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Has any form of life been discovered on a planet? There are billions and billions of stars and galaxy's and planets, and we still have not discovered life, why not? If we did how would we even communicate if they are beings?
Question Date: 2005-05-07
Answer 1:

No, although there is some partial evidence of possible microbe fossils from martian rocks. You are right in that there are likely hundreds of billions of planets in our galaxy alone. However, until the last month, there has not every been direct observation of any planet outside the solar system. There are about 160 known planets which have been detected by the wobble the put on the stars they orbit and this has been the most common way to find them. Beyond that, there is very little known about any of the planets.

In our solar system, the prospects for like like exists on earth is pretty low, i.e. buried microbes on Mars or Europa (a moon of Jupiter), but other kinds might exist and we simply don't know what to look for. Most scientist think that life is likely on favorable planets, and there are likely to be millions of such in the galaxy, but for us to communicate, both civilizations need to be interested at the same time and somehow manage to find common means to communicate.

Although old TV from 50 years ago is now visible in a 50-light year diameter sphere, no one knows the likelihood of a earth like planet in that sphere and if they built the large radio telescopes needed to see "The Lucy Show". (We haven't done so yet). Moreover, our modern communications is now millions of times more efficient, making it that much harder to interpret. If 'they' do the same thing, they might be millions of year ahead or behind us and even 50 years ago, we could not have seen a thing. At some point it will make sense for us to do a thorough search, but currently our instruments are just not up to the task.

Answer 2:

Well, we have discovered life on earth, I think we can be sure of that. At least I think I'm alive. I can feel my heart beating.

But no, as far as we have observed, we are alone in the universe. That said, many astronomers and biologists strongly believe that there might be life on other planets that we simply have not encountered yet.

The difficulty, then, lies in the incredible size of the universe. So far, even with our most advanced technology and our most powerful telescopes and methods, we have only been able to detect planets outside our solar system by gravitational interactions with their stars and by observing their stars dimming when eclipsed by their planets. Because large mass makes gravity-detection easier, we have so far the technology only to detect planets of Jupiter-size and larger, and Jupiter is as far as we know hardly a place for life. So far, I do not believe we have observed any smaller worlds that are not orbiting pulsars. Until we find worlds of roughly the size of Earth, we do not expect to see evidence of life.

As for communication, again, the universe is awfully huge. Essentially, in order to communicate anything at all, we have to encounter another form of life that is itself attempting to communicate with us. Having only one data point to go on (ourselves), we do not know how diverse the universe is in terms of sentient life capable of communicating. However, even if we can in principle figure a way to decode their message (or they decode ours), we run into a response-time problem: information cannot travel faster than the speed of light, so even if we were talking to life orbiting a nearby star, it would take years for our signal to get there - and years for their response to come back.

Answer 3:

As of now, there has not been found any kind of life in other planets. In spite of the fact that there are millions of galaxies, and millions of suns, still we do not know if there are any planets with the conditions to keep any kind of life. The scientists do not agree yet about existence of life in other planets. Some of them think that there is life in many planets, some do not. By the way, in our galaxy, the earth is the only planet with life.

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