have any known devs told belief in aliens?

Use the Internet, that's what it's there for. :)

I think any reasonable scientist would assert that life at some level, whether it's the simplest prokaryotic bacteria to the most complex multicellular intelligent lifeforms or some type of life we have yet to discover, most likely exists on other planets. There's a growing amount of evidence to support that assertion. We've confirmed that nearly all of the conditions that are required for life exist, or have existed, on other planets, including Mars. There is some fossil evidence (still being analyzed and debated) that bacteria may have existed on Mars millions of years ago. Astronomers have detected the existence of planets around other stars that are in the habitable zone and may have conditions friendly to life.

New experiments are also being devised to detect intelligent life on other planets. For example Project Phoenix is currently under way to find planets that lie within the habitable zone of their stars and that also have absorption spectra consistent with chemicals which may indicate the existence of advanced civilization. This research will be tied in with Seti and other alien-life search projects.