Top 5 Most Earth-Like Planets

By Andrew Dunbar, Co-Founder at Kickstart STEM

Ever look out into space and wonder if alien life may be out there in the distance? Well, since we know that our planet Earth is rich of organic matter, we can only imagine that the most earth-like planets may be the best candidates for otherworldly existence.

Based on Earth Similarity Index (ESI), scientists have found a metric to compare the relative earth-likeness of various planets in our viewable universe. So far, the top 5 earth-like planets within reasonable distances have been argued to be:

1. Kepler 438b: ESI = 0.88
2. Gliese 667Cc: ESI = 0.85
3. Kepler 442b: ESI = 0.84
4. Kepler 62f: ESI = 0.83
5. Kepler 452b: ESI = 0.83

Let’s explore what these planets are really like!

1. Kepler 438b: Earth Similarity Index = 0.88

The planet exists 470 light years away from Earth, and at only 10% larger than Earth and receiving roughly the same amount of solar energy from its star as the Earth does from the sun, individuals have argued for a long time that life may be viable on this planet. However, its sun is only about half the size of ours, and its on average 2,000 degrees cooler–a mostly red and infrared radiating star. Though human life may not be viable on this planet for these reasons, experts argue that general life may in fact be in some other form.

2. Gliese 667 Cc: Earth Similarity Index = 0.85

Gliese 667Cc orbits within the “habitable” zone of a red dwarf star approximately 22.18 light years away from Earth. The exoplanet (a planet which orbits a star) has a mass approximately 3.7x that of Earth’s, and has an equilibrium temperature of 39.6 degrees Fahrenheit (compared to -1 degrees Fahrenheit for Earth). According to Nasa studies, based on black body radiation the planet should absorb only slightly more electromagnetic radiation as Earth, explaining the slightly higher equilibrium temperature. Moreover, the sun that this planet orbits is a red dwarf star with about a third of the mass of the sun and a life expectancy 10-15 times longer than our sun.

3. Kepler 442b: Earth Science Index = 0.84

Kepler 442b is considered a “super Earth” planet. Orbiting its star 1,206 light years from Earth in the constellation Lyra, the planet has an orbital period of 112.3 days and a mass approximately 2.3 that of Earth’s. In fact, its star is approximately 40% less massive than the Sun, so it can live for about 30 billion years compared to our Sun’s 5 billion years. Fun fact: this planet was discovered by the “transit method” in which the planet’s “dimming effect” caused by crossing in front of its star is measured. Oh, and also, gravity on Kepler 442b is 30% stronger than Earth’s, so if you weigh 100 pounds on Earth, you’ll instantly be 130 pounds on Kepler!

4. Kepler 62f: Earth Similarity Index = 0.83

This super Earth planet is located about 990 light years away from Earth in constellation Lyra. Kepler 62f orbits its star at roughly 66,000,000 miles from its host star, with an orbital period of roughly 267.3 days. Its mass is 2.8 times that of Earth’s, and has a radius of approximately 1.41 times that of Earth (think square root of two!) Its parent star is relatively quiet, and has less mass than our Sun so it can live significantly longer. According to experts, its atmospheric viability is not currently known, but its physical properties so far discovered have been deemed quite promising for potential habitability.

5. Kepler 452b: Earth Similarity Index = 0.83

Called the “bigger, older cousin to Earth,” Kepler 452b exists in the habitable zone around a G2 type star–the same type of star as our very own sun. Liquid water is known to pool on the surface of this planet, likely because of its proximity to the star, and the planet has roughly 60% larger diameter than Earth. While its mass and composition aren’t yet determined, Nasa says this planet is rocky, and can offer insight into the potential future of Earth. Kepler 452b is 1400 light years away in the constellation Cygnus, so speedy travel will be necessary to ever get there. Are there aliens already on this planet? Maybe!!

Thanks for enjoying our blog about the top 5 earth like planets. For more cool info, subscribe to our newsletter and get weekly updates about new cool articles!