Thermal Effects from Comet 2013 A1 (Siding Spring) on Mars’ Upper Atmosphere

American Astronomical Society ^ | Oct 2013 | Morrison, Sarah J. ; Yelle, R

[Yosemitest]

American Astronomical Society, DPS meeting #45, #313.18
Published in Oct 2013

The Comet 2013A1 (Siding Spring) will pass within 123,000 km of Mars on October 19, 2014 at a relative velocity of 56 km/s.
The comet coma will impinge directly on the Martian upper atmosphere, causing significant perturbations.
We examine the thermal effects of the encounter with a first principle model of the upper atmosphere (100-200 km) that solves for the time-dependent thermal structure.
The thermal model includes solar EUV heating, radiative cooling, thermal conduction, and heating due to the impact of H2O molecules from the coma.
Assuming a H2O production rate of 10^28 molecules/s, the thermal pulse due to comet passage lasts approximately 5 hours and deposits on the order of 10^13 Joules in the Martian upper atmosphere.
The peak energy deposition is at an altitude of 140 km for a H2O-CO2 collisional cross section of 1E-16 cm2.
Altitudes above 140 km experience temperature increases that exceed 10 K over timescales of several hours with altitudes above 160 km having the greatest temperature increases of 25 K.
Thermospheric temperatures return halfway to their initial values roughly 8 hours after the comet encounter with thermal effects due to the comet becoming negligible 54 hours post-encounter.

[Yosemitest]

Okay, let's analyze this for a few moments.
The size of Comet 2013 A1 (Siding Spring) was estimated by Dr. Tony Phillips of NASA Science News

"The nucleus of the comet is probably 1 to 3 km in diameter, and it is coming in fast, around 56 km/s (125,000 mph)."

Don Yeomans of NASA's Near-Earth Object Program at JPL estimates

"It if does hit Mars, it would deliver as much energy as 35 million megatons of TNT."

But Leonid Elenin of SpaceObs.org stated the size of 2013 A1

" With the current estimate of the absolute magnitude of the nucleus M2 = 10.3, which might indicate the diameter from 10 to 50 km, the energy of impact might reach the equivalent of staggering 2×10¹º megatonnes! "

That's compared to Comet Ison's first estimates, very similar.
But yet the government couldn't tell us about Ison's data, and kept most of the data they did release on a 2 day delay?
And they can tell all of this when Comet Siding Spring is 548,226,055 km (or less now) from Earth?


Some say

"Interestingly, the closest approach has tightened a bit to 68,000 miles."

Dr. Tony Phillips stated

"ven a near miss is a potentially big event. The latest orbit solutions put the comet somewhere within 300,000 km of the red planet at closest approach. That means Mars could find itself inside the comet's gassy, dusty atmosphere or "coma." Visually, the comet would reach 0th magnitude, that is, a few times brighter than a 1st magnitude star, as seen from the Red Planet."

Now, my question is:

WHY CAN THEY TELL THIS ABOUT COMET SIDING SPRING AT THAT GREAT DISTANCE,
YET COULDN'T TELL THE SAME DATA ABOUT COMET ISON WHEN IT WAS MUCH, MUCH CLOSER TO US?

I THINK SOMEONE IS LYING TO US, OR NOT TELLING US THE WHOLE TRUTH !

[Yosemitest]

Ping, from Astronomy expert: Meteor likely in Upstate New York, but was it caused by Comet ISON?.
You might be interested in this data.

[Errant]

You might be interested in this data.

Very much so. Thanks!

[PapaBear3625]

the thermal pulse due to comet passage lasts approximately 5 hours and deposits on the order of 10^13 Joules in the Martian upper atmosphere.

Expressed that way, it seems like a lot of heat energy. Keep in mind, though, that a joule is a watt-second, so a kilowatt hour is 1000 * 3600 = 3.6 * 10^6 joules. So that energy release is about what you would get if 370,000 people ran their 1500 watt hair dryers for the 5 hour duration.

Effect on the surface temperature of Mars? Too small to measure.

[Yosemitest]

Obviously not,
or they wouldn't have run a model on it, and they wouldn't send more satellites to observe it,
so IT IS OF CONCERN TO NASA.


ScienceCasts: Collision Course? A Comet Heads for Mars ( 5:08 )

[cripplecreek]

Kinda like the fact that yearly meteor showers on earth don’t cook us.

[Errant]

Current projections have the closest encounter with Mars at 80,000 miles. That's darn close, but might put too far away for even the coma to envelope Mars.

http://en.wikipedia.org/wiki/C/2013_A1

What came to my attention was a strange correlation with the red horse prophecy in Revelation 6:3-4:

3 And when he had opened the second seal [second comet], I heard the second beast say, Come and see.

4 And there went out another horse that was red [Mars is Red] : and power was given to him that sat thereon to take peace from the earth, and that they should kill one another: and there was given unto him a great sword [I imagine the tail of the comet from earth will appear as a giant sword projecting from Mars at its closest approach].

While I think the prophecy is more likely a warning that Iran will acquire nuclear weapons, it's some pretty odd coincidences that might be viewed by some as second layer that relates to "signs in the heavens" of events forthcoming.

Also, I haven't checked a corrected Hebrew calendar, but the closest approach takes place at or very near the Feast of Trumpets.

[winoneforthegipper]

hmmm something is strange about this data....lol

[Talisker]

WHY CAN THEY TELL THIS ABOUT COMET SIDING SPRING AT THAT GREAT DISTANCE, YET COULDN'T TELL THE SAME DATA ABOUT COMET ISON WHEN IT WAS MUCH, MUCH CLOSER TO US?

I THINK SOMEONE IS LYING TO US, OR NOT TELLING US THE WHOLE TRUTH !

Shush, there there, nothing is going on. You just had a bad dream. Look over there, some shiny things. What's on TV? Isn't NASA wonderful? Just ask them, they have white lab coats, you can trust them. Don't worry your head with all of those big words and complicated diagrams, how boring. Don't you want to be popular? Isn't it fun when stars twinkle? Aren't they pretty? Do you know how to find the Big Dipper? There now, don't you feel better? Sleep... sleep... sleep...

[machogirl]

hmmm , Sheila Jackson Lee might want to be pinged on Mars weather. lol

[Graewoulf]

Great graphics! Thanks!

[PapaBear3625]

The video is about the effects of the comet nucleus (not just the tail) impacting Mars. Yes, a 3 km wide chunk of ice WILL have a significant energy release.

[Yosemitest]

Your sarcasm NAILS their attitude, alright !

[Errant]

Yeah, they're running an average for over a year. That's fine unless you want to account for other dynamics like CMEs from the sun, differences in solar wind pressure and etc. NASA is probably up on that but doubt we'll see it... ;)

[Errant]

[machogirl]

lol, that’s what i’m talking about. if there is turbulence in the air, the flag may be disturbed.

[Errant]

LOL!