Download Volume 1 (Issue 3), March 2012

SUPARCO - ASTRONOMY & ASTROPHYSICS
BULLETIN
Volume I, Issue 3
Pakistan Space Vision 2040, was
approved by the Prime Minister of
Pakistan which inter-alia included
augmentation / strengthening of
the Astronomy and Astrophysics
programmes of SUPARCO.
SUPARCO`s
astronomy
and
astrophysics program is mainly
focused on theoretical and
observation research. For this an
astronomical
observatory
is
planned to be established.
Research studies pertaining to
deep space objects including
galaxies, nebulae and variable
stars are also being initiated.
Search for earth like planets is a
hot
topic
in
astrophysics
nowadays. It is planned to conduct
research studies in this field also.
Inside this Issue:
March, 2012
Cycles of the Sun, Earth and Planets
Our Sun, the nearest star, rises and sets every day. This motion of the Sun in
the sky occurs because of the rotation of the Earth on its axis. The Earth
completes one rotation in 24 hours and takes approximately 365.25 days to
complete one revolution around the Sun, which is called a year. Rotation is
the turning of a body on its axis, whereas a revolution means the motion
around a point outside the body.
Our sky is always filled with stars even in daytime. It is glare of the Sun which
makes them invisible during daytime. If it would be possible to see stars in
daytime, then the daily observation of the Sun would allow us to see that the
Sun appears to drift in the sky against the background of stars. Factually this
slow drifting of the Sun in the sky is due to the Earth’s motion in its orbit. The
Earth moves at an average speed of 30 km/s in its orbit and at a distance of
around 149.6 million km from the Sun. Due to this daily drifting, the Sun
appears to move over a path, known as Ecliptic. In other words ecliptic is the
projection of the Earth’s orbit in the sky. Furthermore, it appears that the sun
completes one revolution per year by moving in front of different
constellations, named as Zodiac Constellations. This apparent motion of the
Sun has an important effect as it creates seasons on the Earth.
Cycles of the Sun,
Earth and Planets
Software Review
Sky this Month
& Events
Sun Spots
Ec
Ecliptic
Book Review
lip
tic
Web Review
Magentic Stroms
Monitored by SUPARCO
Venus, Our Sister Planet
Events of Month
Date
Time
Event\Direction
03 Mar
After Sunset
Mars in opposition \ East
05 Mar
7:30
Murcury conjuct
Uranus \ West
14 Mar
After Sunset
Conjuction of
Venus & Jupiter \ West
26 Mar
After Sunset
Moon, Jupiter & Venus
together with new moon
Seasons arise because of the simple fact that the Earth is tilted on its axis and
this tilt is about 23.5 degrees. Both the axial tilt and the Earth’s motion around
the Sun create seasons on the Earth. There is a misconception that seasons
arise as the Earth move near and far from the Sun and in its orbit. However
seasons occur because the Earth receives different amount of light during
different times of the year. For example during summer season, position of
the Earth and the Sun is such that the sun rays fall vertically on the Earth so
that per unit area on the Earth receives more light which increases the surface
temperature.
SUPARCO - ASTRONOMY & ASTROPHYSICS Bulletin is a monthly publication
Page II
Cycles of the Sun, Earth and Planets
There is another interesting fact that is when
there is summer in Northern hemisphere there is
winter in Southern hemisphere and vice versa.
On the day of the summer solstice (longest day)
in late June, Earth’s Northern hemisphere is
inclined toward the Sun (Fig 1) and sunlight
shines almost straight down at Northern
latitudes. At Southern latitudes, sunlight strikes
the ground at an angle and spreads out.
Similarly on the day of the winter solstice
(shortest day) in late December, Earth’s
Northern hemisphere is inclined away from the
sun, and sunlight strikes the ground at an angle
and spreads out (Fig 2). At Southern latitudes,
sunlight shines almost straight down and does
not spread out, hence the situation reverses.
Fig 1
Fig 2
The planets of our solar system produce no
visible light of their own; they are visible only by
the reflected sunlight. Mercury, Venus, Mars,
Jupiter, and Saturn are all easily visible to the
naked eye and look like stars. If the solar system
is seen from North celestial pole, it would seem
that the planets are moving in the same
counterclockwise direction in their orbits, with
the planets farthest from the sun moving the
slowest. Planets are always seen near the
ecliptic in the sky because their orbits lie in
nearly the same plane. The planet, whose orbits
SUPARCO - ASTRONOMY & ASTROPHYSICS Bulletin is a monthly publication
lie outside the orbit of Earth, move slowly eastward
along the ecliptic. Mars moves completely around
the ecliptic in slightly less than 2 years, but Saturn,
being farther from the Sun, takes nearly 30 years.
Mercury and Venus also stay near the ecliptic, but
they move differently from the other planets
because they have their orbit inside the orbit of
Earth. This means they never move far from the
Sun in the sky. As seen from Earth, they move
eastward away from the Sun and then back toward
the Sun, when they are at their closest approach to
the Sun.
.
.
To find one of these planets, look above the
western horizon after sunset or above the eastern
horizon before sunrise. Venus is easier to locate
because it is brighter and also its larger orbit
carries it higher above the horizon than Mercury.
Page III
Software Review
WorldWide Telescope
Developed by Microsoft, WorldWide Telescope
(WWT) is virtual astronomy software which
displays the astronomical sky as maps. Users are
able to pan around outer space and zoom as far
into any one area as the data will allow. It is
possible to view the sky in many wavelengths of
light. The software utilizes Microsoft's Visual
Experience Engine technologies to function. The
program is designed to scale from web browser to
desktop, to large multi-channel full dome digital
planetarium. The WWT project began in 2002 at
Microsoft Research and Johns Hopkins
University and it was announced at the TED
Conference in Monterey, California in February
2008.
WorldWide Telescope has five main modes.
These are Sky, Earth, Planets, Panoramas, and
Solar System.
Sky mode is the main feature of the software. It
allows users to view high quality images of outer
space, with images from various space and
earth-based telescopes. Each image is shown at
its actual position in the sky. There are over 200
full-sky images in spectral bands ranging from
radio to gamma. Earth mode allows users to view
a 3D model of the Earth, similar to NASA World
Wind, Microsoft Virtual Earth and Google Earth.
SUPARCO - ASTRONOMY & ASTROPHYSICS Bulletin is a monthly publication
Planets mode currently allows users to view 3D
models of eight celestial bodies: Venus, Mars,
Jupiter, four of Jupiter's larger moons, and our own
planet's Moon. The Panorama mode allows users to
view several Mars Rover panoramas. Solar system
mode displays the major solar system objects from
the Sun to Pluto, and Jupiter's moons, orbits of all
solar system moons, all 550,000+ minor planets
positioned with their correct scale, position and
phase. The user can move forward and backward in
time at various rates, or type in a time and date for
which to view the positions of the planets, and can
select viewing location. The program can show the
Solar System the way it would look from any
location at any time between 1AD and 4000AD.
Using this tool a user can watch eclipse, occultation,
or astronomical alignment, and preview where the
best spot might be to observe a future event. In this
mode it is possible to zoom away from the Solar
System, through the Milky Way, and out into the
cosmos to see a hypothetical view of the entire
known universe. Other bodies, spacecraft and
orbital reference frames can be added and
visualized in the Solar System Mode using the layer
manager.
This software has received awards like AIGA Annual
Design Competition for the experience design
category and I.D. Magazine 2009 Annual Design
Review for interactive category.
Page IV
Web Review
http://www.starchild.gsfc.nasa.gov
The website under review for the month of March is
www.starchild.gsfc.nasa.gov. This website is a
service of High Energy Astrophysics Science
Archive Research Center (HEASARC), within the
Astrophysics Science Division (ASD) at NASA /
GSFC.
As its name depict, this website is solely designed
keeping in mind of kid’s level astronomy. The
website starts with a page welcoming young
astronomers. This website has been developed
primarily by a duo of middle school teachers who
generously volunteered their time and talents for
making this website.
StarChild has two sections namely level 1 and level
2 for astronomy material. Information on each
section is primarily devoted to the students of
different grade levels. The pattern of information is
same but additional information is given in the level
two of the website. Each page then goes on further
with other useful links to the related information.
For school teachers there is a link given on the
main page describing the usage with instructions
and guidance for the material available on the
website. This website is very useful resource for
teachers teaching astronomy at primary level.
SUPARCO - ASTRONOMY & ASTROPHYSICS Bulletin is a monthly publication
Book Review
The Photographic Atlas of the Moon published by
Cambridge University press is a day-by-day
photographic guide to observe the features of the
Moon through a small telescope. This book is
compiled by three amateur astronomers S.M.
Chong, Albert Lim and P.S. Ang. All the pictures in
the book are taken by using 40 cm telescope and a
high resolution low speed film. Whole Moon images
are provided for each day of 29-day lunar cycle,
with labeled features and accompanying
descriptive text. Selected lunar features are shown
at high magnification to highlight and illustrate
certain regions. All lunar features are labeled using
current IAU terminologies. A comprehensive set of
appendices provide the details about the phases of
the Moon and index of all lunar features named in
the text. This book is an invaluable guide book for
those who are interested in lunar observation with
small telescope.
Starting with the conjunction, the book goes on
explaining daily increment in moonshine at lunar
surface with details of features thus visible at that
time. Each day photograph is also shown with the
details of instruments used to take the photograph.
Photographic atlas of the Moon can be used as a
quick reference guide for daily moon appearance in
the sky. Having this book with the small telescope
or binocular one can explore the detailed features
of the Moon.
Page V
Sky this Month
March 3, 2012 – Mars in opposition
Mars will be closest to Earth and its surface will be
fully illuminated by the Sun. This view will be
visible in the eastern direction after sunset. This is
the best time to view and photograph Mars.
March 5, 2012 - Mercury conjunct Uranus
Mercury and Uranus will be in conjunction with
each other in the sky, in western direction.
March 20, 2012 - Equinox of March
March Equinox occurs at 05:14 UT. The Sun will
shine directly on the equator and the days and
nights will be almost equal in the whole world. This
is also the first day of spring (spring equinox) in the
northern hemisphere and the first day of fall
(autumnal equinox), in the southern hemisphere.
March 22, 2012 - New Moon
Moon will be directly between Earth and Sun and
will not be visible from Earth. This phase takes
place at 14:37 UT. Chances of new moon will be
next day.
March 26, 2012 - Moon, Jupiter and Venus
together with New moon
New moon will be between the two brightest
planets, Venus and Jupiter. It’s a nice time to see
the top three brightest object of the night sky
together in the same section of the sky. Although
the sequence of the objects will be Jupiter, the third
brightest; Moon, the brightest and then Venus, the
second brightest object as seen from the horizon.
This view will be visible in the west direction after
sunset.
March 8, 2012 - Full Moon
Earth will be between the Sun and Moon, and
therefore, the Moon will be fully illuminated as seen
from Earth.
March 14, 2012 - Conjunction of Venus and
Jupiter
The two bright planets will appear 3 degrees apart
from each other in the sky in the west direction.
SUPARCO - ASTRONOMY & ASTROPHYSICS Bulletin is a monthly publication
Page VI
Sunspots
Sun which is the most common object we see in
day has dark spots on it known as sunspots.
These spots could easily be seen through any
small telescope but during a foggy day it is a
great opportunity to view bigger ones. Sunspots
have always been mysterious for human beings
and without these spots on it; Sun would rather
be a boring star! The human observation of
sunspots is very old and their written record
exists since Greek times. Sunspots occur in
groups as well as individuals, and their number
varies from minimum value to maximum
following an 11 year cycle known as sunspot
cycle. When sunspots are very small in number
it is called Solar Minimum, and when they reach
to their maximum numbers it is called Solar
Maximum. Although sunspots appear dark but
still have temperature about 3800 Kelvin as
these are relatively cooler regions of solar
surface and the average surface temperature of
the sun is about 6000 K.
Image of the sunspot taken by SUPARCO
on Feb 23, 2012
Since we can only view one side of the Sun therefore
to calculate sunspots over the whole surface of the
Sun is to be observed for one month because it takes
about 27 days for Sun to complete one complete
rotation around its axis.
Image of the Sun taken by SUPARCO on
Feb 23, 2012
The sunspots appear very small as the Sun is
very far from us but actually they could be larger
than Earth. Sunspots are produced due to
magnetic fields which are twisted like rubber
band coming out of the photosphere; the outer
most layer of the Sun appearing yellow as we
see in noon time. These fields have roots in the
convection zone (the region below photosphere)
and generated due to charge particle motion.
SUPARCO - ASTRONOMY & ASTROPHYSICS Bulletin is a monthly publication
View of Sunspots showing Umbral (central dark
region) and Penumbral (less darker region)
surrounded by granulated surface of the Sun.
Page VII
Magentic Stroms Monitored by SUPARCO
The Space Weather Monitoring Facilities at SUPARCO recorded magnetic storms during Feb. 14-15,
2012 due a Coronal Mass Ejection which erupted on Feb. 9, 2012. The following magnetograms show
disturbances recorded by the Abdus Salam Geomagnetic Observatory at Sonmiani.
The magnetograms show the disturbed magnetic field, recorded by the Abdus Salam Geomagnetic Observatory at Sonmiani
A similar magnetic disturbance was recorded during Feb. 18-22 caused by an Earth-facing Coronal
Hole as shown in the magnetograms below.
This magnetogram shows disturbance from an earth facing Coronal Hole sending out highspeed solar wind particles
starting from late hours of Feb. 18, 2012
The dark area shown in this image taken by
GOES-15 satellite’s Solar X-ray Imager
(SXI) shows the Coronal Hole CH501 which
caused the magnetic disturbance
SUPARCO - ASTRONOMY & ASTROPHYSICS Bulletin is a monthly publication
Image taken by NASA’s Solar Dynamics
Observatory (SDO) shows a magnetic
filament erupting
Page VIII
Venus: Our sister planet
Venus is the second planet of the solar system and closest in size to the Earth. Diameter of Venus is
only 650 km smaller than the diameter of Earth and it comes within 40 million km of the Earth, nearer
than any other planet. It is the brightest object in the sky after the Sun and Moon. The brightness of
Venus is because of two reasons; firstly it is closest to us than any other planet and secondly it is
entirely covered with thick clouds. These clouds reflect sunlight very effciently even the surface of
Venus is not visible through optical telescopes.
Venus can be seen in the morning or evening, depending on it position, whether it lies to the west or
east of the Sun. These days Venus can be spotted in the western direction. Like our Moon, Venus goes
through phases and a small telescope or binocular can easily show these phases.
Simulated view of Venus
Phase of the Venus shown by software on Jan
19, 2011
Telescopic view of Venus:
Image of Venus taken by SUPARCO,
through telescope on Jan. 19, 2011
Jupiter
Naked Eye view
Contact Information
Venus is always close to the Sun in the sky usually
appearing near the horizon in the twilight. Its brilliance
makes it easy to distinguish from adjacent stars. In this
picture, taken by SUPARCO on Feb. 23, 2012 Venus is
visible in the western sky, another bright point in the
figure is Jupiter.
Venus
Rizla Zareen
General Manager
Gulzar-e-Hijri SUPARCO Road
Sector 28, SUPARCO, Karachi, Pakistan
Tel: 021-34690765-74
Fax 021-34690795
Email: [email protected]
SUPARCO - ASTRONOMY & ASTROPHYSICS Bulletin is a monthly publication
This bulliten can be downloaded from the official website of SUPARCO