From the dawn of time, humans have been looking up to the stars, wondering if we were alone in the universe or if there are indeed other habitable exoplanets like ours out there.
It has recently been discovered that there is at least one Earth-sized planet in the habitable zone of a distant star, and more are being discovered all the time.
Not only is this an intriguing prospect, but there may also be an entire universe full of Earth-sized planets.
Since the 1990s scientists have discovered more than 4,000 “exoplanets” — although only a handful of these would possibly be habitable.
It has been discovered that these said exoplanets orbit a variety of different stars from M-type stars (also known as red dwarfs) to sun-like G-type stars such as Tau Ceti.
Finding habitable planets involves finding “habitable zones” around stars where the conditions are optimal for life. That is to say, these planets are not too close, as they’ll be too hot, and not too far away from the star, as it’ll be too cold to sustain life.
The first main ingredient for a suitable planet is water. In the Habitable zone around a star the planet would need to be the right distance and temperature for liquid water to exist.
This water would of course need to be able to pool. A rocky planet would be ideal for this.
So, the ideal candidate would be an Earth-sized, rocky world that is nestled in the habitable zone of a star.
On 4 November 2013, astronomers reported, based on Kepler space mission data, that there could be as many as 40 billion Earth-sized planets orbiting in the habitable zones of sun-like stars and red dwarf stars within the Milky Way galaxy.
We have compiled a list of suitable exoplanets from the available data that are nearest — up to 50 light-years — from our solar system.
This list consists of the nearest planets and starts with closest planet and increases in distance up to 20 light-years from Earth.
Proxima Centauri b: This exoplanet is orbiting the habitable zone of the red dwarf star Proxima Centauri, which is the closest star to the sun. This planet is located 4.2 light-years from Earth.
Barnard’s Star b: This exoplanet is a “super Earth” candidate and ice planet that orbits Barnard’s star in the Ophiuchus constellation. This planet is 5.958 light-years away from Earth.
Ross 128 b: This rocky exoplanet has been confirmed to be Earth-sized and orbits within the habitable zone of the Red Dwarf Ross 128 at a distance of 11 light-years from Earth.
Luyten b: The Luyten b exoplanet is most likely also a rocky planet. It sits in the habitable zone of the nearby Red Dwarf Luyten’s Star. This one of the most Earth-like planets ever found and is 12.2 light-years away.
Wolf 1061b, Wolf 1061c and Wolf 1061d: These planets orbit inside the habitable zone of the Red Dwarf star Wolf1061 in the constellation Ophiuchus and are all about 13.8 light-years away.
Gilese 876 d: This exoplanet is approximately 15 light-years away from Earth in the Aquarius constellation. At the time of its discovery it had the lowest mass of any known extrasolar planet besides the pulsar planets orbiting PSR B1257+12.
Gilese 682b: This planet is actually a red dwarf. It is dim with a magnitude of 10.95 and thus requires a telescope to be seen. It is located in the constellation of Scorpius, near the bright star Theta Scorpii. It has two candidate planets, one of which is in the habitable zone. It is located 16 light-years away from Earth.
Gilese 832c: This is an extrasolar planet locate in the Grus constellation and orbits the star Gilese 832 which is a red dwarf. It is located 16.6 light-years away.
Eridani b, Eridani c and Eridani d: These planets are actually stars that are located approximately 19.71 light-years away from Earth in the Eridanus constellation.
Gilese 581 e: This is an extrasolar planet orbiting within the Gilese 581 system. It is located within the Libra constellation and is about 20 light-years away from Earth.
Although the prospect of finding Earth-like planets is exciting and the discovery of such planets brings us closer to understanding the ins and outs of the universe, it will most likely be a while before further exploration will be possible regarding these planets.
Scientists definitely have their work cut out for them in the future, but that will not stop us Earth-dwellers from looking up and contemplating the stars.
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