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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

New Theory: Catastrophe Created Mars' Moons

By Leonard David Senior Space Writer

posted: 07:00 am ET 29 July 2003

PASADENA, California – The two moons of Mars – Phobos and Deimos – could be the byproducts of a breakup of a huge moon that once circled the red planet, according to a new theory. The capture of a large Martian satellite may have taken place during or shortly after the formation of the planet, with Phobos and Deimos now the surviving remnants.

Origin of the two moons presents a longstanding puzzle to which one researcher proposed the new solution at the 6th International Conference on Mars, held here last week. "Nobody has been able to explain the origin of Phobos and Deimos," said S. Fred Singer of the University of Virginia’s Science & Environmental Policy Project in Arlington, Virginia.

Violating laws

Based on research performed as a visiting scientist at the Lunar & Planetary Institute in Houston in October 2002, Singer said that conventional hypotheses about the moons either violate physical laws or have difficulty accounting for their observed orbits

Singer reported at the meeting that "there are no ready alternatives to explain the origin of the Martian moons."

At present, both satellites have near-circular and near-equatorial orbits. Phobos’ orbit, however, has been observed to shrink since its discovery in 1877. The present track of Deimos -- just beyond the synchronous limit where it nearly matches the spin rate of Mars – is an important data point, Singer said. "Is that by accident? I don’t think so…it gives you a clue about its origin," he told SPACE.com.

Through a complex set of orbital calculations involving Mars, the large hypothetical Mars moon itself, and tracing back in time the past and present whereabouts of Phobos and Deimos, Singer believes he has a case. In the Singer scenario, the close proximity of a large original moon to the red planet – captured in Mars synchronous orbit -- would have eventually fractured the object. Gravitational pushes and tugs would have turned it into a rubble pile that would still cling together gravitationally. "Forces would soon drive the largest pieces into Mars, with the smallest pieces remaining as Phobos and Deimos," Singer said. In the breakup process, the most massive pieces would spiral in far more rapidly, crashing into the planet. "We need to look for some sign that these existed."

Phobos: going, going, gone

A fundamental prediction by Singer is that the moons are similar in composition and petrology. However, Phobos and Deimos do not appear to be comparable. That distinction is obvious in looking at the differences in their regoliths – each moon’s topside covering. "We need both surface and deep samples to decide this issue, and to investigate whether Phobos and Deimos once formed as parts of a larger body, most of which has now disappeared, perhaps by impacting on Mars," Singer said.

Singer said Phobos will die in a few million years. "We’re lucky in the sense that we’re seeing Phobos while it’s still around," he said.

Destination Deimos

Singer has plans for Deimos. The scientist believes the moon would serve as a natural space station for future human explorers.

"First of all, humans on the surface of Mars cannot really do the exploration directly. They have to use rovers to get around. To go from the equator to a pole on Mars just takes too long. It’s a big, dangerous journey," Singer said. What Singer envisions is a Deimos gateway to extensive Mars exploration. An encampment of astronauts would reside on the Martian moon. From there, dozens of rovers could be autopiloted, in real-time.

"There would be no time delay, or so short that it’s within the human reaction time," Singer said. From Deimos, quick, down-to-the-surface sorties could be undertaken by humans to select areas, he added.

"This would be a 15-year project, as I look at it. It would cost roughly $30 billion, funded at some $2 billion a year average. That’s well within the existing NASA budget," Singer said. On the political side, Congress is not likely to fund a long series of robotic roving probes to Mars that extends over decades. "That would not be a very efficient way of studying Mars. If you want to solve the really big problems of Mars, like origin of life, you need to do this in one fell swoop," Singer concluded.


TOPICS: Culture/Society; Extended News; Foreign Affairs
KEYWORDS: asteroid; asteroids; bodeslaw; catastrophe; catastrophism; deimos; doom; fear; grooves; hemisphereofcraters; impact; impacts; mars; martiandesert; martianequator; martianimpact; moon; moons; oppositehemisphere; origins; pascalrosenblatt; patten; phobos; rochelimit; rocheradius; sfredsinger; stickneycrater; striations; terror; titiusbode; titiusbodeslaw; tvf; vanflandern; xplanets
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To: Genesis defender
Tell them to behave, or we'll bring Hillary back! :p
21 posted on 07/29/2003 10:16:30 AM PDT by Constantine XIII
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To: RightWhale

Heres why I want to go.

22 posted on 07/29/2003 10:16:59 AM PDT by corkoman (did someone say cheese?)
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To: corkoman
whoa - bigger than expected
23 posted on 07/29/2003 10:18:06 AM PDT by corkoman (did someone say cheese?)
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To: #3Fan
it is plastered on one side

Look again. One side is blasted off. Just like earth. Where is the missing crust?

24 posted on 07/29/2003 10:23:00 AM PDT by RightWhale (Destroy the dark; restore the light)
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To: D Rider
hey have likewise discovered two lesser stars, or satellites, which resolve around Mars, whereof the innermost is distant from the center of the primary planet exactly three of his diameters, and the outtermost five; the former revolves in the space of ten hours, and the latter in twenty-one and a half; so that the squares of their periodical times are very near in the same proportion with the cubes of their distance from the center of Mars, which evidently shows they to be goverened by the same law of gravitation that influence other heavenly bodies.

This discription is within 20% accurate

It's not within 20% accurate. The orbital radii of the moons are at 9378 km and 23459, or about 1.4 and 3.5 diameters.

Still, it is remarkable.

25 posted on 07/29/2003 10:23:28 AM PDT by Right Wing Professor
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To: corkoman
Do you experience HTML accidents often? If so, you might want to reconsider the career of Mars astronaut. Mars will not tolerate HTML formatting errors.
26 posted on 07/29/2003 10:26:00 AM PDT by RightWhale (Destroy the dark; restore the light)
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To: Right Wing Professor
I was partial to the double-barrel shotgun for most occasions and the chainsaw for close quarters. But nothing beat letting loose with the BFG and watching 12-15 demonspawn explode and splatter. Ahh, those were the days....
27 posted on 07/29/2003 10:44:19 AM PDT by Genesis defender (Jesus still loves you.)
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To: Genesis defender
But what do you do when the Space Marines discover a demon-infested gateway to Hell?

LOL! Good one!

28 posted on 07/29/2003 11:04:27 AM PDT by FierceDraka ("I am not a number - I am a FREE MAN!")
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To: Genesis defender; FierceDraka; Right Wing Professor
A trip back down "memory lane" for y'all...

You're a marine, one of Earth's toughest, hardened in combat and trained for action. Three years ago you assaulted a superior officer for ordering his soldiers to fire upon civilians. He and his body cast were shipped to Pearl Harbor, while you were transferred to Mars, home of the Union Aerospace Corporation. The UAC is a multi-planetary conglomerate with radioactive waste facilities on Mars and its two moons, Phobos and Deimos. With no action for fifty million miles, your day consisted of suckin' dust and watchin' restricted flicks in the rec room.

For the last four years the military, UAC's biggest supplier, has used the remote facilities on Phobos and Deimos to conduct various secret projects, including research on inter-dimensional space travel. So far they have been able to open gateways between Phobos and Deimos, throwing a few gadgets into one and watching them come out the other. Recently however, the Gateways have grown dangerously unstable. Military "volunteers" entering them have either disappeared or been stricken with a strange form of insanity-babbling vulgarities, bludgeoning anything that breathes, and finally suffering and untimely death of full body explosion. Matching heads with torsos to send home to the folks became a full-time job. Latest military reports state that the research is suffering a small set-back, but everything is under control.

A few hours ago, Mars received a garbled message from Phobos. "We require immediate military support. Something fraggin' evil is coming out of the Gateways! Computer systems have gone berserk!" The rest was incoherent. Soon Afterwards, Deimos simply vanished from the sky. Since then, attempts to establish contact with either moon have been unsuccessful. You and your buddies, the only combat troop for fifty million miles were sent up pronto to Phobos. You were ordered to secure the perimeter of the base while the rest of the team went inside. For several hours, your radio picked up the sounds of combat: guns firing, men yelling orders, screams, bones cracking, then finally, silence. Seems your buddies are dead. It's Up To You Things aren't looking too good.

You'll never navigate off the planet on your own. Plus, all the heavy weapons have been taken by the assault team leaving you with only a pistol. If only you could get your hands around a plasma rifle or even a shotgun you could take a few down on your way out. Whatever killed your buddies deserves a couple of pellets in the forehead. Securing your helmet, you exit the landing pod. Hopefully you can find more substantial fire power somewhere within the station. As you walk through the main entrance of the base, you hear animal like growls echoing throughout the distant corridors. They know your here. There's no turning back now.


29 posted on 07/29/2003 11:31:57 AM PDT by Pyro7480 (+ Vive Jesus! (Live Jesus!) +)
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To: Pyro7480
Hard to tell which wasted more of my time: that game , or FR. FR was probably more educational, but nothing here matches the sensation of a chainsaw going into a Cacodemon's eye-scoket.
30 posted on 07/29/2003 11:54:06 AM PDT by Right Wing Professor
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To: Right Wing Professor
Tell me about it. I can definitely relate to that. Doom "wasted" a good part of my time in high school, and FR in college and now. ;-)
31 posted on 07/29/2003 11:57:16 AM PDT by Pyro7480 (+ Vive Jesus! (Live Jesus!) +)
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To: Quatermass
The most probable theory advanced so far is that Phobos & Deimos are the residual of a catestrophic impact of an asteroid into a pre-existing larger moon.
32 posted on 07/29/2003 12:02:57 PM PDT by Natural Law
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To: RightWhale
Look again. One side is blasted off. Just like earth. Where is the missing crust?

This picture seems to show plastering though: Plus topographical studies show that the plastered side is sitting on top of the exposed unplastered side.

33 posted on 07/29/2003 2:23:00 PM PDT by #3Fan
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To: #3Fan
Plus topographical studies show that the plastered side is sitting on top of the exposed unplastered side.

Let me rephrase that. Topographical studies (or studies of the crust) show that the loose pastered debris is sitting on top of a former surface that is visible on the unplastered side.

34 posted on 07/29/2003 2:28:22 PM PDT by #3Fan
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To: #3Fan
It could be that. There is the lower side that is relatively uncratered and the high side that is extensively cratered. Whether the low side is what was left after removal of material, or the high side is material that was added is a question that might be resolved by extensive geological digging. It seems that each successful probe to Mars raises questions but answers little.

When they taught in the 50s the story of where the moon came from, they had diagrams showing the moon material being ripped from one side of the earth's crust presumably where the Pacific Basin is today. Something similar could have happened to Mars, but there is of course nothing left of this material except the two small pieces Phobos and Deimos, if they came from that event and aren't just some kind of captured asteroids. There is no reason to expect that a captured asteroid would settle into a circular orbit except that is what happens apparently around Jupiter and Saturn. What could circularize such orbits when there are only a couple of small moons?

35 posted on 07/29/2003 2:59:23 PM PDT by RightWhale (Destroy the dark; restore the light)
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To: RightWhale
When they taught in the 50s the story of where the moon came from, they had diagrams showing the moon material being ripped from one side of the earth's crust presumably where the Pacific Basin is today. Something similar could have happened to Mars, but there is of course nothing left of this material except the two small pieces Phobos and Deimos, if they came from that event and aren't just some kind of captured asteroids. There is no reason to expect that a captured asteroid would settle into a circular orbit except that is what happens apparently around Jupiter and Saturn. What could circularize such orbits when there are only a couple of small moons?

The faster something travels the more speed it loses when it collects space dust, meteors, etc., perhaps. If there was a giant disentegration of a large planet, then all the extra dust and debris in the inner solar system would serve as a drag on any object in an elliptical orbit because objects in an elliptical orbits would have portions of their orbits where they are going faster than the dust and objects their colliding with before gravitational attraction sped up the dust and debris right before impact. It would be more of a drag when the object is going fast and less of a drag or perhaps even a push when the object is going slow in it's various positions of it's elliptical orbit. Over time, that would circularize the orbit, I would think, especially on a relatively small planet like Mars, or on a small moon like Phobos. As the inner solar system has been cleaned up over time, this drag is less apparent now but it could've been a lot greater right after the event. Maybe Mars hasn't collected enough debris and dust to circularize it's orbit, I don't know. From what I understand Mars orbit isn't all that stable. It could mean it hasn't been where it's at for very long.

36 posted on 07/29/2003 4:17:50 PM PDT by #3Fan
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To: #3Fan
It seems that where there are several bodies, moons or planets with some mass and gravity in orbit around a primary, they tend to affect each other's orbits in such a way as to circularize all of them. It might be that one of them is left wildly elliptical and that one gathers up energy and gets flung completely out of the system or sent into the primary itself leaving the rest with quieter orbits. Just like people, older neighborhoods tend to be quieter.
37 posted on 07/29/2003 4:48:08 PM PDT by RightWhale (Destroy the dark; restore the light)
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To: Right Wing Professor
[B]ut nothing here matches the sensation of a chainsaw going into a Cacodemon's eyesocket.

Are you kidding me? You'd have to have 'nads to try a stunt like that. Those guys usually took a giant-size chunk outta my face before I could fire up the 'saw. I'd rather shove both barrels of my shotgun into its mouth and pull the trigger. Or whip out the plasma rifle and liquify its eyeball.

I've uttered more naughty words than I can count stalking those things late at night. Of course, nothing beat the feeling of hearing the blood-curdling roar of a Pinkie behind you, whipping around, then blowing him away.

38 posted on 07/29/2003 5:34:23 PM PDT by Genesis defender (GOD mode is for pansies.)
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To: Pyro7480
AHHH! Mancubus! I hated those guys. Thanks for the flashback, though.
39 posted on 07/29/2003 5:37:26 PM PDT by Genesis defender (GOD mode is for pansies.)
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To: RightWhale
There is one way to make a moon in a circular orbit that I have never seen mentioned in the astrophysics books. You could call it "Roche lifting". Whenever two massive bodies pass within the Roche limit (about 3 radii) of one another, the more massive one will tidally disrupt the less massive body.

The same effect that causes comets to break up as they pass Jupiter could lift the crust from a planet to form a moon, without a direct impact between the two bodies.

Of course, if the bodies pass too close, the less massive one becomes an asteroid belt.

40 posted on 07/29/2003 6:33:56 PM PDT by e_engineer
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