According to NASA’s Exoplanet Exploration page, scientists have discovered more than 4,000 exoplanets since the first such planet was verified to be circling a sun-like star in 1995. (opens in new tab). The NASA Kepler space observatory, which was deployed in 2009 to determine the prevalence of Earth-like planets throughout the Milky Way galaxy, is responsible for more than half of these findings.
Astronomers have long dreamed of finding the first real “alien Earth,” and recent exoplanet discoveries have revealed that tiny, rocky worlds like our own are common throughout the cosmos.
A planet must be relatively tiny (and hence rocky) and orbit in the star’s “habitable zone,” which is broadly defined as a region where liquid water may exist on a planet’s surface. When telescope technology advances, other elements will be taken into accounts, such as the planet’s atmosphere and its parent star’s level of activity.
Here are the ten planets that are most likely to have extra-terrestrial life that we are aware of:
The first Earth-sized exoplanet discovered in the habitable zone of its host star is Kepler-186f. The extra-terrestrial Planet, which is 490 light-years away from Earth, is just 10% larger and probably definitely made of rocky material.
It is a contentious discovery, this planet. Although it was found in 2010, getting it verified has proven to be challenging. Gliese 581 is still regarded as the leading contender for extra-terrestrial life by the University of Puerto Rico at Arecibo. If verified, this rocky planet is two to three times as large as Earth and is located around 20 light-years from the sun. In the constellation Libra, it revolves around its parent star Gliese 581 every 30 days or so.
Gliese 667 cc
Gliese 667Cc, another “super-Earth,” is a nearby object, only 22 light-years distant in the constellation Scorpius. The planet takes 28 days to complete one circle of its parent star and is at least 4.5 times larger than Earth. The parent star, GJ 667C, is a triple-star system. The star is an M-class dwarf star with a mass that is roughly equal to that of the sun.
Kepler-22b is larger than Earth, yet it orbits a star that is similar to the sun in terms of size and warmth. Given that Kepler-22b is 2.4 times the size of Earth and that its greenhouse effect is comparable to that of our planet, it is projected that its surface temperature is 72 degrees Fahrenheit (22 degrees Celsius.) Its star system is located in the constellation Cygnus, 600 light-years from the sun.
Super-Earth HD 40307g orbits peacefully within its parent star’s habitable zone. It is found in the constellation Pictor, 42 light-years from Earth. Future telescopes could be able to look at its surface because it is so nearby. Just over half of the 93 million miles (156 million km) distance between the Sun and Earth, it circles its parent star at a distance of 56 million miles (90 million km) (150 million kilometers.)
HD 85512b was one of 50 planets found by the High Accuracy Radial Velocity Planet Searcher instrument, or HARPS, in Chile, and was first reported in 2011. This planet has a mass that is around 3.6 times that of Earth. It dwells in the constellation Vela, around 35 light years from the sun (the Sail). One day, it may be possible to determine whether there is water on its surface, say researchers.
Tau Ceti e
The distance between Earth and the planet candidate Tau Ceti e, which was discovered in December 2012, is only 11.9 light-years. This planet is at least 4.3 times as large as Earth, making it a “super-Earth.” Tau Ceti e might either be a moderately hot planet suitable for basic life or an extremely hot planet like Venus, depending on its atmosphere.
Gliese 163c is in a grey area because of its bulk. The planet, which is seven times as massive as Earth, maybe a dwarf gas giant or a very huge rocky planet. Gliese 163c, located 50 light-years from Earth, revolves around its faint planet star every 26 days. Dorado is the constellation that contains its parent star.
According to at least one research, Gliese 581d could contain a dense atmosphere of carbon dioxide. It is the sister planet of the similarly possibly habitable Gliese 581g, which is nearly seven times as large as Earth and circles a red dwarf star. Gliese 581d is only 20 light-years from Earth, making it almost a neighbor.
Tau Ceti f
Like its twin Tau Ceti e, Tau Ceti f is a super-Earth candidate, although it orbits rather near to the outer border of Tau Ceti’s habitable zone. Tau Ceti f is at least 6.6 times as large as Earth and, if its atmosphere traps considerable quantities of heat, would be suitable for life.
Even though the future James Webb Space Telescope (JWST) has the potential to investigate the atmospheres of exoplanets, its results might be misinterpreted. Sophisticated life may have a higher probability of evolving on worlds that are tilted on their axes.
The ten planets listed above are Earth-sized and located in their stars’ habitable regions. This indicates that they are just far enough away for liquid water to be present on their surfaces.