Illustration of an Earth-like planet. Image: Lev Savitskiy/Shutterstock
It seems as if a new ‘Earth 2.0’ is discovered every month, and this particular planet is being described as the best candidate to potentially host alien life.
As our technology to analyse distant planets in greater detail improves by the decade, the number of Earth-like discoveries is also increasing dramatically.
In February of this year, NASA announced the single biggest haul of Earth-like planets, revealing seven in total – six that could sustain liquid water – orbiting a star called TRAPPIST-1.
The European Southern Observatory (ESO) has now revealed the latest contender for ‘Earth 2.0’, located in the constellation of Cetus – otherwise known as the ‘Sea Monster’ – approximately 40 light years from Earth.
Readings from the planet called LHS 1140b show that it is approximately 5bn years old with a diameter 1.4 times that of Earth, or 18,000km.
Not only that, but its mass is seven times greater than Earth’s, suggesting a planet made of rock with a dense iron core.
Another good sign for astronomers that this planet could sustain life is that, despite its orbit around its parent star being 10 times closer than our own, the red dwarf star only emits half the amount of light as the sun.
While red dwarf stars are known for emitting enough radiation to damage many planets’ atmospheres during their earliest formation, LHS 1140b’s size means that a magma ocean could have existed on its surface for millions of years.
This means that the steam generated from the lava on the surface could be emitted into the atmosphere until the star has calmed down, replenishing the planet with water.
Artist’s impression of exoplanet LHS 1140b. Image: ESO/spaceengine.org
‘Most exciting exoplanet I’ve seen in the past decade’
Publishing their findings in the journal Nature, researchers from the Geneva Observatory in Switzerland made the discovery after its MEarth facility detected the characteristic dips in light as the exoplanet passed in front of the star.
“This is the most exciting exoplanet I’ve seen in the past decade,” said lead author Jason Dittmann of the Harvard-Smithsonian Center for Astrophysics.
“We could hardly hope for a better target to perform one of the biggest quests in science – searching for evidence of life beyond Earth.”
Further analysis of the planet will now be undertaken using the Hubble Space Telescope to assess exactly how much high-energy radiation is showered upon LHS 1140b.
When the ESO’s Extremely Large Telescope is operational, its atmosphere will be analysed in even greater detail.
