Top 10 Most Earth-Like Exoplanets Discovered So Far

#1: Kepler-452b (1.6x Earth Radius, 1,400 Light-Years Away)

Discovered in 2015, Kepler-452b quickly earned the nickname “Earth’s older cousin,” and for good reason. Orbiting a Sun-like star in the constellation Cygnus, this exoplanet is situated comfortably within its star’s habitable zone—the region where liquid water could potentially exist. At roughly 60% larger in diameter than Earth and with a year that lasts about 385 Earth days, Kepler-452b is both familiar and alien. Its host star, Kepler-452, is 1.5 billion years older than our Sun, suggesting the possibility that any biosphere on this planet had a considerable head start over life on Earth. Although no direct evidence of life exists, this timescale opens doors to speculation—what if intelligent life once thrived and vanished here long before we evolved? One of the most fascinating aspects of Kepler-452b is how it might represent Earth’s distant future. As its parent star grows older and hotter, the planet may be experiencing the early stages of a runaway greenhouse effect, not unlike what scientists fear might someday occur on Earth. Studies suggest Kepler-452b could be rocky, with active volcanism and a dense atmosphere. However, its larger size might mean stronger gravity, possibly making it harder for humanoid life to walk upright. Despite these unknowns, Kepler-452b was among the first real contenders in our search for a second Earth, and it remains iconic in exoplanetary studies. What you might not know is that the discovery of Kepler-452b came just weeks before the 20th anniversary of the first confirmed exoplanet, underscoring how far exoplanet science has come in two short decades. While direct imaging and atmospheric analysis remain out of reach with current technology, Kepler-452b continues to inspire scientific inquiry and science fiction alike. It’s a beacon of possibility that invites us to imagine civilizations that could have risen and fallen under the light of another Sun.

#2: Kepler-186f (1.1x Earth Radius, 490 Light-Years Away)

Kepler-186f was a landmark discovery that made headlines in 2014 as the first Earth-sized exoplanet found within the habitable zone of another star. Located about 490 light-years away in the constellation Cygnus, it orbits a red dwarf star much smaller and cooler than our Sun. Kepler-186f is only about 10% larger in diameter than Earth, making it remarkably Earth-like in scale, and it completes an orbit every 130 Earth days. Despite orbiting closer to its star than Earth does to the Sun, the lower energy output of its host star places it squarely within the habitable zone, raising hopes that liquid water might exist on its surface. One compelling detail about Kepler-186f is its position in a system that contains four other planets, all closer to the star, making it a solitary sentinel at the edge of the habitable zone. This setup makes scientists wonder if it could have retained water due to less stellar activity and radiation than its inner neighbors. A hidden gem here is the quiet nature of its host star—low stellar flaring means the planet may not be subjected to harsh radiation, a key factor in retaining a stable atmosphere. While we don’t yet know if Kepler-186f has an atmosphere or what it’s made of, its size and location make it a top candidate for habitability. What few people know is that this exoplanet has inspired not only scientific papers but also speculative art, short stories, and even architectural concepts for human settlements beyond Earth. Though we may never set foot on Kepler-186f in our lifetimes, it represents a powerful shift in our understanding: Earth-sized planets in habitable zones aren’t rare, they’re plentiful.

#3: TRAPPIST-1e (0.91x Earth Radius, 40 Light-Years Away)

One of the most exciting planetary systems ever discovered, TRAPPIST-1 sits just 40 light-years away in the constellation Aquarius. Among its seven Earth-sized planets, TRAPPIST-1e stands out as the most potentially habitable. Slightly smaller than Earth and orbiting in the middle of the star’s habitable zone, TRAPPIST-1e receives about 60% of the sunlight Earth does—comparable to conditions on Mars—but its dense atmosphere could offer insulation against the cold. This planet orbits a cool red dwarf star and completes a full revolution in just 6.1 Earth days. Because the star is so faint, even this short orbit keeps the planet in a temperature range potentially friendly to life. One hidden truth about TRAPPIST-1e is its potential for tidal locking—meaning one side may permanently face the star while the other remains in darkness. However, with a thick enough atmosphere, heat could circulate globally, creating a “terminator line” climate suitable for life. What’s astonishing is that all seven planets in this system could fit inside the orbit of Mercury, making for spectacular sky views—planets would appear larger than the Moon does from Earth. TRAPPIST-1e’s proximity to Earth has made it a top target for the James Webb Space Telescope, which is now analyzing its atmosphere for biosignatures. Historically, this discovery shook the scientific world by proving that entire systems of Earth-sized planets could form around red dwarfs, once thought too unstable for life. If life exists in that system, it may even hop between planets through natural panspermia—a theory that life can be shared via meteorites and comets. TRAPPIST-1e is more than just a candidate; it’s a cosmic crossroads for the imagination.

#4: Proxima Centauri b (1.1x Earth Radius, 4.2 Light-Years Away)

Orbiting the closest star to our solar system, Proxima Centauri b is a tantalizing prospect for future exploration. Discovered in 2016, this exoplanet lies just 4.2 light-years away in the Alpha Centauri system. It orbits its red dwarf host every 11.2 days and resides within the habitable zone, where temperatures could allow liquid water under the right conditions. Though slightly larger than Earth and probably more massive, Proxima b remains one of the most Earth-like worlds by virtue of its proximity. What makes this planet particularly intriguing is how close it brings the dream of interstellar exploration; projects like Breakthrough Starshot aim to send tiny probes propelled by light sails to reach this system within decades. However, life on Proxima b wouldn’t be easy—its star is known for violent flares, which could strip away atmospheres and fry unprotected organisms. Yet, if Proxima b has a magnetic field or a thick enough atmosphere, it might mitigate these dangers. A lesser-known fact is that Proxima b could be part of a multi-planet system, with Proxima Centauri c and d possibly orbiting farther out, though their potential for life is less promising. Historically, this discovery reignited serious interest in interstellar missions for the first time since the Voyager probes. Though we can’t yet image Proxima b directly, its presence next door keeps it front and center in the search for alien life. What if the first sign of extraterrestrial biology comes from a signal just over four light-years away?

#5: LHS 1140 b (1.4x Earth Radius, 40 Light-Years Away)

LHS 1140 b is a rocky exoplanet orbiting a red dwarf star in the constellation Cetus, about 40 light-years from Earth. Discovered in 2017, this planet is about 40% larger than Earth and completes an orbit every 25 days. What makes it extraordinary is its dense composition—suggesting a massive iron core and potentially a very Earth-like geology. It sits within the conservative habitable zone of its star, making it one of the best candidates for habitability that we’ve found so far. One of the most interesting aspects of LHS 1140 b is that it likely retained its atmosphere, even while forming during the volatile early phases of its star’s life—a rare feat for planets orbiting red dwarfs. This is a significant advantage because it means the planet might still have a stable climate and surface water. The planet’s atmosphere is now under scrutiny by the James Webb Space Telescope, which could soon reveal traces of water vapor, oxygen, or even methane—potential indicators of life. What few people realize is that the star LHS 1140 is unusually quiet for a red dwarf, with minimal flare activity, which increases the chance for habitability over the long term. Scientists have even speculated that LHS 1140 b could host an ocean-covered surface or perhaps even continents. If Earth has a cousin in the neighborhood, this might be it.

#6: Gliese 667Cc (1.5x Earth Radius, 23.6 Light-Years Away)

Gliese 667Cc orbits a red dwarf star in a trinary star system in the constellation Scorpius. Located just 23.6 light-years from Earth, it lies in the habitable zone of its parent star and is about 50% larger in diameter than Earth. This exoplanet receives roughly 90% of the energy Earth gets from the Sun, which could allow for surface temperatures conducive to liquid water. It completes an orbit in just over 28 Earth days and may be tidally locked like many planets orbiting red dwarfs. The exciting twist here is that it’s part of a triple star system, meaning the sky could include stunning sunrises with multiple stars rising at once—a dreamlike landscape for future explorers or speculative fiction writers. Although Gliese 667Cc’s composition isn’t fully confirmed, it’s strongly believed to be rocky, and models suggest it could maintain a stable climate zone between its day and night hemispheres. One of the underappreciated aspects of this planet is its role in shifting perceptions about red dwarfs. Before its discovery, many astronomers thought red dwarfs couldn’t host habitable worlds. Now, systems like Gliese 667 have shown otherwise. With a relatively close distance and favorable orbit, Gliese 667Cc remains a top candidate for future telescopic imaging and atmospheric scanning.

#7: TOI 700 d (1.1x Earth Radius, 101.4 Light-Years Away)

TOI 700 d was discovered in 2020 by NASA’s Transiting Exoplanet Survey Satellite (TESS), marking a major milestone for the mission as its first Earth-sized planet in the habitable zone. Located about 101.4 light-years away in the Dorado constellation, TOI 700 d is just 10% larger than Earth and orbits a quiet M-dwarf star every 37 days. It receives roughly 86% of the energy that Earth receives from the Sun, placing it comfortably in the habitable zone where surface water could theoretically exist. What makes this planet stand out is not just its similarity in size and insolation to Earth, but the stability of its host star—unlike many red dwarfs, TOI 700 is remarkably calm, with minimal flare activity. This dramatically improves the chances that TOI 700 d retains a protective atmosphere over long geological timescales. In terms of hidden gems, few people know that this planet’s discovery was independently confirmed not just by astronomers, but also with the help of citizen scientists working with the Planet Hunters project. It’s one of the rare cases where amateur volunteers played a role in verifying an Earth-like world. TOI 700 d is part of a system with at least three other known planets, and its stable orbit allows astronomers to plan long-term atmospheric studies. While we’ve yet to confirm the exact composition of its atmosphere, simulations suggest it could support Earth-like climates under the right conditions. This planet has already inspired speculative climate models simulating oceans, cloud coverage, and even photosynthesis using red sunlight. In a way, TOI 700 d is one of the most democratic planets ever discovered—made known to us through the collaboration of professional scientists and ordinary stargazers alike.

#8: Kepler-62f (1.4x Earth Radius, 1,200 Light-Years Away)

Located in the constellation Lyra about 1,200 light-years from Earth, Kepler-62f is part of a five-planet system and is especially notable for being both Earth-sized and within its star’s habitable zone. With a radius about 40% greater than Earth’s and an orbital period of 267 days, this exoplanet was discovered in 2013 and has been a subject of intense study ever since. Kepler-62f orbits a K-type star—smaller and cooler than our Sun—but still capable of supporting a habitable environment for the right kind of planet. Kepler-62f receives about 41% of the sunlight Earth does, which might sound cold, but if the planet has a thick atmosphere rich in carbon dioxide or other greenhouse gases, it could easily maintain liquid water on its surface. What’s intriguing here is that Kepler-62f has become a popular candidate in climate modeling studies. Scientists have explored dozens of scenarios involving cloud coverage, orbital eccentricity, and atmospheric compositions, and many of them suggest the planet could host life-friendly temperatures. Historically, Kepler-62f was one of the earliest planets found in the habitable zone that wasn’t a gas giant or mini-Neptune, boosting confidence that rocky Earth-like worlds were common in our galaxy. Although it’s too far for direct imaging with current technology, Kepler-62f remains a scientific favorite because it shows just how varied life-supporting conditions might be. A lesser-known aspect is that Kepler-62f is often used in science outreach and classroom simulations because it combines a vivid data story with real potential for life. It has even inspired virtual reality environments and speculative art.

#9: Ross 128 b (1.1x Earth Radius, 11 Light-Years Away)

Ross 128 b is one of the quiet success stories of exoplanet hunting. Discovered in 2017, it orbits a red dwarf star just 11 light-years away in the constellation Virgo. This planet is slightly more massive than Earth and orbits its host star every 9.9 days. Despite the tight orbit, Ross 128 b receives only about 38% more stellar radiation than Earth does, thanks to the cool temperature of its parent star. The proximity of this system makes Ross 128 b one of the most attractive targets for future observation, especially with the next generation of ground-based telescopes. One of the most fascinating elements here is the quiescent nature of its host star—Ross 128 is one of the calmest red dwarfs known, emitting few flares and maintaining long-term stability. This gives Ross 128 b a better chance of preserving an atmosphere, a rarity for planets around red dwarfs. Hidden behind this technical data is an interesting cultural twist: when Ross 128 b was discovered, it was briefly suspected of being associated with a mysterious radio signal picked up by the Arecibo Observatory. Though later traced to Earth-based interference, the media frenzy underscored how eager we are for signs of life. Ross 128 b has also entered discussions about future interstellar missions due to its relatively close proximity. While we don’t yet know what the surface looks like, it’s conceivable that an atmosphere rich in nitrogen or carbon dioxide could support temperate conditions.

#10: K2-18b (2.7x Earth Radius, 124 Light-Years Away)

K2-18b may not be a perfect Earth twin—it’s about 2.7 times the radius of Earth and likely more of a mini-Neptune than a rocky world—but its atmospheric potential secures it a place on this list. Located 124 light-years away in the Leo constellation, K2-18b orbits a red dwarf star every 33 days. In 2019, it became the first exoplanet in the habitable zone where water vapor was detected in its atmosphere—a landmark discovery. While its larger size suggests a thick hydrogen-rich envelope more akin to a gas dwarf, this doesn’t rule out the possibility of a rocky or ocean-covered core beneath that blanket. One thing few people realize is how much debate K2-18b stirred in the scientific community. Its atmospheric makeup prompted renewed discussion about what we really mean by “Earth-like.” Some argued it shouldn’t qualify, while others insisted that if it has water, temperatures, and an energy source, it’s fair game for habitability. In 2023, further observations revealed signs of dimethyl sulfide—on Earth, a compound only known to be produced by life, particularly plankton. Though far from conclusive, it reignited hopes that alien biospheres might not be limited to rocky planets alone. K2-18b is a reminder that life may thrive in forms and environments very different from our own, possibly in high-pressure oceans beneath hydrogen skies.

Reflections from the Final Frontier

The discovery of Earth-like exoplanets marks one of the most profound shifts in human understanding of our place in the universe. Each planet in this list has challenged and expanded our definition of what it means to be “like Earth.” From the volcanic mystery of Kepler-452b to the ocean-bearing potential of K2-18b, these worlds ignite scientific curiosity and human imagination alike. They remind us that Earth may not be an anomaly, but one voice in a cosmic choir of habitable worlds. While none of these exoplanets has yet yielded definitive signs of life, each serves as a beacon guiding our technological advancements, exploration dreams, and philosophical reflections. With new observatories like the James Webb Space Telescope and future missions such as LUVOIR and HabEx, we stand on the edge of a new age—one where the question is no longer if Earth-like planets exist, but when we’ll find the one that finally answers back.