[infectoid]

Your tea leaves are sound.

I think this is why those of us interested in this are very much hanging out for results from our explorations of Mars. It's pretty much our only opportunity to see if life emerged twice in the same planetary system under similar conditions.

What are the chances?

On the positive side Mars had pretty much all the ingredients for life (chemically) and had a long enough period for at least something intersting to develop. On the negative side, the environment was still different to ours (gravity, climate, whether, etc).

We still aren't clear on what conditions need to met for like to get going. This is why both positive or negative results on Mars are exciting.

My favourite theory is that life actually takes ages to get started so much so that it started on Mars and finished on Earth (from Mars being impacted and debris making it to Earth). Kind of like a passing of the torch.

Mars: "Crap. I'm dying. Hey Earth, can you take this thing I've been working on?"

Earth: "Yep. No worries. I got this. Will try to send some back in a few billions years. Take care."

[opportune]

>It's pretty much our only opportunity to see if life emerged twice in the same planetary system under similar conditions.

Well there's also Titan, Enceladus, and Europa right? Titan is by far the most exotic but it could serve as an example of what happens when life evolves under a radically different environment. It has some complex organic molecules there and a very interesting/varied geology and topology. Enceladus and Europa could exhibit very similar conditions to those of the deep sea on Earth as well, which could very well be where life originated. Also at one point even Earth could have became a "snowball" planet and still able to sustain life: https://en.wikipedia.org/wiki/Snowball_Earth

[aiyodev]

Unfortunately, we cannot be certain life on other planets in our solar system did not originate on our own. It has been determined that meteor that killed the dinosaurs possibly seeded planets and mas far out as Saturn with microbes.

[codesushi42]

>It's pretty much our only opportunity to see if life emerged twice in the same planetary system under similar conditions.

You mean carbon based life. Methane based life may be a possibility, and you wouldn't have found it on Mars. You might find it on Titan.

[dredmorbius]

Methane is an organic (carbon-chain) molecule: CH4.

Titan would have a low-temperature carbon-based chemistry, but it would remain carbon-based if focused on methane.

Alternative hypothetical biochemistries usually focus on silicon.

[onlyrealcuzzo]

Wasn't Venus at one time more Earth like than Mars? Why is Mars the only chance?

[satyenr]

Because Venus’ atmosphere is full of Sulphuric Acid and various greenhouse gases which wouldn’t allow life as we know it to exist.