What are exoplanets? : Explained
Are you aware of the mind-boggling concept of exoplanets? Have you heard of Kepler-452b and Gliese 667Cc? If you do not know these names, this blog post is for you.
What is an exoplanet?
A planet which is outside the solar system is known as an exoplanet. Its other name is extrasolar planet. The first possible evidence of an exoplanet was found in 1917. But it was not recognized by the astronomers because of lack of evidence. They were first confirmed and detected when the space agencies noticed them in 1992.
Finally, in 2002, the new species of the mysterious planets was named ‘The exoplanets’ and was globally accepted by different space agencies. There are four types of exoplanets which are Terrestrial planets, Neptune-like planets, Super-Earth-like planets and Gas Giants.
Methods of detection
Exoplanets are detected using several satellites, probes, etc. They are also detected using methods like direct imaging, microlensing, transit observations, astrometry and the Wobble Method also known as radical velocity.
It is a very difficult task to detect exoplanets because of their small size, the presence of other interfering activities like stellar activity, which is caused by the magnetic fields and rotation of exoplanets, their dimness and their distance from the Earth.
Astronomers have discovered several exoplanets despite the challenges. 5483 confirmed exoplanets have been discovered from 4082 planetary systems with 924 systems having more than one huge exoplanet. Most of them were observed and discovered by the well-renowned Kepler Space telescope. Some of the discovered exoplanets are Gliese 667 Cc, Kepler – 69c, Kepler -186fs, Kepler-22b, Dimidium, WASP-12b, Awchali, etc.
Why search for exoplanets?
Mostly, exoplanets are not habitable, only Kepler-45lb is habitable. So, why do astronauts keep on looking for these new species of planets? So we can find another planet that can support us if need arises. And if this happens, it could change human and space history forever.
Photo credits- NASA