What if we found an earthlike planet with no life?

Originally posted by bigbert81
Well there are 3 things necessary for life:

1) Hydrogen - THE most abundant element in the universe

2) Carbon - Another VERY common element

3) LIQUID water - the tricky one

If you want life based on the same biochemistry as Earth's , than yes those would
be necessary, but they are from being universally required.

For instance, a Silicon based lifeform would'nt need water or carbon.

I do think though that to find life, our first search should be similar planets though.

Originally posted by Badge01
Alien bacteria, fungi, and other microorganisms are likely to be quite deadly to humans. It's unlikely that would could develop immunity to them.

A very good point, I actually never gave that to much thought until i read a SciFi novelette
about a planet with especially toxic life on it.

I think though that we may actually encounter some planets where there would be
a neutral effect, that is the two could exist side by side without killing each other and
some places where are own germs will be dominant and allow us to be immune,
though at the cost of eventually killing the natural ecosystem, if nothing was done.

In the end though I think that we'll more or less bioform ourselves and Terraform
and/or xeno-bioform the alien environment to be able to exist on alien worlds.

Who know, maybe Humanity will change with each new world discovered, so that
everyone could exist everywhere.

[edit on 8/18/2007 by iori_komei]

Originally posted by Badge01
Future astronauts may actually find that in order to 'move into' a new ecosystem it is necessary to sterilize it.

Alien bacteria, fungi, and other microorganisms are likely to be quite deadly to humans. It's unlikely that would could develop immunity to them.

Or, it might be a lot easier to just make a vaccine or whatever that would protect us from alien whatever. Or something like that, im not a doctor obviously.

I just dont think the sterilize the planet thing would work because of all the nooks and crannys.
Something will always survive somewhere.

The fact is we haven't found one yet. I could just say what if we found life on another planet like Earth...

Kind of strange if we're the only life in this universe... more like impossible..

I would reason that if the alien world developed life according to our understanding, roughly parallel to earths, that plants and animals would arise simultaneously in a symbiotic relationship. I also think we would be far more likely to find another world in its own "age of dinosaurs" complete with unbelievably strange creatures and more importantly, really nasty carnivores. Considering that here the dinosaurs ruled for millions of years and we had only been around for a couple hundred thousand.

Sign me up for the science ship mission.

What if the plants were really the intelligent beings? Time is relative, maybe a planet with a long day cycle(100 earth years), or two suns . Slow movement, make their own sustainable power.

Come to think of it they may be the only intelligent life on this planet.

Lets rephrase the question, What if we did find life like on earth on another planet, Would that rule out the supreme being? I think the question the OP is posing is one for the creationism/ID forum not planets IMHO

It would be impossible to have an Earth-like planet with a breathable atmosphere without plant life, since it is plants that release oxygen. Without plants, all free oxygen would eventually react with other elements and disappear from the atmosphere.

But, I see no reason why not there could be a world with only plant life and no animal life.

We are just a drop in the ocean in this universe. I think we all know that now. It wouldn't matter if Earth isn't there tomorrow, the universe would still continuse to exist.

It would kind-of be cool to find life on another planet like ours. We would be able to see the differnce and imagine what could have been. Even though we find one. Probably be life years away in another galaxy...

Originally posted by djohnsto77
It would be impossible to have an Earth-like planet with a breathable atmosphere without plant life, since it is plants that release oxygen. Without plants, all free oxygen would eventually react with other elements and disappear from the atmosphere.

But, I see no reason why not there could be a world with only plant life and no animal life.

Then where would the carbon dioxide come from without aerobic respiration?

Originally posted by fiftyfifty
If we discovered a planet which was very similar to ours ie, plenty of surface water, a breathable atmosphere, similar surface temperatures, plantlife and around the same age, BUT there was no biological life other thatn plantlife, what conclusion could we come to about it? Would it give further evidence to us being unique and possibly the creation of a supreme being?

Then I'd run like buggery, because you NEED animals to eat the plants - no animals, ergo then something is keepin the plants in check, and if that's a plant that eats other plants, well...

Now, if you'd have said "Earth like planet filled with animals, but the highest was like a neanderthal" then I'd say we'd probably move in and make it home, killing off the neanderthals as we go, as humans are generally wont to do.

Originally posted by Johnmike
Then where would the carbon dioxide come from without aerobic respiration?

Is fire too obvious an answer?

I think the spirit of the question posed to start the thread was more towards what if we found a planet with conditions that could support human life.

This planet would have to have a pre-existing ecosystem as mentioned to create the oxygen, but what if there were no high level animals evolved as yet. (Say Earth before the Dinosaurs).

The problem in any case is distance, even if its possible to observe a planet with such conditions, we are a long way off having the technology to transport people to even the nearest star systems.

[edit on 19-8-2007 by Kano]

Originally posted by Kano
Is fire too obvious an answer?

Well then, what would you be burning?

Originally posted by Johnmike
Well then, what would you be burning?

The plants? In an oxygen rich environment they would burn like mad.

Volcanoes also spew out large amounts of CO2.

Plants do need bacteria and microbes to survive though, as they need to break down the dead organic matter and convert it into something new plants can use to grow. Plants by and large don't need animals for such mundane things as creating CO2 or eating them to keep them in check.

Originally posted by Kano
The plants? In an oxygen rich environment they would burn like mad.

I'm pretty sure that burning plants wouldn't be enough to feed all the others. Lifetime photosynthesis would probably use more CO2 than one burning plant.

Originally posted by Kano
Volcanoes also spew out large amounts of CO2.

I don't think that's renewable, but for all I know, it could last a while. I have no idea here; you probably know more than I do.

Originally posted by Kano
Plants do need bacteria and microbes to survive though, as they need to break down the dead organic matter and convert it into something new plants can use to grow. Plants by and large don't need animals for such mundane things as creating CO2 or eating them to keep them in check.

I guess there could be aerobic bacteria and whatnot as well. They could do the trick.

Plants use aerobic respiration too. At night, they release carbon dioxide. Plus, all the non-photosynthesizing parts such as the roots always do.

And as Kano said, there most likely would be something breaking down the dead matter, releasing co2.

[edit on 8/20/2007 by djohnsto77]

[edit on 8/20/2007 by djohnsto77]

we would exploit earth for what it's worth faster than E.T. can exploit it, and then move there and do the same..

My Opinion

A world with everything similar to earth but with no animals hmmmm.

Well maybe the plants are sentient and can walk around and eat other sentient

and non sentient plants?

We could send robots to check out what kind of weird diseases and organisms

are there and thoroughly test the bacteria, parasites etc to study whether

humans would be suited to inhabiting the planet.

I think it would be easier just to find a planet close to a similar sun and seed

it with earth organisms (terraform) the place.

but thats just my opinion

The atmosphere would never be breathable right off the bat - too eons for our atmosphere to develop to this point, and it is intrinsically connected to all life on the planet.

Best you could hope for is an atmosphere of comparable pressure that is not toxic to us (so we only require breathing apparatus and not environment suits), comparable gravity and heat range. Then that would be the easiest place off this planet to set up and live.

But IMHO that is really pushing it, may as well just look after the one we've got.

On the other hand - if were not that special and life more or less follows the same lines with the given parameters we live within, then who knows? Maybe every time an Earth sized planet is this distance from a sun size star they are all the same, we may strike it lucky and arrive 50 years after they wipe them selves out with whatever weapons they used.