Imagine
yourself driving on an empty straight road. Because there is no one
around, you have pushed the accelerator pedal little harsher than the
usual and the ride is pretty enjoyable. Suddenly you see a huge sized
something; on the horizon, rumbling towards you. You naturally slow
down and as that thing approaches, you realise that is is a giant
howling bulldozer slowly creeping on the road with its monstrous
front loader bucket directly pointed towards you. What would you do?
I would certainly stop the car on the curb and let that thing pass.
Only then, with a sigh of relief, I would press on with my journey.
If I
tell you that similar scenario is taking place in deep space, would
you believe it? Probably not; but believe me that this is what
exactly is happening to India's Mars Orbiter spacecraft, as it was
merrily clicking its camera, while going around the red planet.
This
week, planet Mars is expecting an unusual visitor. The skies over it
will be graced by an unforgettable and spectacular sight. A comet
called as Siding Spring and identified as Comet C/2013 A1, is going
to have an extremely close passage by the planet. Sliding spring was
the first comet discovered in 2013 and was spotted by veteran comet
hunter Robert McNaught from the Siding Spring Observatory in
Australia. Normally dozens of comets are discovered in any given
year. However, this one really caught the attention of astronomers
because it was perceived to hit Mars in October 2014. Later
observations and recalculations ruled out this event, but it is still
expected to speed past the red planet at a real close distance of
87,000 miles (139,500 kilometres) from the center of Mars. This fly
past is predicted to happen on Sunday, October 19th,
at 18:27 Universal Time (UT) or around midnight IST.
What
India's Mars orbiter camera would see if it turned towards the comet?
Here are some facts that are stunningly spectacular. The nucleus of
A1 Siding Spring is thought to be 700 meters across, its Coma or the
nebulous envelope around the nucleus, extends 19,300 km in diameter.
The comet’s closest passage is just under six times the distance of
Mars’ outer moon Deimos, and at closest approach, the coma will
appear almost 8 degrees in size to any would be Martian — that’s
16 times the diameter of a Full Moon as seen from the Earth — and
will be crossing the skies at a staggering 1.5 degrees a minute.
Mars Orbiter can easily see the motion of the comet as it moves
across the Martian sky. The Comet has an enormous tail that would
also span the sky.
U.S.
space agency NASA says, that Comet Siding Spring has travelled many
billions of miles and would come within about 87,000 miles of Mars on
October 19. The comet comes from the Oort Cloud, material left over
from the formation of the solar system.
At
present, there are three spacecraft circling Mars. These include
NASA'a MAVIN, European MARS EXPRESS and Indian Mars Orbiter MOM. All
have taken steps to shield their spacecrafts from any damage from
Comet's tail. Mr. Kiran Kumar, Director of ISRO’s Space
Application Centre, says that they have altered MOM’s orbit so as
to move it behind the Red Planet when the comet arrives. In September
2014, When inserted in Martian orbit, MOM circled Mars in an orbit
that was 423 by 80,000 kilometers. To make changes in this orbit,
the spacecraft consumed 1.9 kilograms of fuel.
At the
comet's closest approach, MOM will be 400 kilometers away from the
surface of the Red Planet on the opposite side from the comet. Kiran
Kumar says that MOM’s highest altitude is currently 72,000
kilometers, which is expected to remain unchanged even after the
departure of the comet. The minimum distance between MOM and the
comet on October 19 will be around 140,000 kilometers. According to
him the comet will have no negative impact on the future performance
of the spacecraft or its science mission.
Mr.
Kumar says that MOM will carry out observations of the comet and its
Mars Colour Camera will click images of it. ISRO's chairman,
K.Radhakrishnan, had stated earlier that the arrival of the comet
will be viewed as an opportunity for doing scientific observations.
ISRO and NASA scientists will collaborate in analyzing data generated
by MOM and MAVEN related to the Comet Siding Spring.
Meanwhile,
giving this spectacular event, a human touch, ISRO has tweeted;
“Joining
the welcome party for comet #SidingSpring. @MarsCuriosity,
@MAVEN2Mars, @HiRISE, #MarsOdyssey & #MarsExpress are there too.
Excited!”
What
can I say after this? Well! Dear MOM, enjoy the party.
18th
October 2014
p.s.
The comet has come and gone. Most important thing is that MOM is safe and sound, as can be seen from this tweet from ISRO's Mars Orbiter
p.s.
The comet has come and gone. Most important thing is that MOM is safe and sound, as can be seen from this tweet from ISRO's Mars Orbiter
20th October 2014
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