Posted on 03/15/2007 2:14:24 PM PDT by blam
Did a giant impact create the two faces of Mars?
16:29 15 March 2007
NewScientist.com news service
David Shiga, Houston
Mars's northern hemisphere is lower in elevation – by about 5 kilometres – than its southern hemisphere (see image below). This coloured topographical map shows low elevations in blue and high elevations in yellow and red. The map is centred on a latitude of 55° north (Illustration: Mike Caplinger/MSSS)
Mars's southern hemisphere is higher and more heavily cratered than the northern hemisphere, suggesting it is older terrain. The two low elevations (blue) in this map, which is centred on the southern mid-latitudes, are the impact basins Argyre and Hellas (Illustration: Mike Caplinger/MSSS) The impact of a giant asteroid could explain why Mars has two very different faces – but only if it struck the planet with a glancing blow, computer simulations suggest.
A longstanding puzzle about Mars is why its northern and southern hemispheres are so different. The northern hemisphere is much flatter and lies lower than the southern hemisphere, with a difference in elevation between the two of about 5 kilometres.
In the 1980s, scientists suggested a giant impact by an asteroid about 300 kilometres across in Mars's early history could have led to a permanent depression in the planet's northern hemisphere.
Now, two teams of scientists have created the first computer simulations testing whether such an impact could have produced the observed differences.
Shawn Hart of the University of California in Santa Cruz, US, led one of the simulation teams. His team found that such an impactor would produce huge amounts of lava – enough to cover the planet in an ocean of molten rock somewhere between 14 and 48 kilometres thick. That would have ended up erasing any record that an impact happened
(Excerpt) Read more at space.newscientist.com ...
Catastrophism Ping.
Several years ago Van Flandern and Hoagland put forth the hypothesis that Mars was hit by an exploding planet of which it was the secondary of the two-planet system. The asteroid belt is what remains of the larger body, and half of the crust of Mars including its atmosphere and most of its oceans were blown off in the explosion.
At a depth of 36 feet.
I know about the one "face," but I never heard about a second one.
I've seen the face on the left, but the one on the right I'm guessing is the second face. Quite scary, especially those letters tatooed on his arm.
I NEVER pass up an opportunity to post this pic. ;o)
Maybe a large asteroid that had the remarkable likeness of Kerry?
Ya can't fool me!
FMCDH(BITS)
You stumped me with the last acronym? Help!
NN, hope you don't mind me jumping in...
From
My
Cold
Dead
Hands
(Blood
In
The
Streets)
Thanks Z-man!
Red Planet's Ancient Equator Located
Scientific American (online) | April 20, 2005 | Sarah Graham
Posted on 04/24/2005 11:18:25 PM EDT by SunkenCiv
http://www.freerepublic.com/focus/f-chat/1390424/posts
Giant Impact Basins Trace the Ancient Equator of Mars
Jafar Arkani-Hamed
Earth and planetary sciences, McGill University
Montreal, Quebec, Canada
http://www.agu.org/pubs/pip/2004JE002343.pdf
New Theory: Catastrophe Created Mars' Moons
space.com | 29 Jul 03 | Leonard David
Posted on 07/29/2003 8:56:47 AM PDT by RightWhale
http://www.freerepublic.com/focus/news/954539/posts
similar, but extrasolar:
Spitzer Sees the Aftermath of a Planetary Collision
Universe Today | Jan. 10, 2005 | Dolores Beasley and Gay Yee Hill
Posted on 01/13/2005 8:50:18 PM PST by SunkenCiv
http://freerepublic.com/focus/f-chat/1320521/posts
Immense ice deposits found at south pole of Mars
Reuters via Yahoo! | 3-16-07 | Will Dunham
Posted on 03/15/2007 4:01:58 PM EDT by Pharmboy
http://www.freerepublic.com/focus/news/1801465/posts
Wait for the animation...
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