Planet that resembles Earth found 40 lightyears away


Artist's impression. Credit ESO

News was made in February when astronomers found seven potential earth-like planets orbiting the red dwarf star Trappist-1.

The planet lies 39 light years away and is believed to lurk in the habitable zone - where liquid water could support life as we know it - around a star named LHS 1140 in the constellation of Cetus, the sea monster.

Super-Earth is a rocky, temperate planet orbiting a red dwarf star, Efe news agency reported.

Astronomers estimate the planet to be at least five billion years old - about the same age as the Earth and long enough for life to have evolved.

The fact that LHS 1140b is a super-Earth is a bit concerning to any hopes that - if humans ever manage to master interstellar travel - we could one day settle the planet and establish a colony.

The discovery is quite unique because LHS 1140 is a small cool star, not as active energetically as other stars which other exoplanets have been found to orbit.

When red dwarf stars are young, they are known to emit radiation that can be damaging for the atmospheres of the planets that orbit them.

"It's very interesting to me that we have just discovered a super-Earth right up against that boundary", Dittman said.

Located just 40 light-years away, the planet was found using the transit method, in which a star dims as a planet crosses in front of it as seen from Earth.

Xavier Bonfils, an astronomer at the Observatory of the Sciences of the Universe in Grenoble, France, said LHS 1140b now "joins Trappist-1 at the head of the rankings".

Follow-up observations carried out by a range of telescopes, including the European Southern Observatory's HARPS instrument then went on to characterize the planet's mass, density, and orbital period.

The star that LHS 1140b orbits is both small and faint.

LHS 1140b is 10 times closer to its respective star than Earth is to the Sun, but only receives about half the sunlight.

Whether there is actually water on the planet or not depends on the composition of its atmosphere and other factors, including the presence of a magnetic field, such as the one Earth has, but the most important thing is for the planet to "fulfil the requirements to have water", which means that it must be in its star's habitable zone, Murgas said.

"Given its large surface gravity and cool insolation, the planet may have retained its atmosphere despite the greater luminosity (compared to the present-day) of its host star in its youth", the study authors wrote.

An artist rendering of the James Webb Space Telescope that NASA plans to launch in 2018. Three of the planets are in the Goldilocks zone, though all of the TRAPPIST-1 planets are believed to be rocky.

Exoplanet discoveries in the past decade have made it clear there are plenty of other solar systems, but in the a year ago we've increasingly spotted new worlds that indicate there may be plenty of other Earths out there too. These star types have become popular targets for exoplanet hunters, since they're also common throughout the galaxy and it's easier to spot planets around them. This affects the planet's ability to maintain an atmosphere, water and stable compounds.

But given the size and location of LHS 1140b, the planet is an obvious candidate for further research.

"Right now we don't have measurements of LHS 1140b's atmosphere or the atmosphere on other M dwarf rocky planets, and so a lot of this work is based upon theory and calculations", says Dittmann.

Since the star it orbits is quite small and relatively close to us, it may be possible for current telescopes and those now under construction to determine if the planet has an atmosphere.

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