Space

8781 readers

101 users here now

Share & discuss informative content on: Astrophysics, Cosmology, Space Exploration, Planetary Science and Astrobiology.

Rules

Be respectful and inclusive.
No harassment, hate speech, or trolling.
Engage in constructive discussions.
Share relevant content.
Follow guidelines and moderators' instructions.
Use appropriate language and tone.
Report violations.
Foster a continuous learning environment.

Picture of the Day

The Busy Center of the Lagoon Nebula

Related Communities

🔭 Science

🚀 Engineering

🌌 Art and Photography

Other Cool Links

founded 1 year ago

MODERATORS

[email protected]

529

Comparison of a picture from Mars (left) to a picture from Earth (right) (lemmy.world)

submitted 2 months ago by [email protected] to c/[email protected]

65 comments fedilink hide all child comments

you are viewing a single comment's thread
view the rest of the comments

[–] Naz -3 points 2 months ago (1 children)

There's a non zero chance that Mars is a remnant of the planetary impact that occured to the Earth ~ 3.5 BYA. The issue is that's a really loose hypothesis, but the speculation is that Theia - which impacted Gaia (old Earth) was an ice planet / water world, which gave us most of our oceans.

Evidence of water evaporation on Mars therefore makes sense, as a catastrophic effect (such as planetary impact) would indeed cause the atmosphere to boil off, leaving behind these dry lakes and riverbeds.

I personally haven't spent enough time on Mars to make a substantial conclusion, there wasn't enough time to do any science between the sheer insanity of basic survival on a planet that seems uniquely designed to kill you and crush your spirit before doing so.

I totally approve of your analysis however, and it's proof why geologists deserve a seat on the interstellar jumpships :3

[–] anindefinitearticle 10 points 2 months ago (2 children)

No, Mars was not formed by the moom-forming impact event between Gaia and Theia. The moon is the remnant you're talking about, not Mars.

[–] [email protected] 5 points 2 months ago

Also, a recent paper shed some doubt on the impact theory (apparently Earth and Moon isotopes are too similar), so the impact might not have happened or it might have been different than previously thought (glancing and causing the proto-Earth to spin itself apart, or strong enough to completely melt and mix both objects).

In any case, though, yeah, Mars has the wrong composition, size, and orbit for it to have been involved in any impact with Earth. The mistake probably came from Theia often being described as ‘Mars sized’.

[–] [email protected] 3 points 2 months ago (1 children)

I think they mean Mars could be Theia.

[–] [email protected] 1 points 2 months ago (1 children)

I think the fact that it’s really far away, in a circular orbit, and doesn’t have a big chunk missing is still a good sign that mars isn’t theia

[–] [email protected] 1 points 2 months ago* (last edited 2 months ago)

Why would it have a chunk missing after all this time? If it did could we even tell? Whatever it was isn’t still in the area so being far away may not mean much. Circular orbit is probably biggest reason it’s likely not Mars, although it could have evened out relatively recently.

This simulation shows the Mars sized object merging with Earth so there goes that theory.