Habitable Zone
In search for alien life astrobiologists follow a simple rule:"Where there's water, there might be life." When we look to the night sky, we can see a myriad of stars. Many of those stars are orbited by planets. The question is: where to look? The answer is: habitable zone (HZ). Try to imagine HZ as belt of space in which water can exists in liquid state. To estimate stars HZ we use Stefan-Boltzmann equation. We simply put stars luminosity into equation and do the calculations. However we don't get exact HZ, but rather estimated HZ. It is so, because Stefan-Boltzmann equation applies to completely black surfaces and as we know, planets aren't black. If we calculate HZ for Sun, we get some interesting results. (1) Suns HZ spans from 0.7 x Earths orbit to 1.3 x Earths orbit. (2) Venus lies in inner edge of HZ at 0.72 x Earths orbit. (3) Mars is beyond HZ (1.52 x Earths orbit).
Venus
Let us take a closer look at Venus. It lies in Suns HZ, but as we all know there is no life on Venus. The fact is not surprising, isn't it? Maybe a little, let me show few characteristics
Venus mass = 0.815 Earths
Venus surface = 0.902 Earths
Venus volume = 0.857 Earths
Venus radius = 0.949 Earths
and few more. It looks similar doesn't it?
"Instead of a lava-strewn wasteland, Venus might have been a steamy-jungle world with lush vegetation and perhaps a diversity of animal life. So what went wrong?" [1]
Indeed, what went wrong? Well there are two theories, but that's another story. If your interested just check the reference.
Europa Moon
I suppose the Jupiter's moon is quite well known. The interesting fact about Europa is that even though he lies far beyond Suns HZ and he is not Earth-like many scientists believe that there is subterranean ocean on Europa.
Summary
Story of Europa and Venus shows that still we do know little about HZs. I believe that discovery of alien lifeforms is only a matter of time. I can't say when or where it happens, but I am sure that place of this discovery will be surprising.
Q:
Do you think that we discover extraterrestrial life within decade? When?
Ref.:
[1] Life Everywhere by David Darling
I think we won't. There's a bigger possibility that extraterrestrial life will find and destroy or abuse us ;-)
ReplyDeleteI agree with Asia. We can not go to Mars, so how could we discover civilizations in other galactic s? We do not have technology (I think so:)) to do it..
ReplyDeleteHmm, its hard to say.
ReplyDeleteRecently I heard about the scientist who believe that in space are beings similar to us and he warns against the searching and provocation them. What do you think? Maybe first they find us?
As I said in previous post, scientists got weird signals from universe and it lasts for long time. In spite of that I think we don't have so developed technology to discover something like that.
ReplyDeleteSpace exploration is moving veeeery slowly. After the race to the moon things didn't change that much. I think the main reason for it is lack of interest from companies = insufficient funds.
ReplyDeleteYes Piotr, you're right - this scientist was professor Stephen Hawking, famous British theoretical physicist. He warned us not to look for any contact with other forms of life in space. He is a genius scientist and I think he knows what he is talking about.
ReplyDeleteLately I've been reading 'The Martian Chronicles' by Ray Bradbury. It's a book about developing Mars by human wrote in 1950. It's a very interesting vision of how does life in Mars may look like.
I don't think so. Our technology is to weak, space exploration is still very poor ( man on the moon and few pathfinders on Mars). Maybe mankind ( probably USA ) will build base on the moon within decade but this is really big MAYBE.
ReplyDeleteWithin decade? Maybe. In fact it's very hard to estimate when this will take place because it depends on many factors. One thing is certain - we will find extraterrestrial life.
ReplyDeleteI agree with Asia and Szymon that the bigger probability is that if somewhere in galaxy extraterrestrial life exist, it will find us first. But I prefer the version that this being will come with peaceful intentions;)
ReplyDeleteI think that it is not possible. World is facing a economic crisis and space exploration isn’t cheap. Another thing is technology limitation. By the way have you heard about this:
ReplyDeletehttp://www.tvn24.pl/-1,1656658,0,1,zabojczo-szybki-silnik-coraz-blizej,wiadomosc.html
In this decade? No...
ReplyDeleteThere is a bigger possibility that some extraterrestrials would find us first.
Funny thing. If we stood on the nearest (nearest to the Earth) star and took a good telescope to observe our planet, we would see still ancient Egypt civilization.
(hundreds of years light has to came to reach that point).
*print screen’ed*
@Tomasz Frender:
ReplyDeleteso now we have to invent teleportation and we could have a great tool to review our history - just teleport further away to watch earlier times.
and about life: i guess we won't find anything new in the nearest decade. next century maybe?
In decade? No I don't think so. But as Hawkings says travelling to future(but not to past) can be possible so we can go faster there :P
ReplyDeleteAnother option is that extraterrestrial form of life already has found us... :)