Astronomy

=Are we alone, or is there life elsewhere in the universe?=

Is there life elsewhere in the universe? I'm going to write an essay about it.

There may be no little green men living in our Solar System. However, there are plenty of places where more primitive life might be able to survive. There may be no little green men living in our Solar System. However, there are plenty of places where more primitive life might be able to survive.

Every few years, the red disc of Mars passes particularly close to the Earth, and human observers are afforded an especially good view of the planet that has fascinated mankind since ancient times. We all know that there is life on Earth, but we don't know where it came from. The title question is one that has failed to be answered with a definite response. For 40 years, scientists have conducted searches for radio signals from an extraterrestrial technology, sent spacecraft to all but one of the planets in our solar system, and greatly expanded our knowledge of the conditions in which living things can survive.

The public perception is that we have looked extensively for signs of life elsewhere. But in reality, we have hardly begun our search. Assuming our current, comparatively robust space program continues, by 2050 we may finally know whether there is, or ever was, life elsewhere in our solar system. At a minimum we will have thoroughly explored the most likely candidates, something we cannot claim today. We will have discovered whether life dwells on Jupiter's moon Europa or on Mars.

And we will have undertaken the systematic exobiological exploration of planetary systems around other stars, looking for traces of life in the spectra of planetary atmospheres. These surveys will be complimented by expanded searches for intelligent signals.