Teegarden's star b, discovered in 2019, according to a study from The Planetary Habitability Laboratory, is the most likely habitable exoplanet, with a mind-blowing ESI of 0.95. Only 12 light years away from Earth, it orbits Teegarden’s star, an ultra-cool M-type red dwarf star that, like most red and brown dwarfs, emits most of its energy in the infrared spectrum. 

Scientists have observed that Teegarden’s star is very “quiet” compared to most red dwarfs - notoriously prone to erupting in massive flares, while no flares have been observed from Teegarden’s star, making finding Teegarden’s star b and c a lot easier. Additionally, Teegarden’s star b’s size and mass are almost identical to Earth’s, both less than 5% larger than Earth’s. However, Teegarden’s star b has an orbit of only 118 hours or 4.9 days and is tidally locked, meaning that the planet does not spin on its axis or have night and day, and one side of the planet always faces the star. I believe that being tidally locked is probably the biggest bummer since even though adjusting to a  year that lasts only 4.9 days will be extremely hard, if the planet is tidally locked it could mean only the side of the planet facing the sun is habitable!

Kepler-1649c, discovered only in 2020, has an ESI of 0.92, and it’s only less than 10% larger than Earth and 300 light years away. However, Kepler-1649c has an orbit of only 20 days around an M-type red dwarf star, receives only 75 % of the light Earth receives from the sun, and is most likely tidally locked.

Proxima Centauri b orbits the closest star outside of our solar system to Earth and is the closest known exoplanet too, just 4 light years away, probably the first exoplanet we’ll figure out how to get to. However, astronomers had a hard time finding it and it was only discovered in 2016, due to it being too close to its star, Proxima Centauri. Proxima Centauri is a red dwarf star, so Proxima Centauri b has an orbit of only 11 days, is tidally locked, and has no axial tilt (if you drew a line through the center of Proxima Centauri it would be completely straight, unlike Earth’s). Also, the very short distance from Proxima Centauri b to Proxima Centauri means it is affected by solar flares, brief eruptions of high-energy radiation from Proxima Centauri’s surface, and could partially lie outside of the habitable zone during part of its orbit. However, it has a mass of 1.17 Earths and a size of 1.27 Earths, which would be easier to adjust to. So overall, it wouldn’t be the best choice, but it’s the closest choice, so it has an ESI of 0.87.

Another planet closer to Earth but nowhere close to being one of the best planets to foster us, Trappist-1e is only 40 light years away orbiting a very dim M-type red dwarf star. The planet has an orbit of only a shocking 146 hours or about a week. If it wasn’t most likely tidally locked, the seasons on Trappist-1e would be crazy - imagine a little less than 2 days of summer, spring, autumn, and winter! Also, Trappist-1e is 40% smaller than Earth, so maybe only a small part of the population could live there while other humans settle on larger planets further away from Earth and Trappist-1e. It is given an ESI of 0.85.

Kepler-442b has an ESI of 0.84 because it is 33% larger than earth and not tidally locked. However, it has an orbit of only 112 days and is 1,115 light years away. According to a study published in 2021 by the Monthly Notices of the Royal Astronomical Society (Covone et al. Efficiency of the oxygenic photosynthesis on Earth-like planets in the habitable zone), Kepler-442b may be able to receive enough light and radiation from its sun to sustain a large biosphere, making it even more likely to be able to sustain life.

Kepler-452b, discovered in 2015, this planet has an ESI of 0.83, due to its many similarities with the earth it has. These include a year of 385 days, only a few weeks longer than Earth’s, most likely a rocky terrain, a star called Kepler-452 which is also, a G-type main-sequence yellow dwarf star like our sun, though roughly 1 billion years older, and most likely not being tidally locked. Kepler-452b is also 60% larger than earth and has a mass of roughly 5 Earths, which is probably going to be helpful in the future when the human population grows very big and things start to get too packed on Earth. However, Kepler-452b is over 1,400 light years away and its atmosphere and composition are still unknown.

Gliese 667cc is quite an interesting planet - do you notice how the name ends in “cc” instead of one letter like Kepler-1649c? That’s actually because Gliese-667cc is part of a triple star system, meaning it includes the three stars Gliese-667 A, B, and C, with Gliese-667cc orbiting the latter. But don’t get your hopes too high, unfortunately, even though there are three stars in the solar system, the planet won’t have a Star Wars-type sunset, though the star will appear bigger in the sky than our sun because Gliese-667cc has an orbit of only 28 days and is much closer to its star. Gliese-667cc is most likely not the most ideal planet though, definitely being tidally locked and having a mass of 3 times that of Earth, however, it has an ESI of 0.80 because it is confirmed to be rocky and it’s only 22 light years away so it will be easier and faster to get to.

Kepler-69c has two main advantages - large size & a similar star to our sun, and the only disadvantage is how far away it is. Discovered in 2013, Kepler-69c is a whopping 2,707 lightyears away, but scientists have been drawn by some features that could make a transition from Earth to Kepler-69c more comfortable. For a start, Kepler-69c’s star is a G-type yellow dwarf, like our sun, and its orbit of 242 days would probably cause fewer months in the calendar, but it's not as low an amount as most of the other planets in their star’s habitable zone. Also, it is 70% larger than Earth, which, depending on the way you look at it, could be an advantage or a disadvantage. Kepler-69c’s ESI is unknown.

A pretty reasonable option to live in, Kepler-22b is about 600 light years away orbiting a G-type yellow dwarf star very similar to our sun and an orbit of 290 days similar to Earth. It’s 2.4 times larger than Earth but its mass is a colossal 36 times larger than Earth’s, meaning it has 36 times more matter! Additionally, Kepler-22b is most likely not tidally locked. Astronomers have given it an ESI of 0.71, but I think it’s one of my favorite exoplanets on this list - I would love to go there on holiday!

Kepler-62f has a similar size and mass to Earth, being only 40% larger than earth and having 2.8 times more mass. Kepler-62f’s star is a main-sequence K-type orange dwarf star slightly smaller and cooler than our sun, so Kepler-62f could potentially have liquid water on its surface as the year lasts only 267 days. It was discovered in 2013and is pretty far away from Earth - 1,207 light years away. It has an ESI of 0.68.