Space

Closest exoplanet more Earth-like than previously thought

Closest exoplanet more Earth-l...
Artist’s impression showing a view of the surface of the planet Proxima b orbiting the red dwarf star Proxima Centauri, the closest star to the solar system
Artist’s impression showing a view of the surface of the planet Proxima b orbiting the red dwarf star Proxima Centauri, the closest star to the solar system
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Artist’s impression showing a view of the surface of the planet Proxima b orbiting the red dwarf star Proxima Centauri, the closest star to the solar system
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Artist’s impression showing a view of the surface of the planet Proxima b orbiting the red dwarf star Proxima Centauri, the closest star to the solar system

A team of international researchers has confirmed the existence of an Earth-like exoplanet only 4.2 light-years from the Sun. Using the Echelle SPectrograph for Rocky Exoplanets and Stable Spectroscopic Observations (ESPRESSO), the scientists found that the exoplanet Proxima b has a mass of 1.17 Earth masses and sits in the habitable zone of Proxima Centauri, which it orbits every 11.2 days.

First suspected to exist in 2013 and confirmed in 2016 by the European Southern Observatory's (ESO's) High Accuracy Radial Velocity Planet Searcher (HARPS) spectrograph, Proxima b is not only the closest exoplanet to us, but also looks more Earth-like as more accurate measurements come in.

According to the research team, led by Alejandro Suarez Mascareño of the Instituto de Astrofísica de Canarias (IAC), the new measurements of Proxima b came from the Swiss-manufactured ESPRESSO, which is a more advanced version of HARPS that is three times more accurate. By measuring the changes in the radial velocity of Proxima Centauri with an accuracy of 30 cm/s, the instrument showed that the mass of the exoplanet is 1.17 times that of the Earth, rather than the previous estimate of 1.3 Earths.

The question remains as to whether Proxima b is habitable. While it is 20 times closer to Proxima Centauri than the Earth is to the Sun, Proxima Centauri is a red dwarf star, so Proxima b is in the orbital zone where liquid water and, perhaps, life could exist. However, Proxima b receives 400 times more X-rays than the Earth, so other factors need to be investigated.

"Is there an atmosphere that protects the planet from these deadly rays?" says Christophe Lovis, a researcher in UNIGE’s Astronomy Department. "And if this atmosphere exists, does it contain the chemical elements that promote the development of life – oxygen, for example? How long have these favorable conditions existed? We’re going to tackle all these questions, especially with the help of future instruments like the RISTRETTO spectrometer, which we’re going to build specially to detect the light emitted by Proxima b, and HIRES, which will be installed on the future ELT 39 m giant telescope that the European Southern Observatory is building in Chile."

The research was published in Astronomy & Astrophysics.

Source: University of Geneva

5 comments
Zerozen
In regards of being habitable, seeing is to believing. we need faster probe propulsion and promoting starshot program.
Charles Gibilterra
Very interesting coverage, certainly continuse adding to our understanding of exoplanets. Question is other than knowledge gained, is there an end game in all of it; like should Proxima b orbiting the red dwarf star Proxima Centauri prove to be habitable, most likely already have existent life forms, what would be the possibility we'd attempt to colonize this planet 1.17 the size of Earth? Given we'er taking Earth down, would it be a questionable game plan to save us down the road? Or wouldn't it be better, easier, for us to save our own planet? We're dreamers, possibly dreaming the wrong dream? We remain locked into the Time Dimension, whereby the distances are so dimensionally beyond us, reaching these far off planets does not allow such dreams... Science, no matter how grandly expanding awareness cannot change the Time Wall~~~

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Douglas Bennett Rogers
This planet is reachable in 40 years using the Orion Project. This used all known physics but was much too expensive at the time. It might be easily buildable after asteroid mining is achieved.
Charles Gibilterra
Tuned into all taking place in science, for sure a WOW time we're living. Science constantly delivers all this amazing information here and looking out into the star fields whirling around in billions of galaxies spanning light year in their circumferences; a scale incomprehensible in their grandness.
Whether one believe in God or not, this vast warped infinity, beyond the beyond, remains the invisible wall retreating away from our spec in space, boggles all attempt at true understand, no matter the geniuses attempting to cross that threshold of invisibility, all remains the eternal mystery~~~ God may be in the details, but remains untouchable.
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Eddy
Whilst interesting and increasing our knowledge of the universe I don't think it's worth spending any more money on as it's too far away to ever be reached by humans, only costly probes which at that distance and greater will return only useless knowledge which will not improve our lot here.