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STAR GAZING CLUB NEWSLETTER! AUGUST 2011
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Though too small to earn the distinction of planet,asteroids and
comets strike huge fear in the humanmind. And for good reason: at
some point in the future,one of the chunky rocks or icy mud balls
will slam into
Earth and alter the course of history. Such an impact 65mya is
widely believed to have killed offthe dinosaurs.
One of the most well-known and intriguingtheories suggested for
dinosaur extinction is The
Asteroid Theory. It is suggested that a huge asteroid orcomet,
perhaps miles in diameter, hit the Earth endingthe existence of
almost 50% of the earths species.
A crater, now worn down and partly under theocean, was found
along the Mexican Yucatan Peninsula.The Yucatan crater or the
Chicxulub Crater, as it iscalled today was formed by an impact of
an asteroidthat was roughly 10 km in diameter that hit with
100million megatons of force. That is equivalent to all ofthe
nuclear bombs in existence today.
Scientists at the Southwest Research Institute inBoulder,
Colorado, have even been able to trace thepath of that asteroid
back into space. According totheir calculations 160 million years
ago a collisionbetween a 100-mile-wide asteroid, named Baptistina
,and a smaller unnamed asteroid out beyond the orbit ofMars,
shattered the larger object and sent pieces of itinto the inner
solar system. Ninety-five million years
after that, these pieces encountered earth - ending
thedinosaurs!
Though alternate theories for the sudden climaticchanges have
been proposed, the significance of theYucatan crater cannot be
ignored. It changed the faceof evolution in one mighty stroke. Can
you imaginewhat would happen if something like that
occurredtoday?
ROGUE REMNANTS
Just in case: HOW TO DEFLECTA ROGUE ASTEROID?Scientists have
come up with a number of differ-ent ways of deflecting an incoming
asteroid fromits path, some more realistic than others. Hereare a
few of the best ideas:
1. Nuclear blast: A large nuclear explosion on anasteroid might
be enough to deflect an asteroidbut has significant political and
ethical problems.
And what if we just blew it into smaller pieces?
2. Using mirrors: A fleet of spacecraft carryinglight-reflecting
mirrors might be able to vaporizethe asteroid's surface using the
Sun's rays. The
gases from its surface would create a tiny amountof thrust -
enough to divert it
3. Gravity tractor: Crashing a spacecraft int theasteroid's
surface would certainly be the cheapestoption. The ship's own tiny
gravity would thenhelp move the asteroid's path. But this
option
would take a long time to make a difference
The Chicxulub Crater along the Mexican Yuacatan Penin-
sula created by a 10 km wide asteroid, probably wiping of
Dinosaurs 65 mya.
Earth has been attacked by big, rogue asteroids on nearly 20
occasions in the last 50 years. But, both Earth and man-
kind, have been saved every single time, courtesy - our
Hollywood directors! In the real world, however, the
probability
of getting hit (or even nearly hit) by an asteroid of severe
consequences (diameter > 1km) is Once in 500,000 years!
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STAR GAZING CLUB NEWSLETTER! AUGUST 2011
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Any Dan Brown fan will be familiar with thistheory: Life was
planted on earth &om outer space. Afterthe futile attempt to
prove this theory in DeceptionPoint, NASA scientists may have found
somethingmore promising.
Earth, when it formed billions of years ago was
dry, scientists say. So where did the water come from?One
possible theory is from crashing comets (that areessentially icy
snowballs). But comets come from theouter reaches of the solar
system tend to have moreheavy hydrogen than the water in our
oceans.
Recently, scientists found lots of life-essentialwater frozen as
ice in an unexpected place in oursolar system: asteroids between
Mars and Jupiter.
These asteroids might have the right heavy hydrogenratio to
match what's on Earth.
Furthermore, scientists didn't just find ice; theyfound hydrogen
and oxygen molecules locked in clay,and also organic molecules,
similar to what may havestarted life on Earth. These asteroids hold
clues not
only to our past and how the solar system and wateron Earth may
have originated but also have cluesabout our future with
exploration of near-Earthasteroids and may even be a possible
intermediatebase for deep-space ventures.
In conclusion we can say if this theory is proven,the search for
extraterrestrial lives ends in our ownbackyard. We are the
aliens!
Four gigantic telescopes around the world tire-lessly stare at
the sky, taking three images for everyregion of the sky. The
International Asteroid SearchCampaign (IASC) has made a public
outreach pro-
gram to use these images to discover asteroids. It is
acollaboration of universities and institutions spreadover 11
countries, and Star Gazing Club, NITK is apart of it.
Over this summer, five members of the Star Gaz-ing Club analyzed
a large number of image sets andobserved asteroids.
An open source software called Astrometricaproved to be very
useful in the the search for aster-oids. It has inbuilt image
processing tools such asTracking, Stacking, and Blinking. It also
has a feature
of Known object overlay with a huge database of up-
to-date asteroid and star locations.
The software makes use of the fact that asteroidsapparently move
less, as they are closer than stars.Stack aligns the stars and
thus, asteroids look longand blurred. Track aligns moving objects
thus, making
them sharp and bright. And then the motion of aster-oids can be
distinctly seen through the Blinking Util-ity. Once an object is
identified as a probable aster-oid, it is sent over the internet,
to be checked andverified by professional astronomers. If the
trackedobject doesnt show up in any existing databases, thena new
asteroid is discovered!
Even though a new asteroid wasnt discoveredduring the search
this summer, it was an incrediblelearning experience for SGC
members, who got tohandle real data and work along with
professionals.SGC looks forward to participate in it again,
some-
time soon.
HOW DO WEFIND/DISCOVER ASTEROIDS?
SGC Astro-Quiz, 16th August, Tuesday, 6 pm at the MSH. Contact:
Cambodge, 9008419372
THE
LIGHTERSIDE:
End Note: WE ARE THE ALIENS!
