Re: Do scientists believe there is life out in space.

Well I do. But what I _believe_ and what I _know_ are different. I, and many other scientists guess that life is likely to occur in other places than just the Earth, but we don't have any hard evidence -- yet. The best evidence so far is that for the existence of fossil Martian microbes in a meteorite recovered from Antarctica. That evidence is, I think, reasonably good, but not good enough to establish such an important result. Needless to say, there are a lot of research groups working in this area, so we may be able to get more support for this hypothesis, or, more likely alas, eliminate it as a serious contender, over the next year or two. Here are some references. The last is kind of heavy duty.

http://www.fas.org/mars/marslife.htm
http://www.seds.org/~spider/spider/Mars/mmetlife.html
http://cass.jsc.nasa.gov/lpi/meteorites/alhnpap.html

Various scientists have speculated (speculation is the first step in the scientific path to knowledge) that habitats suitable for developing life may now exist or in the past existed on Mars, Europa, Titan, and other solar system bodies. NASA has lots of big plans to take closer looks at these places, see

http://eis.jpl.nasa.gov/roadmap/site/quests.html

In the last couple of years, planets have been discovered around other stars. So far, these have all been giant planets, because they are the only kind we can detect at present. But there _may_ be planets more like earth too. Do they have life? It's very hard to tell right now. One way to try to figure this out is to build a telescope that can see earthlike planets in orbit around other stars, and study their atmospheres. Earth has an atmosphere very different from any other planet in our solar system. The reason? Life. Life has changed our atmosphere to produce one in which a very unstable gas, oxygen, is plentiful. If you were to remove life from Earth, all the oxygen would soon disappear. So if we were to find a distant, earth-type planet with lots of oxygen (and maybe methane and/or ozone too, which are other possible markers for life), then we might conclude that there must be life on that planet. Only problem is that a telescope that can do that does not yet exist. But it may be possible, with a great deal of effort, to build one in space in about 20 years. Both NASA and ESA are thinking about just how to do this. NASA's idea is called the Terrestrial Planet Finder. You can find more at:

http://origins.jpl.nasa.gov/

A cheaper way to search, but, perhaps, riskier, is to go for broke and look for intelligent aliens with advanced technology. At present, the very most conspicuous feature of the Earth that labels it as a place with life is the radio emission produced by our TVs, radars, etc. So some folks are looking for artificial electromagnetic signals coming from other sun-like stars. As I write this, for example, the system I use is listening to a G star 59 light years away at frequencies between 1625 and 1645 MHz. We are trying to cover 1200 to 3000 MHz for the closest thousand sunlike stars, a project that will take several more years to complete. There are billions and billions of sunlike stars in our galaxy, however, so patience is advisable. Of course, it may be that there are no other civilizations, or at least none that we can find. To go from speculation (hypothesis) to knowledge requires solid evidence, so we'll just have to keep looking until we can devlop solid, reproducible evidence for an artificial signal of extraterrestial origin. You can find out more about this kind of work (SETI) at http://www.seti-inst.edu/