Connect with us

Hi, what are you looking for?


Life can evolve on small planets with 3% of Earth’s mass.

Life can evolve on small planets with 3% of Earth’s mass. 1

Could a tiny planet with weak gravity harbor life?

A team of scientists from Harvard University say they’ve found the smallest possible mass a planet could be before its lack of gravitational forces would cause it to lose its atmosphere and any liquid water.

They found that the smallest possible planet that could maintain those life-enabling properties would be about 2.7 percent of the mass of Earth. That’s a little more than twice the mass of the Moon and roughly half the mass of Mercury.

An exoplanet is said to be in a star’s habitable zone if it’s at the right distance to be able to support liquid water. If it’s too close, it would receive too much radiation from its sun, making it too hot. Too far, and it’d be too cold for liquid water.

Astronomer Constantin Arnscheidt, lead author of the article describing the research, published in Astrophysical Journal in August told the Astrobiology Magazine:

When people think of the inner and outer edges of the habitable zone, they tend to think only spatially, meaning how close the planet is to the star. But in fact, there are many other habitability variables, including the mass (of a planet).

If exoplanets are big enough, the researchers found there’s enough of a greenhouse effect to keep them at the right temperature, regardless of their positions inside the habitable zone. That’s because the atmosphere of these relatively small planets would expand outwards thanks to relatively low gravity, which in turn would cause it to absorb more radiation from its star and thereby stabilize temperatures on its surface.

Interestingly, the research would rule out tiny ice worlds in Jupiter’s orbit — they’d be too small. These icy moons have had scientists excited about the possibility of life thanks to massive underground oceans.

But the research suggests that there could be plenty of other places we haven’t discovered yet that are just the right size.


Advertisement. Scroll to continue reading.

You May Also Like


Astronomers have discovered a system of six exoplanets orbiting a star with a specific orbital resonance. The star system known as TOI-178 is located...


The new platform Planet Patrol allows civil volunteers cooperate with professional astronomers in the sorting process the huge number of shots , the collected satellite Transiting...


Almost every star you see in the night sky serves as the center of the planetary system, and there are about 100 billion stars...


Until recently, in search of inhabited exoplanets, binary star systems were completely undeservedly ignored. Exoplanets with two suns have long become familiar places where...


Scientists have discovered a new way to find oxygen on distant planets, and this could help them discover alien life. Conceptual image of exoplanet...


The scientists of National Institute of Standards and Technology – NIST recently created one of the highest performing cameras ever made up of sensors...


“CHEOPS will take exoplanet science to a whole new level,” Günther Hasinger, ESA Science Director has said, on the newest orbital telescope in the...