Download `A ship flying in space:` Earth seen through the eyes of an astronaut

‘A ship flying in space:’ Earth seen through the eyes of an astronaut
Posted on April 23 2012 by Matthew Knight, CNN
Italian astronaut, Paolo Nespoli captured a series of remarkable images of Earth during a sixmonth stay on the International Space Station.
As an estimated one billion people around the globe take part in events to mark the 42nd
Earth Day, Paolo Nespoli’s imagesprovide a striking reminder of our planet’s awe-inspiring
beauty and fragility as an eco-system.
During a six-month mission to the International Space Station (ISS) last year, the Italian
astronaut snapped around 26,000 images, posting daily updates on Twitter.
“I really tried to capture what I was seeing. I was amazed by the response from people. It was
very fulfilling for me. I was doing something which was very interesting for me, but it made
me more happy that I could share the images,” Nespoli said.
Nespoli explained to CNN what it’s like to see the world “turning around your feet” and the
unique perspective space travel provides on our planet and humans’ collective impact on it
.
Describe the view of Earth from space?
Paolo Nespoli:Â ”It’s a most unreal view you have from up there. It’s look as though it’s
painted. One of the things you gain up there is an appreciation of planet Earth as a kind of
ship. It looks like a ship flying in space.
The 55-year-old Italian (seen here on the left) with fellow crew members, Russian cosmonaut
Dmitry Kondratyev and NASA flight engineer, Cady Coleman.
“A lot of the time you’re up there you are working so you don’t have a lot of time to look out
of the window. When you do, most of the time you see oceans and clouds — which is really
nice.
“But it really takes a little bit of time before you acquire a perception of where you are and
what you are looking at and how to look at it in the best way.
“After a month, a month and a half, something strange happens — you look out of the
window and you know where you are. You might be over Australia, Africa, you just know.
It’s amazing how you just develop this.”
How high does the ISS orbit?
PN:Â We are 400 kilometers (248 miles) above the Earth and fly at a velocity of 20,000
kilometers-per-hour (12,400 mph) — the equivalent of about 7.7 kilometers-per-second (4.8
miles-per-second).
How did traveling to space change your outlook on Earth?
PN:Â ”I felt like a human being, a terrestrial guy — not an Italian or a European. I felt like
an earthling.
Nespoli posted regular updates on Twitter. "I was amazed by the response from people. It
was very fulfilling for me," he said.
“You get an appreciation of how delicate the planet is. You see the atmosphere which covers
the Earth like a blanket. It looked like if I would blow on it too hard it would float away. We
know if that get’s corrupted in a certain way that’s the end.”
How do you think humans are affecting the planet?
PN:Â ”The impact we are having on this planet is surely microscopic when we look at one
single event, but when you look at it and you repeat these events all over – a few miles across
here, a few miles across there, a river here, a river there, a city here, a city there — and it’s
clear we are a major force in shaping the crust of this planet and its clear we have the
capability of imparting changes.
“I cannot say we are bad, or that we are causing the planet to go hot or cold. We don’t have
enough data. But it’s clear that we are doing things that have a huge
potential of making changes. We need to
understand more. It’s a risky situation with a very delicate eco-system balance which can be
dramatically skewed.”
Thoughts on the future of space travel?
PN:Â ”I think space travel will become successful as a tourism activity. I wish everybody
could go up there and see the world from a different point of view, with different eyes.
“I would, for sure, send up the politicians (some of them we should leave there!) to change
the way they think, but I would also send up philosophers, journalists and theologians.”
Two new Earths and the search for life
Posted on December 26 2011 by elly
Editor’s note:Â Meg Urry is the Israel Munson professor of physics and astronomy and
chairwoman of the department of physics at Yale University, where she is the director of
Meg Urry
the Yale Center for Astronomy and Astrophysics. This article was written in association
with The Op-Ed Project.
New Haven, Connecticut (CNN)Â – Americans were enthralled by fake reports of an alien
invasion in the Orson Welles “War of the Worlds” radio broadcast on Halloween Eve in
1938. Hundreds of science fiction movies from the 1902 silent epic “A Trip to the Moon”
(featured in the current film “Hugo”) to “Star Wars” to this year’s “Cowboys and Aliens”
have fed a deep curiosity about intelligent beings elsewhere in the universe.
Hang on to your hats, because reality is starting to catch up.
On Tuesday, scientists reported evidence from the Kepler satellite that two Earth-sized
planets are orbiting a nearby star about 1,000 light years from earth — practically our back
yard compared to the extent of our Milky Galaxy, but far too distant to visit with current
spacecraft.
These planets, named Kepler 20-e and Kepler 20-f, have sizes and masses similar to the
Earth, and their host star is similar to our sun. But the resemblance ends there. Both orbit very
rapidly — in 6.1 days and 19.6 days, respectively, compared to 365 days for an Earth year —
so both are much closer to their star than the Earth is to the sun.
This makes both planets way too hot to support life as we know it. Still, the pace of planet
discovery is astonishing. Sometime in the next few years, scientists will likely discover
Earth-like planets that are capable of supporting life.
Our sun is just one star among the hundreds of billions that make up the Milky Way galaxy,
which itself is only one of hundreds of billions of galaxies in the universe. Over the last 15
years, astronomers have found hundreds of planets orbiting stars in our corner of the Milky
Way and the list will pass 1,000 next year.
Planets are plentiful. Discoveries of planets are limited only by the capabilities of current
telescopes and instruments and by the time needed to sample several full orbits of a planet
around its host star.
Most “extra-solar planets” (or “exoplanets”) have been found by measuring tiny Doppler
shifts (wavelength shifts) in the light of the host star. With this method it is easier to find
heavy planets than light ones, and easier to find planets in close rather than distant orbits. So
most of the planets found so far are big ones, similar to Jupiter or Neptune in our solar
system, only orbiting much, much closer than the Earth to their host star. This is kind of like
surveying your neighborhood for sumo wrestlers: You find far fewer than the number of
other people who live there, and way fewer than the population of the world. So the 716
known exoplanets are just the tip of the iceberg.
The Kepler satellite uses a different method, based on transits of planets across the face of
their host star. Visible light from the star dims very slightly, typically by 0.01% or less for an
Earth-sized planet passing in front. Thus Kepler finds planets regardless of mass, although it
more easily sees large planets (which cover more of the star’s surface and thus diminish the
light more) and it only sees planets that cross the star as seen from the Earth (which most
planets don’t).
By the way, you can help make these discoveries. Atwww.planethunters.org, a citizen science
project started by colleagues of mine at Yale, anyone can search the Kepler data for signs of
new planets. In particular, users might find unusual systems that the Kepler computer
algorithms don’t search for. (For a fun Christmas holiday interpretation of the Kepler plots of
star brightness over time, see this video.)
“Life” can mean anything from single-celled organisms to a walking, talking homo sapiens,
or possibly something much stranger. For now, scientists are focusing on conventional
carbon-based life because its signatures are well known.
Such life requires liquid water, meaning a temperature between freezing (32 F) and boiling
(212 F). Planets too close to their star will be too hot, like the sweltering surface of Venus,
which approaches the 800 degree Fahrenheit temperature of Kepler 20-f. Planets too far away
have frigid surfaces, like Europa, a moon of Jupiter.
Temperatures that allow water to be liquid define the so-called “habitable zone” — like
Goldilocks’ favorite porridge, planets in the habitable zone are not too hot, not too cold, but
just right for life.
We haven’t yet found definitive signs of life elsewhere in the universe. But we can estimate
that even the narrowest case of carbon-based life on an Earth-like planet orbiting a sun-like
star in the habitable zone is likely, because planets are probably common around such stars,
sun-like stars are common in our galaxy, and our galaxy is similar to many throughout the
universe.
We also know the building blocks of life — amino acids and other organic compounds —
form naturally from carbon, water and energy, as the chemists Stanley Miller and Harold
Urey first showed more than 50 years ago.
Sadly, although life is likely to exist on exoplanets throughout our Milky Way galaxy,
intelligent life is another thing altogether. Humans have lived at most a few hundred thousand
years out of the Earth’s 4.6 billion year history — or less than 0.006% of the available time.
In contrast, simple single-celled organisms probably formed several billion years ago, and
thus have populated the Earth for more than three-quarters of its existence. This means it is
overwhelmingly likely that the life we find elsewhere will be extremely primitive.
Face it: We’re not going to be IM’ing with aliens, nor should we expect an invasion or a
rendezvous in outer space.
For now, we’re just looking for cells breathing and multiplying. Not “Another Earth” —
more like “The Blob” (or, “The Green Slime”).
The mystery of the Higgs boson
Posted on January 10 2012 by Renee Lewis / Al Jazeera
Two experiments at CERN could confirm or
contradict everything scientists theorise about the nature of the universe.
When you stare into the night sky, the planets, stars and galaxies you can see make up only a
tiny four per cent of what’s actually out there.
That’s according to scientists who work in laboratories with particle accelerators to find out
more about the rest. What’s more, two exciting experiments being carried out right now could
confirm or contradict everything scientists believe they know about the nature of the
universe.
First, the search for the Higgs boson particle, which could unlock secrets about the beginning
of the universe, and secondly, the Opera experiment – in which certain particles appeared to
travel faster than the speed of light – which is believed to be the limit of speed.
If the results from the Opera experiment are reproducible, it would mean a correction to
Einstein’s theory of special relativity, proposed in 1905.
And physicists at CERN in Switzerland have recently announced that they may be closing
in on a sighting of the Higgs boson particle – which would tell researchers about the origin of
particle mass and shed light on the process of the creation of the universe.
Earth’s twin discovered beyond solar system
Posted on December 6 2011 by Aljazeera / IM
A NASA team has found a small planet best positioned to have liquid water but has yet to
determine whether it is solid.
The most Earth-like planet ever discovered is circling a star 600 light years away, a key
finding in an ongoing quest to learn if life exists beyond Earth, scientists have said.
The planet, called Kepler-22b, joins a list of more than 500 planets found to orbit stars
beyond our solar system. It is the smallest and the best positioned to have liquid water on its
surface — among the ingredients necessary for life on Earth.
“We are homing in on the true Earth-sized, habitable planets,” said San Jose State University
astronomer Natalie Batalha on Monday.
Batalha is the deputy science team leader for NASA’s Kepler Space Telescope,
which discovered the star.
The telescope, which was launched three years ago, is staring at about 150,000 stars in the
constellations Cygnus and
Lyra, looking for faint and periodic dimming as any circling planets pass by, relative to
Kepler’s line of sight.
Results will be extrapolated to determine the percentage of stars in the Milky Way galaxy
that harbour potentially habitable, Earth-size planets.
This is the first detection of a potentially habitable world orbiting a Sun-like star, scientists
reported in findings to be published in The Astrophysical Journal.
Kepler-22b is 600 light years or roughly 6 trillion miles away.
Ground telescopes
Planets about the same distance from their parent stars as Earth take roughly a year to
complete an orbit. Scientists want to see at least three transits to be able to rule out other
explanations for fluctuations in a star’s light, such as small
companion stars.
Results also are verified by ground and other space telescopes.
Kepler-22b, which is about 2.4 times the radius of Earth, sits squarely in its star’s so-called
“habitable zone,” the
region where liquid water could exist on the surface. Follow-up studies are under way to
determine if the planet is solid, like Earth, or more gaseous like Neptune.
“We don’t know anything about the planets between Earth-size and Neptune-size because in
our solar system we have
no examples of such planets. We don’t know what fraction are going to be rocky, what
fraction are going to be water worlds, what fraction are ice worlds. We have no idea until we
measure one and see,” Batalha said at a news conference at NASA Ames Research Center in
Moffet Field, California.
If Kepler-22b has a surface and a cushion of atmosphere similar to Earth’s, it would be about
22 degrees Celsius, about the same as a spring day in Earth’s temperate zone. Among the
2,326 candidate planets found by the Kepler team, 10 are roughly Earth-size and reside in
their host stars’ habitable zones.
Another team of privately funded astronomers is scanning the target stars for non-naturally
occurring radio signals,
part of a project known as SETI, or the Search for Extraterrestrial Intelligence.
“As soon as we find a different, a separate, an independent example of life somewhere else,
we’re going to know that it’s
ubiquitous throughout the universe,” said astronomer Jill Tarter, director of the SETI Institute
in Mountain View.
The Kepler team is meeting for its first science conference this week.
"Mata Semesta" Tertangkap Kamera
Penulis : Yunanto Wiji Utomo | Minggu, 7 Oktober 2012 | 13:45 WIB
NASA Nebula Helix (NGC 7293), nebula planet yang berjarak 650 tahun cahaya dari Bumi
di konstelasi Aquarius.
CALIFORNIA, KOMPAS.com — Teleskop Badan Penerbangan dan Antariksa NASA
menangkap citra Nebula Helix (NGC 7293). Dalam citra NASA, nebula tersebut tampak
seperti mata alam semesta.
Citra tersebut dirilis NASA pada Rabu (3/12/2012), dihasilkan dari pengamatan Spizer Space
Telescope yang mengobservasi langit dalam cahaya inframerah dan Galaxy Evolution
Explorer (GALEX) yang mengobservasi dalam gelombang ultraviolet.
"Mata semesta" tersebut sejatinya menunjukkan bintang sekarat atau nebula planet. Citra
Nebula Helix yang berjarak 650 tahun cahaya dari Bumi itu mencerminkan apa yang akan
terjadi pada Matahari 5 miliar tahun lagi.
Nebula planet adalah bintang seukuran Matahari yang memasuki masa akhir hidupnya.
Nebula ini kehilangan hidrogen dan helium yang menjadi bahan bakar reaksi fusi. Di tahap
ini, bintang melepaskan gas di permukaannya dan akhirnya terkondensasi menjadi bintang
katai putih.
"Bintang katai putih itu kurang lebih seukuran Bumi namun massanya seperti massa bintang
pada mulanya. Faktanya, satu sendok teh materi bintang katai putih punya massa sama
dengan gajah," tulis NASA di situs webnya seperti dikutip Space, Jumat (5/10/2012).
Dalam citra di atas, bintang katai putih tampak sebagai bintik putih di tengah nebula. Bintang
katai putih itu mengemisikan radiasi ultraviolet. Dalam foto hasil observasi GALEX, radiasi
ditampilkan dalam cahaya biru sementara dalam hasil observasi Spitzer tampak sebagai
cahaya kuning.
Nebula planet sama sekali tak ada hubungannya dengan planet. Dinamai nebula planet sebab
adanya kesalahan observasi pada abad ke-18, di mana nebula planet dikira planet gas raksasa.
Nama tetap dipertahankan hingga kini.
Editor :
yunan