to the wheels and fills
the gaps between the cleats, but it doesn't stick when you're just driving over
it. That's good because it's the same as what we see in the images from
Opportunity," Sullivan said.
Color image of Crater Holden and Uzboi Vallis.
ESA/DLR/FU Berlin (G. Neukum).
Image credit:
The valley of Uzboi Vallis begins in the region of Argyre Planitia and crosses
the southern highlands in the direction of the northern lowlands. It connects
several large impact craters, such as the 140 kilometer-wide Crater Holden
seen in the main image. Due to a layer of haze close to the base of Holden,
the area within the crater appears lighter colored and slightly less detailed than
the surrounding area. A small, dark dune-field can be seen in the eastern half
Marsbugs: The Electronic Astrobiology Newsletter, Volume 12, Number 17, 11 May 2005
of the crater floor. It indicates the role of wind in the morphological evolution
of Crater Holden.
Map showing Crater Holden and Uzboi Vallis in context. The Mars
Express HRSC obtained the images of the region of Noachis Terra,
over an area centred at about 26º South and 325º East. Image credits:
ESA/DLR/FU Berlin (G. Neukum).
This is close-up of the image obtained by Mars Express on 14 June
2004. North is to the left. It shows a well-preserved alluvial fan (i.e. a
fan-shaped deposit of water-transported material) in the southern part
of Crater Holden. Image credits: ESA/DLR/FU Berlin (G. Neukum).
The terrain within Crater Holden is the result of a long and varied evolution.
The numerous smaller craters inside Holden indicate that the crater is old.
Many smaller craters on the floor of Holden are covered with sediments,
which were deposited after the formation of these craters and indicate that
they are older than the unfilled small craters.
The central mount of Holden is partly hidden, because it has also been
covered by sediments. The rim of the crater has been cut by gullies, which
13
sometimes form small valley networks. In the southern part of Crater Holden,
well-preserved alluvial fans (fan-shaped deposits of water-transported
material) are visible at the end of some gullies. In other parts of the crater
rim, the alluvial fans are less distinct and partly covered by younger talus
cones (cone-shaped piles of debris from rock falls at the base of slopes).
This is a close-up of the image taken by Mars Express on 14 June
2004. Uzboi Vallis enters Crater Holden from the south-west. Two
distinct phases of its development can be seen. In the first phase, a
valley was formed up to 20 kilometers wide. Later, a smaller channel
was cut into the valley floor. The end of the small channel has been
blocked by a landslide from the crater rim.
Image credits:
ESA/DLR/FU Berlin (G. Neukum).
This perspective view of the rim of Crater Holden was taken by Mars
Express on 14 June 2004. It looks south, the alluvial fan can be seen
in the centre, and the channel system of Uzboi Vallis is visible at right.
The rim of the crater has been cut by gullies, which sometimes form
small valley networks.
Image credits: ESA/DLR/FU Berlin (G.
Neukum).
Uzboi Vallis enters Crater Holden from the south-west. Two distinct phases
of its development can be seen. In the first phase, a valley was formed up to
20 kilometers wide. Later, a smaller channel was cut into the valley floor.
The end of the small channel has been blocked by a landslide from the crater
rim. The deepest parts of the valley floor are more than 1600 meters below
the surrounding area. The numerous valleys at the flanks of Uzboi Vallis
indicate that water probably played a major role in the formation and
Marsbugs: The Electronic Astrobiology Newsletter, Volume 12, Number 17, 11 May 2005
14
evolution of this region. Most of the valleys have been covered by younger
sediments, indicating they have been inactive in recent geological time.
missions ever flown to the Red Planet. Mars Express was launched on 2 June
2003 and entered Mars orbit in December 2003.
The color images were processed using the HRSC nadir (vertical view) and
three color channels. The perspective views were calculated from the digital
terrain model derived from the stereo channels. The 3D anaglyph image was
created from the nadir channel and one of the stereo channels. Stereoscopic
glasses are needed to view the 3D image. Image resolution has been
decreased for use on the internet.
Read the original news release at
http://www.esa.int/SPECIALS/Mars_Express/SEMQGXY5D8E_0.html.
Read the original news release at
http://www.esa.int/SPECIALS/Mars_Express/SEM9YX2IU7E_0.html.
Deployment of second MARSIS boom delayed
ESA release, 9 May 2005
The deployment of the second antenna boom of the Mars Express Sub-Surface
Sounding Radar Altimeter (MARSIS) science experiment has been delayed
pending investigation of an anomaly found during deployment of the first
antenna boom. The anomaly was discovered on 7 May towards the end of the
first deployment operations. Deployment of the first boom started on
Wednesday 4 May. The problem with the boom was confirmed by flight
control engineers working at ESA's European Space Operations Centre
(ESOC) in Darmstadt, Germany, on 7 May, after which further activity was
stopped pending a full assessment of the situation. The decision to delay
deployment of Boom 2 pending clarification of the situation and implications
was made on 8 May.
Additional articles on this subject are available at:
http://www.astrobio.net/news/article1553.html
http://www.marsdaily.com/news/marsexpress-05n.html
http://www.marsdaily.com/news/marsexpress-05o.html
http://www.marsdaily.com/news/marsexpress-05q.html
http://www.space.com/missionlaunches/050509_marsis_delay.html
http://spaceflightnow.com/news/n0505/09marsradar/
http://www.universetoday.com/am/publish/crater_holden_uzboi-vallis.html
http://www.universetoday.com/am/publish/marsis_1st_boom_problem.html
MARS GLOBAL SURVEYOR IMAGES
NASA/JPL/MSSS release
28 April - 4 May 2005
The following new images taken by the Mars Orbiter Camera (MOC) on the
Mars Global Surveyor spacecraft are now available.
Trough in Tempe (Released 28 April 2005)
http://www.msss.com/mars_images/moc/2005/04/28/
Lycus Sulci Terrain (Released 29 April 2005)
http://www.msss.com/mars_images/moc/2005/04/29/
Wind Erosion in Tithonium (Released 30 April 2005)
http://www.msss.com/mars_images/moc/2005/04/30/
Lava Flow Front (Released 01 May 2005)
http://www.msss.com/mars_images/moc/2005/05/01
Layered Trough Walls (Released 02 May 2005)
http://www.msss.com/mars_images/moc/2005/05/02
Mars at Ls 211 Degrees (Released 03 May 2005)
http://www.msss.com/mars_images/moc/2005/05/03
Fretted Terrain Valley (Released 04 May 2005)
http://www.msss.com/mars_images/moc/2005/05/04
All of the Mars Global Surveyor images
http://www.msss.com/mars_images/moc/index.html.
MARSIS prospecting for water. Image credit: ESA.
Mission controllers were able to determine that 12 of the 13 boom segments
of Boom 1 were correctly locked into position. However, one of the final
segments, possibly #10, had deployed but was not positively locked into
position. It was determined that deployment of the second boom should be
delayed in order to determine what implications the anomaly in the first boom
may have on the conditions for deploying the second.
This decision is in line with initial plans which had allowed for a delay should
any anomalous events occur during the first boom deployment.
Mission staff will now take the time necessary to investigate the boom
situation. Foreseen outcomes include confirming that all segments of Boom 1
have been locked into place and determining how the deployment of Boom 1
may affect that of Boom 2. All efforts will be made to ensure the safety of the
spacecraft overall and to minimize any effects on the operations of ongoing
science activity on board Mars Express.
The MARSIS experiment is to map the martian sub-surface structure to a
depth of a few kilometers. The instrument's 40-meter long antenna booms
will send low frequency radio waves towards the planet, which will be
reflected from any surface they encounter. MARSIS is one of seven science
experiments carried on board Mars Express, one of the most successful
are
archived
at
Mars Global Surveyor was launched in November 1996 and has been in Mars
orbit since September 1997. It began its primary mapping mission on March
8, 1999. Mars Global Surveyor is the first mission in a long-term program of
Mars exploration known as the Mars Surveyor Program that is managed by
JPL for NASA's Office of Space Science, Washington, DC. Malin Space
Science Systems (MSSS) and the California Institute of Technology built the
MOC using spare hardware from the Mars Observer mission. MSSS operates
the camera from its facilities in San Diego, CA. The Jet Propulsion
Laboratory's Mars Surveyor Operations Project operates the Mars Global
Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics,
from facilities in Pasadena, CA and Denver, CO.
MGS FINDS VIKING LANDER 2 AND MARS POLAR LANDER
(MAYBE)
MSSS release
5 May 2005
Viking Lander 2
One of the more interesting and appealing activities of the Mars Orbiter
Camera (MOC) observational objectives identified in the original 1985 Mars
Observer proposal was to image landers on the martian surface. The scientific
goal of this objective is to place the landers into their geologic context, which
in turn helps the science community to better understand the results from the
landers. In addition to this, the MOC team believed that it would be "really
neat" to see the landers sitting on the surface. In previous releases, we have
shown images of Viking Lander 1, Mars Pathfinder, and the two Mars
Exploration
Rovers,
Spirit
and
Opportunity
Marsbugs: The Electronic Astrobiology Newsletter, Volume 12, Number 17, 11 May 2005
(http://www.msss.com/mars_images/moc/themes/LANDINGS.html). To this
group of landers we can now add with certainty Viking Lander 2 (VL-2), the
location of which has been uncertain by many kilometers for nearly 30 years.
We also believe that we have found a candidate for the location of the Mars
Polar Lander, which failed without a trace on 3 December 1999.
15
bright spot near its center (the lander). In 2000, we found one example (see
figure) that met these criteria, but in the absence of any substantive,
corroborating evidence, the interpretation that this was MPL and its parachute
were considered to be extremely speculative.
Observations by MGS MOC in 2004 of the Mars Exploration Rover (MER)
landing sites provided guidance for a re-examination of the previously
identified MPL candidate. For example, the material from which the MPL
and MER parachutes are made is similar, and its brightness in MOC images
can be calculated, at least in a relative sense, as a function of sun angle. The
brightness of the candidate "parachute" in the MPL candidate location image
turns out to be consistent with it being the same material. The brightness
difference of the ground disturbed by rocket blast at the MER sites is similar
to the brightness difference seen in the MPL candidate image, again adjusted
for the difference in illumination and viewing angles. These consistencies
lend credibility to this tentative identification.
The first figure (above) shows: (A) a mosaic of Viking Orbiter images
obtained in the 1970s at a resolution of 75 m/pixel, (B) a typical Mars Global
Surveyor (MGS) MOC narrow angle camera view at about 3 meters/pixel
(25x higher resolution than the Viking images), and (C, D) sections of a
cPROTO image at 0.5 m/pixel. The second figure (above) shows an extreme
enlargement of the feature identified as Viking Lander 2, compared to a
schematic drawing of the lander in the orientation determined during the
Viking mission.
Finding Viking 2 has been a challenge owing to the extreme subtlety of
horizon features visible in the lander panoramas and relatively inaccurate
radio tracking data. Without the diligent work of Timothy J. Parker of the Jet
Propulsion Laboratory and Philip Stooke of the University of Western
Ontario, we wouldn't really have known where to point the MOC. Using the
best estimated locations based on sightline studies to guide our targeting, we
finally located the lander amid the remarkably homogenous terrain. Viking
Lander 2 touched down on Utopia Planitia on 3 September 1976.
Mars Polar Lander
The loss of Mars Polar Lander in December 1999 was a traumatic experience
not only for those of us intimately involved in the mission, but also for the
U.S. Mars Exploration Program. Following the failure, exhaustive reviews of
what happened and why led to major shifts in the way planetary exploration
was implemented. Without telemetry, the cause of the failure could only be
surmised. It would be extremely important if, through some observation, it
were possible to confirm the failure mode.
Shortly after the loss of Mars Polar Lander (MPL), the Mars Global Surveyor
MOC was employed to acquire dozens of 1.5 m/pixel images of the landing
uncertainty ellipses, looking for any evidence of the lander and its fate. The
criteria we used in searching for MPL required a bright feature of irregular or
elongated shape (the parachute) within about 1 kilometer (0.62 miles) of a
location that included a dark area (rocket-disturbed martian dirt) and a small,
If these features really are related to the MPL landing, what can we surmise
about that landing from the image? First, we can tell that MPL's descent
proceeded more-or-less successfully through parachute jettison and terminal
rocket firing. The relative location of the candidate parachute and lander is
consistent with the slight west-to-east wind seen in dust cloud motion in the
area around the date of landing. The blast-disturbed area is consistent with the
engines continuing to fire until the vehicle was close to the ground. How
close is not known. The larger MER retrorockets fired at about 100 m altitude
and continued firing until the engines were about 20-25 m above the surface;
the candidate MPL disturbance is roughly the same size, but whether this
means the engines were firing as close to the ground as the MER rockets
cannot be determined. These interpretations are consistent with the proposed
MPL mode of failure: the engines fired at the correct time and altitude and
continued firing until the flight software checked to see if an electronic
message indicated that the landing leg contact switch had been set. Since the
initial leg deployment several kilometers above the surface apparently induced
sufficient motion to trigger this message, the software stopped the engines as
soon as the check was made, about 28-30 seconds into the 36-40 second burn.
MPL was probably at an altitude of about 40 m, from which it freely fell.
This is equivalent to a fall on Earth from a height of about 40 feet. The
observation of a single, small "dot" at the center of the disturbed location
would indicate that the vehicle remained more-or-less intact after its fall.
What is important about having a candidate for the Mars Polar Lander site? It
gives the MOC team a place to target for a closer look, using the compensated
pitch and roll technique known as "cPROTO." Examples of cPROTO images
and a description of this capability, developed by the MGS team in 2003 and
2004, were discussed in a MOC release on 27 September 2004
(http://www.msss.com/mars_images/moc/2004/09/27/). Without a candidate
for targeting a cPROTO image, it would take more than 60 Earth years to
cover the entire Mars Polar Lander landing ellipse with cPROTO images,
because the region spends the better part of each Mars year covered with
carbon dioxide frost, part of each winter is spent in darkness, and, because of
several uncertainties involved with the technique, it often takes two, three, or
more tries before a cPROTO image hits a specific target. Now that a
candidate site for Mars Polar Lander has been identified, we have a cPROTO
target, which may permit us to obtain an image of about 0.5 meters per pixel
(allowing objects approximately 1.5-2.5 meters in size to be resolved) during
southern summer this year. At the present time (May 2005), the landing site is
just beginning to lose its cover of seasonal carbon dioxide frost.
Read the original news release at
http://www.msss.com/mars_images/moc/2005/05/05/index.html.
Marsbugs: The Electronic Astrobiology Newsletter, Volume 12, Number 17, 11 May 2005
Additional articles on this subject are available at:
http://www.space.com/missionlaunches/050506_mpl_candidate.html
http://spaceflightnow.com/news/n0505/05mpl/
http://www.universetoday.com/am/publish/mars_polar_lander_found.html
MARS ODYSSEY THEMIS IMAGES
NASA/JPL/ASU release
2-6 May 2005
16
"The Earth fly-by represented the first real chance to calibrate and validate the
performance of the Rosetta's instruments on a real space object, to make sure
everything works fine at the final target," said Angioletta Coradini, Principal
Investigator for the Visible and Infrared Thermal Imaging Spectrometer
(VIRTIS) instrument. "Although we were just calibrating VIRTIS during the
Earth fly-by last month, we obtained images of Earth and the Moon which
have a high scientific content."
Iani Chaos in False Color (Released 2 May 2005)
http://themis.la.asu.edu/zoom-20050502a.html
Iana Chaos - Another View in False Color (Released 3 May 2005)
http://themis.la.asu.edu/zoom-20050503a.html
Continuing Through Iani Chaos (Released 4 May 2005)
http://themis.la.asu.edu/zoom-20050504a.html
Ares Vallis/Iani Chaos Border (Released 5 May 2005)
http://themis.la.asu.edu/zoom-20050505a.html
White Rock in False Color (Released 6 May 2005)
http://themis.la.asu.edu/zoom-20050506a.html
All of the THEMIS images are archived at http://themis.la.asu.edu/latest.html.
NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission
for NASA's Office of Space Science, Washington, DC. The Thermal
Emission Imaging System (THEMIS) was developed by Arizona State
University, Tempe, in collaboration with Raytheon Santa Barbara Remote
Sensing. The THEMIS investigation is led by Dr. Philip Christensen at
Arizona State University. Lockheed Martin Astronautics, Denver, is the
prime contractor for the Odyssey project, and developed and built the orbiter.
Mission operations are conducted jointly from Lockheed Martin and from
JPL, a division of the California Institute of Technology in Pasadena.
EARTH AND MOON THROUGH ROSETTA'S EYES
ESA release
3 May 2005
ESA's comet chaser mission Rosetta took these infrared and visible images of
Earth and the Moon, during the Earth fly-by of 4/5 March 2005 while on its
way to Comet 67P/Churyumov-Gerasimenko. These images, now processed,
are part of the first scientific data obtained by Rosetta.
Rosetta’s VIRTIS instrument took this infrared view of the
Moon on 4 March 2005, before closest approach to Earth,
from a distance of 400 000 kilometers and with a resolution
of 100 kilometers per pixel. Red colors represent maria
regions, while blue regions are highlands. Image credit:
ESA.
This infrared image of Earth shows some examples of the
chemical components of our atmosphere that VIRTIS
detected. Areas of higher abundance of carbon dioxide are
shown in green. Image credit: ESA.
VIRTIS is a very powerful instrument capable of examining the physical
condition and composition of space objects. On 4 and 5 March, before closest
approach to Earth and from a distance of 400 000 kilometers from our Moon,
Rosetta's VIRTIS took these images with high resolution in visible and
infrared light. In these images, only a small portion of the Moon surface was
illuminated (between 19% and 32%).
These images show Earth in real colors (left) and stretched
false colors (right). The contrast between land, clouds and
sea has been increased. South America is seen in green
where, through the clouds, it is possible to distinguish (a)
Argentina and (b) the Andes mountain chains. The sea is
blue while the clouds have a reddish-yellowish tint. Image
credit: ESA.
This picture (left) is an image of the Moon in infrared light, with Sun's
illumination coming from the bottom left. In the first, VIRTIS is catching the
Marsbugs: The Electronic Astrobiology Newsletter, Volume 12, Number 17, 11 May 2005
thermal radiation coming uniformly from the lunar surface. In the second
VIRTIS is focusing on the solar radiation reflected by the surface. In the next
image (right) it is possible to distinguish Oceanus Procellarum, Kepler Crater
and Mare Humorum. The corresponding spectral analysis (chemical 'fingerprinting') gives indications of the mineralogical differences between highlands
and 'seas' or 'maria'. For instance, it was possible to see marked differences in
the abundance of two kinds of rocks known as pyroxene and olivine.
On 5 March, after the closest approach to Earth, VIRTIS then took a series of
high-resolution images of our planet in visible and infrared light from a
distance of 250,000 kilometers. Only 49% of the Earth surface was visible
from Rosetta. In this animation (right) of visible images, red, green and blue
colors are used to show a true-color Earth. The infrared images in the next
animation are taken in the so-called 'thermal' infrared, which shows the heat
emitted from Earth's surface. This animation shows the complex dynamics of
Earth's atmosphere.
Once at Comet 67P/Churyumov-Gerasimenko in 2014, VIRTIS will be used
to determine the composition and the nature of the solid nucleus and the gases
present in the comet's coma. In combination with the other Rosetta
instruments, it will also help the selection of the 'touchdown' site for the
Rosetta lander Philae.
Before then, Rosetta will make more cosmic loops to reach the comet, and its
instruments will collect new data about planets, asteroids and comets. The
next encounter with Earth is planned for November 2007.
VIRTIS as been developed by a large consortium of European scientists, with
major contribution by Italy, France and Germany.
Contact:
Angioletta Coradini, VIRTIS Principal Investigator
E-mail: [email protected]
Read the original news release at
http://www.esa.int/SPECIALS/Rosetta/SEMT4V2IU7E_0.html.
Additional articles on this subject are available at:
http://www.spacedaily.com/news/rosetta-05c.html
http://www.universetoday.com/am/publish/rosetta_earth_photo.html.
End Marsbugs, Volume 12, Number 17.
17