We Just Discovered One of the Closest Earth-Like Planets Ever

We Just Discovered One of the Closest Earth-Like Planets Ever

We Just Discovered One of the Closest Earth-Like Planets Ever

A temperate Earth-sized planet has been discovered only 11 light-years from the Solar System by a team using ESO's unique planet-hunting HARPS instrument.

An artist's impression of exoplanet Ross 128 b, with its red-dwarf parent star in the background.

Astronomers spotted the planet using the European Southern Observatory's High Accuracy Radial velocity Planet Searcher (HARPS) in Chile. There are many exoplanets orbiting dwarf stars with the potential to support life, but most of those stars are very active and throw off enough radiation to destroy anything living.

The newly discovered exoplanet orbits its star 20 times closer than Earth orbits the sun.

Digitized Sky Survey 2 Acknowledgement: Davide De Martin This image shows the sky around the red dwarf star Ross 128 in the constellation of Virgo (The Virgin). Ross 128 is the "quietest" nearby star to host such a temperate exoplanet.

The only closer temperate planet is Proxima b, whose star, another red dwarf, bombards it with ultraviolet and X-ray radiation, possibly rendering it uninhabitable.

Two things to keep in mind: We don't know yet if Ross 128b has an atmosphere or, if it has one, whether that atmosphere has the proper composition to support life as we know it.


All of that, combined with the fact that Ross 128 is such an inactive star, makes this planet a prime candidate in the search for extraterrestrial life.

With the data from HARPS, the team found that Ross 128 b orbits 20 times closer than the Earth orbits the Sun. And it is just 11 light-years from our solar system, making it the second-closest temperate planet to ever be detected. Ross 128 b's location - either inside, outside or on the edge of the habitable zone - could determine whether the planet's surface could contain liquid water.

Bonfils said Ross 128 appears to be at least 5 billion years old - older than our solar system - and perhaps as old as 10 billion years.

As of now, scientists aren't sure whether the alien world is in or out of the habitable zone - the orbital range in which exoplanets can host water in liquid form.

First, the star it orbits is relatively quiet. "Some models made by theorists say that a wet Earth-size planet with such irradiation would form high-altitude clouds". As astronomers paid more attention, they began realizing that Proxima Centauri, like many red dwarfs, was probably incredibly active in its youth, spewing intense amounts of stellar radiation that would have nearly certainly bludgeoned the small planet. Such flares may well sterilize any life that might develop on such a world. "If we are able to identify all three [gases] in the same exoplanet atmosphere, it would be a smoking gun for life on the surface", says Bonfils. "It is common that stars harbor more than a single planet", Astudillo-Defru told Futurism.

More exoplanets are being discovered by astronomers due in part to tools like HARP and ESO's Extremely Large Telescope.

Astronomers estimate that in 79,000 years, Ross 128 b will be our exoplanet neighbor, even closer than Proxima b.

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