A collision between Mars and Jupiter

[Marcus MacGregor]

Hello,

A few years back I had the idea that the topography of Mars could have been largely created by a close encounter with Jupiter. I posted it on several forums and got some great responses. (And some angry trolls, but hey it is the internet so what can you do)

The introduction video to this idea is here:

http://youtu.be/mGOsw8CLxmE

This is a flyby that tears out the Hellas basin. I found that a great many people thought that it went by the Roche limit. I'd just like to point out ahead of time that Mars has a fairly high density so the Roche limit does not come into play.

I made a video showing the location of some things around Jupiter because of this common confusion.

http://youtu.be/PJumdRcZcUA

I just made a video showing what I consider to be the most easily grasped evidence of this:

http://youtu.be/zHGX_ZQwGdA

I have a video planned for the trajectory of the event. I found that many people are convinced that falling into Jupiter or being flung out of the solar system are the only options. I found many planetary scientists I contacted recommended the L4 or L5 lagrangian point as the start of the trajectory. I have decided to adopt this rather than my initial idea of a highly elliptical Mars triggered by a orbital resonance. L4 would accelerate while L5 would decelerate leading to the correct Hamiltonian.

I also have a video planned for the timing of the event. One commenter noted that we would of totally noticed this happening. I guess he was thinking that it was breaking news. We have been watching Mars for quite some time and although it saddens me that I have to make it explicit- This event occurred before the invention of astronomy.

So I'm posting on this forum to see if there is other flaws of this idea that I have not addressed. I want to run it by as many people as possible before I start the laborious task of submission to journals.

So, if you think you have a debunking concept or just a facet of the idea that needs more depth please tell me. It may be something I have worked out already but have not mentioned, but hopefully it might be something that I have missed. I have had this idea for awhile so it appears obvious to me, I understand if it does not appear so to you; I'd like to know why you have a dubious perspective.

If you don't accept the idea but don't have a reason why, perhaps you can share it with someone who can come up with a reason.

If you like the idea and have a piece of supporting evidence I have not mentioned, that would be great too.

If you simply like the idea, I always appreciate a like, share or nice comment. The internet can be a very negative place.

Thank you.

[Rakaydos]

Arnt the l4 and L5 points stable? (that is, falling out of the point changes your orbital velocity such they you fall back into it) How do you get a jupiter flyby from the stable lagrange points?

[Sirrobert]

Intriguing idea. But what could possible cause a single flyby, followed by a stable orbit?

[Rakaydos]

Particularly if you need to match the inclination of the hellas bason on mars's rotation, with the inclined trajectory mars would be launched into by passing "under" jupiter as your videos show. How does mars get back to the ecliptic afterward? (or if the flyby wasnt very inclined, how did the helas basin get so far south?)

[Scotius]

Such event would leave plenty of evidence - perturbed orbits of dozens of asteroids, short-cycle comets and Jovian moons. Even after millions of years astronomers would know that "something" happened out there.

[Kryten]

Have you tried any actual simulations of this scenario?

[kahlzun]

My main issue with this is Occam's razor. This potentially explains one slightly anomalous feature, while raising dozens of additional problems which would need answering.

Essentially, Mars's composition (iron-rich rocky planet, limited water) indicates it was most likely formed within the 'inner' solar system (planets out by Jupiter tend to be either icy moons or gas giants).

Mars is far, far larger than any of the moons currently orbiting the gas giants (50% bigger than Ganymede), and it only has a tenuous atmosphere. Mars has a higher density (3.93 g/cm3) than the large moons such as Ganymede (1.94 g/cm3) or Titan (1.88 g/cm3)

There are no object approaching Mars's size past Mars orbit, save the gas giants.

Are you suggesting Mars was formed as a standalone planet out there? Why didn't it get a hydrogen atmosphere?

Are you suggesting Mars was once a moon of one of the other planets? Why is it so much bigger than the other moons?

Are you suggesting Mars was formed at the L4/L5 point for Jupiter? What caused that much mass to coalesce there? Why does it have the hallmarks of being 'formed' in the inner solar system? How did it get out of the lagrange point? It takes billions of years for a planet to form and cool enough to have surface features that are not plastic, what caused the jump from the previously stable position.

As your posit replaces one simple question with multiple, much harder questions, Occams razor states its probably not the case.

Edited January 28, 2015 by kahlzun

[brdavis]

Or at a deeper level… why bother? What questions or problems does this address that don't already have more viable, better tested explanations? In particular, I find the idea of a close encounter between two planetary-scale objects creating Hellas to be… well, completely contrary to what would be expected?

And the Roche limit certainly applies… you just have to account for the densities of the two objects.

[Whirligig Girl]

Probably not. An interesting idea, but just remember that you set out to find out a thing based on what might be, not to prove what you think it is. You test a hypothesis, not constantly try to prove it. You may know this, this is just a reminder to keep an open mind to criticism.

Mars' density is around the same as Earth's density. It's not abnormal in density. If it passed within the Jovian Roche limit, it would definitely become a ring system. Mountains do form in craters. It's an interesting way that shockwaves shape high impact craters. There was a pretty decent one near the Apollo 11 landing site. Mars' different hemispheres being so different can much more easily be explained by an impact from a protoplanet (about the same size, in scale, as Ike to Duna) that hit Mars and flattened out one side.

Really the biggest problem is explaining how Mars got from a Jovian flyby to a normal circular-ish orbit around the sun. And how it isn't made of the same stuff as objects that formed out there (like the Jovian moons), but is much more like the other terrestrial planets.

- - - Updated - - -

Or at a deeper level… why bother? What questions or problems does this address that don't already have more viable, better tested explanations? In particular, I find the idea of a close encounter between two planetary-scale objects creating Hellas to be… well, completely contrary to what would be expected?

And the Roche limit certainly applies… you just have to account for the densities of the two objects.

ANY body held together by gravity is affected by the Roche limit. Planets are only very very slightly held together like rocks are, by molecular forces. It's insanely negligible compared to the gravitation holding the planet together. Not to mention that Mars has a normal Earth and Venus like density. Mercury, on the other hand, is remarkable dense. Smaller than two of the Jovian moons, its surface gravity is comparable to Mars.

[Bill Phil]

Mars' density has little to do with the Roche limit. It's the strength of gravity on all the mass of Mars. When Mars' gravity is beaten by another body at the surface, that's when the Roche limit is hit.

Chances are Mars' topography is caused by its atmosphere and it's low gravity, being similar to Earth a long time ago, but with lower gravity and this larger features.

Perhaps Mars was destined to have more mass than it does now, maybe about 10* it's current mass, but then Jupiter came into the outskirts of the inner solar system robbing Mars, before Saturn's gravity could pull Jupiter back out.

[Sirrobert]

Wasn't our Moon formed by a collison between earth and another planet? So collisions are not unheard of, while a planet taking a 1 orbit trip out ot Jupiter to get ripped up, and than back to a regular orbt is

[Bill Phil]

Mars is only a little more than 1.5 AU from the sun at most, compared to Jupiter's 5 AU. Very unlikely simply based on the distances involved.

[78stonewobble]

Still, the idea of an object "grazing" the roche limit... is rather interesting

[KerikBalm]

The scenario described in that video is completely impossible and absurd.

A planet cannot "collide" with a lagrangian point between it and another planet.

Much like the barycenter moves if you move one object closer or farther from the other object, so do the lagrangian points.

There would be no "zero gravity" point, and it would be pretty absurd for such to exist, and then fall towards jupiter to from the hellas basin, while other stuff remains gravitationally bound and craters the rest of the surface...

Nor would such post "interaction" cratering describe the dichotomy of the martian surface.

Its a big impact basin, and gravitational interactions would never make something like that.

It never came close to approaching the roche limit with jupiter. If there was a "close shave" within the roche limit, the planet would basically start to break apart, and then the rubble pile would accrete again.