Life on another Planet? Gliese 581d

[Kal'thzar]

So it appears we have a good candidate for life on another planet!

A red dwarf star 20 light-years away is again providing hints that it hosts the first definitively habitable planet outside our Solar System.

The planet Gliese 581d is at the colder outer edge of the "Goldilocks zone" in which liquid water can be sustained.

Now a study in Astrophysical Journal Letters suggests its atmosphere may keep things warm enough for water.

Source: http://www.bbc.co.uk/news/science-environment-13423085

Excited? Worried? Mild interest?

I'm simply fascinated by this, part of what got me into Physics (True, I'm going in a completely different direction...).

 

[Ajidica]

Time to see NASA/ESA/whatever the Russian Space Agency is called start collaborating and build some telescopes or drive systems to get a probe out past Voyager.

 

[Wolfbeckett]

Interested but just because the planet is potentially habitable doesn't mean there's more than a remote possibility of life. We still don't know if life on this planet is a total fluke or if there's a strong chance it will develop given similar conditions. Good chance to add to our knowledge though, I'd like to hear about whatever they find out .

 

[Ajidica]

Interested but just because the planet is potentially habitable doesn't mean there's more than a remote possibility of life. We still don't know if life on this planet is a total fluke or if there's a strong chance it will develop given similar conditions. Good chance to add to our knowledge though, I'd like to hear about whatever they find out .

It isn't unreasonable to expect to find bacteria on other planets. Bacteria have been found in South African mines surviving off of (if I recall correctly) nuclear decay. Tests have also been conducted on other types of bacteria by putting them on the outside of the space shuttle during a mission. The bacteria came back alive. If a bacteria can survive that, it stands to reason that bacteria can survive in many other places.

 

[kristopherb]

So it appears we have a good candidate for life on another planet!


Source: http://www.bbc.co.uk/news/science-environment-13423085

Excited? Worried? Mild interest?

I'm simply fascinated by this, part of what got me into Physics (True, I'm going in a completely different direction...).

Extremely interesting, its nice to know that planets like ours exist but we still need the technology to get there.

 

[Wolfbeckett]

It isn't unreasonable to expect to find bacteria on other planets. Bacteria have been found in South African mines surviving off of (if I recall correctly) nuclear decay. Tests have also been conducted on other types of bacteria by putting them on the outside of the space shuttle during a mission. The bacteria came back alive. If a bacteria can survive that, it stands to reason that bacteria can survive in many other places.

Yes life is remarkably tenacious once it develops, but that's not what I was saying. What I am saying is that we don't know how common it is for it to develop in the first place. Bacteria on this planet are able to survive well because they have a big advantage: They already exist. Whatever processes turned chemical soup -> life already happened for them, and now their survival is determined by the ol' survival of the fittest meme, which is indeed quite good at keeping things running. But we don't know how common that initial start is, and until we have some idea, getting our hopes up too high is probably just setting ourselves up for disappointment.

 

[bestrfcplayer]

Well, at least it's not a hoax.

 

[Kal'thzar]

Yes life is remarkably tenacious once it develops, but that's not what I was saying. What I am saying is that we don't know how common it is for it to develop in the first place. Bacteria on this planet are able to survive well because they have a big advantage: They already exist. Whatever processes turned chemical soup -> life already happened for them, and now their survival is determined by the ol' survival of the fittest meme, which is indeed quite good at keeping things running. But we don't know how common that initial start is, and until we have some idea, getting our hopes up too high is probably just setting ourselves up for disappointment.

Ahh buts that is precisely what is so exciting about finding a potential habitable planet. Its the first step in attempting to prove life exists outside of Earth (that is, step 1: Find suitable planets, Step 2: Do everything possible to check for life as we know it).

 

[Leoreth]

Exactly. The interesting thing isn't that there's a planet that probably has life.

It's interesting because for the first time we can gather some clues whether life is likely to evolve once the conditions for survival are met.

 

[Bill3000]

Reading the paper, it's saying that if the planet has an atmosphere of at least 10 bar CO2 (+ background gases) then it would have a global mean temperature above 0 C. This would be an equivalent to a partial pressure of 4-6 bar on Earth. For reference, the Earth's total atmosphere is ~1 bar, and CO2 composes 0.039% of that. Venus has an atmosphere of 93 bar, ~90 bar due to CO2. Naturally, this atmosphere would be inhospitable for humans due to the high pressure, although that certainly wouldn't be a problem for bacteria.

It's a plausible scenario for a planet of this type to have an atmosphere in this range. However, it doesn't talk about observational data showing this, but does offer observational tests to distinguish this scenario over others.

 

[choxorn]

However, Gliese 581d's denser air and dim red light from its host star would make for a murky environment that would be toxic to humans

That's another few minus points to being habitable to humans, but that doesn't make it uninhabitable to bacteria.

 

[PeteAtoms]

Yup. And the early Earth as it was a few billion years ago wouldn't have been very good for human life either IIRC.

 

[emzie]

Ahh buts that is precisely what is so exciting about finding a potential habitable planet. Its the first step in attempting to prove life exists outside of Earth (that is, step 1: Find suitable planets, Step 2: Do everything possible to check for life as we know it).

Step one is to check Mars, Europa and other moons of Jupiter / Saturn.

Exactly. The interesting thing isn't that there's a planet that probably has life.

It's interesting because for the first time we can gather some clues whether life is likely to evolve once the conditions for survival are met.

Probably?

 

[Bill3000]

It's not "probably", it's a "plausible scenario" - we do not yet have any experimental data showing that this kind of atmosphere actually exists on the planet.

 

[Skwink]

IDK, but we should probably nuke it. Just in case.

 

[Leonel]

I'm very interested! Maybe there might be a civilization there we could beam messages to if it indeed is capable of supporting life as we know it.

 

[Gustave5436]

It would take a probe like 300 years to get there (and even that's unlikely, due to international treaties forbidding nuclear powered spaceships), so for the time being it doesn't matter. Mars and ice moons like Europa are interesting, though

 

[Communisto]

(and even that's unlikely, due to international treaties forbidding nuclear powered spaceships),

Really? What a bummer

 

[Terxpahseyton]

Why are there treaties forbidding nuclear powered spaceships? Was someone afraid someone could launch a ship designed to launch nuclear attacks on earth?

 

[Ajidica]

Why are there treaties forbidding nuclear powered spaceships? Was someone afraid someone could launch a ship designed to launch nuclear attacks on earth?

It was probably the issue of our still signifigant rocket failure rate combined with the fact there was nuclear fuel on these rockets.