Mars and Earth Weren't Always Neighbors, Says New Study

Monday, 18 December 2017 - 11:06AM
Monday, 18 December 2017 - 11:06AM
Mars and Earth Weren't Always Neighbors, Says New Study
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While we may all like to think of Mars and Earth as being best friends forever, two planets side by side that share a lot of similarities, we might not be correct in assuming that Mars has always been in our neck of the woods.

According to a new study from researchers in the US, UK, and Japan, it's possible that Mars actually formed far away from Earth in the solar system's asteroid belt before moving in next door to our own planet.

While that's an exciting theory, it's also far from the most likely explanation for Mars' origin. The planet was probably always in its current spot, found snugly in between our world and the rocky barrier that divides the solar system's inner and outer planets.

That said, if Mars was always in its current position, then its mineral makeup doesn't make sense. The planet seems to share an awful lot in common with asteroid material, leading scientists to run a series of simulations to see if they could come up with a better reason for why Mars is in its current location.

Most simulations returned the same results, suggesting that Mars probably formed in the exact place that it can be found now, but a small fraction of the computer models instead provided evidence that Mars formed out of chunks of the asteroid belt, growing larger and attracting more mass, before eventually getting sucked into Jupiter's large gravity well and shifting to its current location.

This is a longshot, and is far from the most likely explanation for the Red Planet's unique makeup, but it's not entirely impossible.

According to Stephen Mojzsis of the University of Colorado, co-author on the paper that displayed these results, when dealing with the universe, just because something is unlikely, it doesn't mean that it's impossible:

Opening quote
"Low probability means one of two things: that we don't have a better physical mechanism to explain Mars' formation or in the enormous panoply of possibilities we ended up with one that is relatively rare..."Given enough time, we can expect these events. For example, you'll eventually get double sixes if you roll the dice enough times. The probability is 1/36 or roughly the same as we get for our simulations of Mars' formation."
Closing quote

Certainly, there is some evidence from other scientific studies to suggest that Mars might have traveled around a bit before settling down nearby Earth. If Mars began life further away from the Sun, it wouldn't have ever been as hot and humid as has always been assumed, which fits with a recent theory that suggests that we've all been overestimating just how warm and wet the planet was, even in its youth.

There's also something to be said for Jupiter shifting its gravitational strength over time, as a theory claims that the planet expanded from a relatively small, dense rock to its current large state as it pulled additional matter from the Sun over time.

This theory is unlikely, but with so many things that we don't understand about the universe, it's not impossible that Mars might be more of a wandering spirit than we'd previously believed.

Here's hoping that the Red Planet doesn't decide to wander off again; a lot of important space exploration missions are counting on Mars staying exactly where it is for the foreseeable future.