Is there life outside our little blue planet?



Mars. Possible evidence of bacteria/life on Mars.

It's now believed that extrasolar planet HD 189733b has carbon dioxide in its atmosphere. It's something like 60 (63?) light years away from us. This brings to the fore a question that Carl Sagan made popular in the 1970s and 1980s: is there life outside of our planet? Odds are that in a universe filled with billions of galaxies that each contain billions of stars, somewhere life has emerged. But we don't know that for certain, so a pioneering science of astobiology or exobiology has started looking into some interesting questions. Planets with oxygen-carbon atmospheres, water and salt are among the most sought after, but since distant planets are difficult to evaluate, most of the work being done is speculation on atmospheric conditions. Some scientists think life has already sprouted on Mars (some even think that bits of mars brought life to Earth) but then declined (some claim it may still exist and a direct chemical test in the 70s was about 50-50 on this, so perhaps it has life now), and some maintain that there's life on some of the moons in our solar system.

Have we been visited?

This is a more contentious subject matter, but I wonder how many people on jsp have observed UFOs. I'm guessing several have, but the explanations are often quite sobering (air balloons, test missles, light/weather effects, hallucination, helicopters, hoaxes). Some people suggest that the ancients were visited by aliens, who gave us technological gifts and taught us things. However, while there are some ancients who believe din UFOs, it's hard to find any thoroughgoing accounts of alien visits

Edit: "how did they get here?" Wormholes are the best current answer out there imo. Kind of weak.

This post was edited by RewtheBrave on Dec 10 2008 02:26pm

I'd be really surprised if there wasn't of all sort across the universe. I'm very skeptical of any visits of extraterrestrial beings visiting earth.

Some people believe that Mars is a future earth. It used to be inhabitable and a meteor sent organic information to earth and life here originated from Martian life (a theory of life starting that is not Abiogenesis). Honestly, I think it is quite vain to think that we are the only life forms in the universe. There are billions of other planets, stars, and galaxies, how could we be the only one?

This post was edited by ChaosDealer73 on Dec 10 2008 02:31pm

I believe in that, without any doubt.

There is no way, that we are "alone" in a place, thats size we cannot even image.

If we start harvesting rudimentary, hardy plant life on the polar caps of Mars, we could slowly transform its atmosphere. 200, 000 years later, who knows? I think you're right to keep an open mind about extraterrestrial life, but nay-sayers will have something to say until we find it (if we can find it)

Well the Drake Equation made it extremly possible there is life outside our soloar system

http://en.wikipedia.org/wiki/Drake_equation

I think it might be a but if wishful thinking when it comes to extraterrestrial life.

We really don't want to be alone do we :/...As it is, I doubt there is anything of significance out there, the conditions that make it possible for life to exist here on earth are extensive.

If we find life...I would expect it to be closer than not to home here on earth. Life will no doubt tend to cluster, conditions which made our position within the galaxy beneficial for life will no doubt offer the same elsewhere as well.

well i guess hes wrong

I personally believe that there is life outside of our planet. "life" doesn't necessarily mean "intelligent" (maybe we aren't that intelligent in the grand scheme of things?) creatures like us, although they might exist too.

I don't really buy into the whole argument that "if they existed, they would have visited us by now." I mean, we exist, don't we? Have we ourselves visited other far-away planets? No, so why should we expect other lifeforms to be able to do it? And even if there is an extremely advanced race of intelligent creatures on a planet somewhere, that have found a way to travel throughout the universe, they might not even know of our existence, or if they do, they might be far enough away that it would take them far too long to visit us anyway.

Is it even physically possible to travel throughout the galaxy, taking into consideration things like possible technology, our lifespans, etc?

I definitely believe that there are other forms of life in our universe, if only microbial. Perhaps even intelligent life has evolved elsewhere (this I am more unsure of, as single cell life evolved fairly rapidly on earth but took billions of years to progress to a multi-cellular format). Also it is pretty doubtful that the technology required to travel interplanetary distances exists anywhere, and without any kind of near light speed travel, or a form of faster than light travel, the distances involved are too great to travel with conventional means. Just look at the Voyager probes. UFOs (and especially things like abductions) are probably non existant.

The most likely contact with any sort of intelligent being would be though radio waves (or other forms of electromagnetic radiation) or mechanical, self replicating probes.