There are at least 300 million potentially habitable planets in our galaxy, NASA finds

By Jessie Yeung, CNN

Updated 0457 GMT (1257 HKT) November 6, 2020

Astronomers have identified a new class of habitable planets, which they call Hycean planets. These are hot, ocean-covered planets with hydrogen-rich atmospheres.
Photos: Weird and wonderful planets beyond our solar system
Astronomers have identified a new class of habitable planets, which they call Hycean planets. These are hot, ocean-covered planets with hydrogen-rich atmospheres.
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This artist's illustration shows L 98-59b, one of the planets in a planetary system 35 light-years away from Earth. This planet has half the mass of Venus.
Photos: Weird and wonderful planets beyond our solar system
This artist's illustration shows L 98-59b, one of the planets in a planetary system 35 light-years away from Earth. This planet has half the mass of Venus.
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In this artist's illustration, two gaseous exoplanets can be seen orbiting the bright sun-like star HD 152843.
Photos: Weird and wonderful planets beyond our solar system
In this artist's illustration, two gaseous exoplanets can be seen orbiting the bright sun-like star HD 152843.
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An artist's rendering of TOI-1231 b, a Neptune-like planet about 90 light years away from Earth.
Photos: Weird and wonderful planets beyond our solar system
An artist's rendering of TOI-1231 b, a Neptune-like planet about 90 light years away from Earth.
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This artist's conception depicts a violent flare erupting on the star Proxima Centauri as seen from the viewpoint of a planet orbiting the star called Proxima Centauri b.
Photos: Weird and wonderful planets beyond our solar system
This artist's conception depicts a violent flare erupting on the star Proxima Centauri as seen from the viewpoint of a planet orbiting the star called Proxima Centauri b.
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This artist's illustration shows the night-side view of the exoplanet WASP-76b, where iron rains down from the sky.
Photos: Weird and wonderful planets beyond our solar system
This artist's illustration shows the night-side view of the exoplanet WASP-76b, where iron rains down from the sky.
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After losing its gaseous envelope, the Earth-size core of an exoplanet formed a second atmosphere. It's a toxic blend of hydrogen, methane, and hydrogen cyanide that is likely fueled by volcanic activity occurring beneath a thin crust, leading to its cracked appearance.
Photos: Weird and wonderful planets beyond our solar system
After losing its gaseous envelope, the Earth-size core of an exoplanet formed a second atmosphere. It's a toxic blend of hydrogen, methane, and hydrogen cyanide that is likely fueled by volcanic activity occurring beneath a thin crust, leading to its cracked appearance.
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This illustration shows the metaphorical measuring of the density of each of the seven planets in the nearby TRAPPIST-1 system. New measurements have revealed the most precise densities yet for these planets and they're very similar -- which means they also likely have similar compositions.
Photos: Weird and wonderful planets beyond our solar system
This illustration shows the metaphorical measuring of the density of each of the seven planets in the nearby TRAPPIST-1 system. New measurements have revealed the most precise densities yet for these planets and they're very similar -- which means they also likely have similar compositions.
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This artist's illustration shows the view from the furthest planet in the TOI-178 system.
Photos: Weird and wonderful planets beyond our solar system
This artist's illustration shows the view from the furthest planet in the TOI-178 system.
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This artist's illustration shows TOI-561b, one of the oldest and most metal-poor planetary systems discovered yet in the Milky Way galaxy. Astronomers found a super-Earth and two other planets orbiting the star.
Photos: Weird and wonderful planets beyond our solar system
This artist's illustration shows TOI-561b, one of the oldest and most metal-poor planetary systems discovered yet in the Milky Way galaxy. Astronomers found a super-Earth and two other planets orbiting the star.
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This massive and distant exoplanet, called HD106906 b, has an elongated and angled orbit that causes it to take 15,000 Earth years to complete one lap around its twin stars.
Photos: Weird and wonderful planets beyond our solar system
This massive and distant exoplanet, called HD106906 b, has an elongated and angled orbit that causes it to take 15,000 Earth years to complete one lap around its twin stars.
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