Extra terrestrial life means life outside earth.Our scientists believe the existence of life on other planets but they have not yet discovered any such planet having life.The science of extra terrestrial life is known as “EXOBIOLOGY”.The search for extra terrestrial intelligence started in mid 20th century.Many tried to contact extra terrestrial life but no one has succeeded.Some people argue that having the attention of extra terrestrial life may pose a danger to life on earth.
Famous scientist “STEPHEN HAWKING” said that he wants to find aliens before they find us. Our scientists found an interesting fact that life on Mars may be possible but research has been going on. NASA plays an important role in extra terrestrial life search.There are projects for an indirect search for extra terrestrial life like SETI(Search for Extra Terrestrial Intelligence).These projects monitor the galaxy for signals from other planets. The nearest known exoplanet to is “PROXIMA CENTAURI” located 4.2 light years away from earth.
NASA has already discovered more than 5,000 planets that could sustain life and many more are likely to be found and they are planning to use some of the world’s most advanced technology to produce a road map of space.Today’s modern telescopes can look at hundreds of stars and tell if they have one or more orbiting planets and they can even determine if the planets are the right distance away from their host star to contain liquid water, which is the key ingredient to life as we know it.
The possibility of extra terrestrial life was first discussed in “Paradise lost” by John Milton in the 17th century.Nearly 2000 planets have been discovered by the scientists.Most of these discoveries are made from telescope.Some of the closest known planets to are earth kepler-22b,kepler-69c,kepler-62f.
DRAKE EQUATION: The Drake equation is a probabilistic argument used to estimate the number of active, communicative extraterrestrial civilizations in the Milky Way galaxy.