NASA discovered another 7 Earth-like planets
Astronomers have found seven Earth-sized planets orbiting the same star 40 light-years away, according to findings announced by the National Aeronautics and Space Administration (NASA).
The exoplanets were all discovered in tight formation around an ultracool dwarf star called TRAPPIST-1. While all the seven could potentially support liquid water on the surface, only three of them are within the conventional “habitable” zone where life is considered a possibility.
“This discovery gives us a hint that finding a second earth is not a matter of if but when,” said Thomas Zurbuchen, Science Mission Director at NASA.
This comes as the greatest discovery made so far using a telescope called Spitzer.
What is an exoplanet?
An exoplanet or extrasolar planet is a planet that orbits a star other than the Sun. The first confirmed detection of an exoplanet was in 1992.
Exoplanets are discovered by indirect techniques of detection, mainly by radial velocity measurements and transit monitoring techniques.
More than 3,500 confirmed exoplanets are listed in the Extrasolar Planets Encyclopaedia. Most of them were detected by Kepler, a space observatory launched by NASA in 2009.
Are there any “Earth twins”?
With particular interest astronomers have been looking exoplanets that may potentially support life.
For a planet to be habitable, its distance from its star must allow temperatures that are mild enough for liquid water to pool on its surface.
In July 2015, NASA’s Kepler space telescope spotted the first most Earth-like alien planet – a world that was called Kepler-452b. It lies 1,400 light-years away, and is slightly bigger than our own. It likely possesses a thick atmosphere, lots of water and active volcanoes.
In August 2016, scientists announced the discovery of another planet that they said might hold the ingredients that could make it suitable for life. The planet circles Proxima Centauri, the smallest member of a triple star system known to science fiction fans everywhere as Alpha Centauri. Just over 4 light-years away, Proxima is the closest star to Earth, besides our own sun.
Overall, there are several dozens of potentially habitable exoplanets. But evidence of any extraterrestrial life has yet to be found.