When you came across an “alien planet” on reading material, the first thing that would probably come into your mind is a literal world full of aliens or an alien habitat. However, the “alien planet” is not what you think it is. Alien planets or exoplanets that are excluded from the solar system, which orbits other stars.
Some exoplanets are in similar size to our very own planet, Earth. Not all of us may know, but there are many more planets other than the planets included in our solar system, way more than the stars in the galaxy. These alien planets can be in the Milky Way galaxy’s small, far away areas, millions of lightyears away from us.
How Would You Know if an Alien Planet Is Habitable?
Earth is the only livable planet discovered, but scientists are trying their best and testing their luck in finding a habitable planet like the Earth. Scientists say that some alien planets or exoplanets could be more livable than Earth. These planets could cater to life better than our life here on Earth.
Researchers have been looking for different alien planets that might be habitable. These planets must be terrestrial planets like the Earth, and they must revolve around yellow and orange dwarf stars.
Yellow dwarf stars like our Sun have a lifespan of 10 billion years, while orange dwarf stars could last longer with a lifespan of 20 to 70 billion years. An orange dwarf star’s lifespan could give the planet enough time to evolve and develop into a conducive planet for living.
To cater life better than Earth, the alien planet must also be 10% bigger than Earth’s size. This size would help retain the heat in the planet’s atmosphere, and a giant planet would also mean stronger gravity. The planet’s temperature is also a criterion for being a habitable planet.
The exoplanet warmer than Earth would be great in flourishing biodiversity on the planet.
Exoplanets That Could Support Alien Life
As of now, 24 planets are habitable and can most likely support alien life. Below is the list of some livable planets that could sustain life.
Kepler 186f
Kepler 186f is the first exoplanet that was discovered that is a similar size to Earth. This planet was discovered orbiting in the habitable zone of a star like our Sun. Kepler 186f is presumably a rocky planet that is 10% larger than Earth. It is located 490 lightyears away from our planet.
Gliese 581g
This planet is a huge rocky planet that is three times bigger than Earth’s size. According to the researchers, this exoplanet has the highest probability of supporting alien life. Gliese 581g is found orbiting in the middle of its star’s habitable zone and is 20 lightyears away from the Earth.
Gliese 667Cc
Gliese 667Cc is an exoplanet orbiting for approximately 28 days on a red dwarf star’s habitable zone. This planet is said to be bigger and heavier than Earth for 4.5 times. Gliese 667Cc is located 22 lightyears away from our planet.
Kepler 22b
Kepler 22b is the first planet that was discovered in the habitable zone of its host star. Although this planet is double the size of Earth, its host star is believed to be almost the same in size and temperature as our Sun.
This planet’s temperature is approximately 22 degrees Celsius, but its composition is yet to be discovered. Kepler 22b’s star system is in the constellation Cygnus, 600 lightyears away from the Earth’s Sun.
HD 40307g
In the habitual zone of the dwarf star HD 40307 lies the potentially habitual alien planet HD40307g. HD 40307g is one of the six planets orbiting this dwarf star. This exoplanet is 90 million kilometers away from its host star, almost half the Earth’s distance, and the Sun, 150 million kilometers.
HD 40307g, determined to be a “super-Earth,” is located almost 42 lightyears away from our planet Earth.
Tau Ceti f
Tau Ceti f is also determined to be a “super-Earth.” This planet is 6.6 times bigger than Earth, orbiting on the outer edge of the habitable zone of its host star. This alien planet is believed to be the exoplanet, which orbits a star like the Earth’s Sun, which has the most potential in supporting life.
If this planet’s atmosphere could trap the right amount of heat, Tau Ceti f could be a habitable exoplanet.
K2-18b
K2-18b is thought to be either a rocky planet resembling Earth or an icy planet with significant water concentrations in its interior, according to scientists. Because its red dwarf star is much cooler and smaller than our Sun, the planet is much nearer to its star than our planet is to the Sun, but it only absorbs slightly more radiation.
Researchers concluded that the planet’s temperature is close to Earth’s — anywhere between minus 99 and 116 degrees Fahrenheit. Because K2-18b is the only documented planet outside of the solar system with an atmosphere, water, and a temperature range that may support liquid water on its surface, it’s a big deal.
On the other hand, the hydrogen-rich atmosphere appears to create a dense gas envelope, which would make any species on K2-18b very different from that on Earth.
GJ 357 d
TESS led astronomers to find this planet, which has a mass of 6.1 times that of Earth and orbits a small star quite closely.
The planet is on the border of its star’s habitable zone, receiving around the same stellar energy levels from its star as Mars receives from the Sun. If GJ 357 d has a dense atmosphere, which would require more research, it may trap heat enough to warm the planet and permit liquid water to exist on its surface.
However, if the planet has no atmosphere, its surface temperature would be around -64 degrees Fahrenheit, much below the freezing point of water.
Kepler-452b
Kepler-452b orbits a sun-like star and completes its orbit every 385 days, unlike many other exoplanets in habitable zones. However, a follow-up analysis published in 2018 concluded that the planet’s discovery could have been a false alarm. Unfortunately, Kepler-452b is almost 1,400 lightyears distant, making further research impossible.
Ross 128 b
Ross 128 b is most probably a rocky planet with a temperate climate, according to a 2018 examination of compounds in the chilly, dim red dwarf star — and its temperatures.
So far, it appears to be suitable for daily use. It’s an excellent target for additional research because it’s the second-closest temperate planet to Earth. Meanwhile, if you want to learn about the constellations that are visible with the naked eye, open the given link.