February 26, 2013

A Slight Chance of "BOOM!"

As one of the Brickmuppet's Crack Team of Science Babes points out, "Boom!" does not do justice to what may be coming to the planet Mars.



"2x1010 Megatons is hard to visualize so think of it as being about this much 'splody."

It seems that recently discovered fast parabolic comet C/2013 A3 is going to pass pretty close to Mars. Exceedingly close. Best guess now has it passing within 63,000 miles of Mars. However the margin of error in plotting its course due to uncertainties about it's mass, its extreme speed and the limited time this object has been observed mean that the cone pf probability extends from 74,000 miles out from Mars to 0.000 miles.  This is much closer to Mars than the moon is to Earth.

The comet is moving exceedingly fast and is a retrograde orbit to boot so its relative velocity is around 35 miles per second, or 5 TIMES Earth escape velocity!

Since C/2013 A1 is a hyperbolic comet and moves in a retrograde orbit, its velocity with respect to the planet will be very high, approximately 56 km/s. With the current estimate of the absolute magnitude of the nucleus M2 = 10.3, which might indicate the diameter up to 50 km, the energy of impact might reach the equivalent of staggering 2×10¹º megatonnes! This kind of event can leave a crater 500 km across and 2 km deep. Such an event would overshadow even the famous bombardment of Jupiter by the disintegrated comet Shoemaker–Levy 9 in July 1994, which by some estimates was originally 15 km in diameter. - See more at: http://spaceobs.org/en/2013/02/25/comet-c2013-a1-siding-spring-a-possible-collision-with-mars/#sthash.SS7W2n7v.dpuf
The comet is 50 clicks across (by comparison the "Dinosaur Killer" was only 10 clicks in diameter). This would be a planet changing event.

Scott Lowther has thoughts on what the (admittedly unlikely) impact might mean for ambient Martian atmospheric pressure. Assuming it didn't blow the atmosphere clean off, it could be interesting indeed.

In any event, with a magnitude of 8.0 as seen from Earth, the comet should be visible with the naked eye in rural areas, which means we get a neat show regardless of whether it hits.

"Science Babe" is Shizune Hachimaki, from Katawa Shoujo.
Since C/2013 A1 is a hyperbolic comet and moves in a retrograde orbit, its velocity with respect to the planet will be very high, approximately 56 km/s. With the current estimate of the absolute magnitude of the nucleus M2 = 10.3, which might indicate the diameter up to 50 km, the energy of impact might reach the equivalent of staggering 2×10¹º megatonnes! This kind of event can leave a crater 500 km across and 2 km deep. Such an event would overshadow even the famous bombardment of Jupiter by the disintegrated comet Shoemaker–Levy 9 in July 1994, which by some estimates was originally 15 km in diameter. - See more at: http://spaceobs.org/en/2013/02/25/comet-c2013-a1-siding-spring-a-possible-collision-with-mars/#sthash.SS7W2n7v.dpu

Posted by: The Brickmuppet at 10:21 PM | Comments (2) | Add Comment
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1 Heh heh - it's about time that Martian character from Looney Tunes gets a taste of his own medicine.  Cue the "Mars-shattering Ka-Boom!"

Posted by: Siergen at Wed Feb 27 15:49:42 2013 (Ao4Kw)

2 Too bad I've already used the Ivonova quote.

Posted by: Mauser at Thu Feb 28 05:21:47 2013 (cZPoz)

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