from the Ross-128?-When-did-Harry-Mudd-join-"Friends"? dept.
Astronomers using the High Accuracy Radial velocity Planet Searcher (HARPS) at the La Silla Observatory in Chile have discovered an Earth-sized exoplanet orbiting a red dwarf in its "habitable zone". The star, Ross 128, is about 10.89 light years away and is less active than Proxima Centauri, possibly boosting the chances of its exoplanet being habitable. Ross 128b has a minimum mass of about 1.35 Earth masses, and is considered by its discoverers to be "the best temperate [exo]planet known to date". The next step will be to determine the atmospheric composition of Ross 128b:
There's still uncertainty about whether Ross 128 b is within its star's habitable zone, but scientists say that with temperatures of between -60 and +20°C, it can be considered temperate.
Next, astronomers want to study the atmospheric composition and chemistry of suitable, nearby worlds like Ross 128 b. The detection of gases such as oxygen could potentially point to biological processes on planets orbiting other stars.
Several gases have already been detected in the atmospheres of exoplanets, but this line of enquiry is expected to be boosted immeasurably when observatories such as the European Southern Observatory's Extremely Large Telescope (E-ELT) and Nasa's James Webb Space Telescope (JWST) come online in the next few years.
Although currently 11 light-years from Earth, the new planet's parent star Ross 128 is moving towards us and is expected to overtake Proxima Centauri as our nearest stellar neighbour in just 79,000 years - a heartbeat on cosmic timescales.
A temperate exo-Earth around a quiet M dwarf at 3.4 parsecs (open, DOI: 10.1051/0004-6361/201731973) (DX)
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Alien Life Could Thrive On Four Earth-Like Planets Close To The Solar System, Says Study
Alien life could be evolving right now on some of the nearest exoplanets to our solar system, claim scientists at Cornell University in Ithaca, New York. Their proof is you.
It's been presumed that the high levels of radiation known to be bombarding many of the rocky Earth-like exoplanets discovered so far by astronomers precludes life, but that theory is turned on its head by new research published [open, DOI: 10.1093/mnras/stz724] [DX] in Monthly Notices of the Royal Astronomical Society.
In "Lessons from Early Earth: UV Surface Radiation Should Not Limit the Habitability of Active M Star System", the authors say that all of life on Earth today evolved from creatures that thrived during an era of much higher levels of UV radiation assault. So why not life on alien worlds? It also poses another question: does the evolution of life actually require high levels of radiation?
The exoplanets studied are Proxima b, TRAPPIST-1e, Ross 128 b, and LHS 1140 b.
Related: ESO Confirms Reports of Proxima Centauri Exoplanet
Proxima b May Have Oceans
Seven Earth-Sized Exoplanets, Including Three Potentially Habitable, Identified Around TRAPPIST-1
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An Earth-Like Atmosphere May Not Survive the Radiation in Proxima b's Orbit
Hubble Observations Suggest TRAPPIST-1 Exoplanets Could Have Water
Ross 128b: A Newly Discovered "Earth-Like" Exoplanet Orbiting a Less Active Red Dwarf
Another TRAPPIST-1 Habitability Study
(Score: 4, Funny) by takyon on Thursday November 16 2017, @10:05AM
https://en.wikipedia.org/wiki/List_of_nearest_stars [wikipedia.org]
https://en.wikipedia.org/wiki/File:Near-stars-past-future-en.svg [wikipedia.org]
Ross 128 will be the closest star in around 70,000 years, but it will be just under 7 light years away, whereas the Centauri system is about 4.24-4.36 light years away today (2.9-2.97 light years away at closest approach in ~28,000 years) and Ross 248 will be 3 light years away in 36,000 years. Gliese 445, Barnard's Star, and Lalande 21185 also come closer before then. Look forward to it.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 4, Interesting) by StupendousMan on Thursday November 16 2017, @01:21PM (2 children)
The authors of the paper use measurements of the host star's optical spectrum to infer that it doesn't produce a lot of UV emission, and note that it doesn't have frequent optical flares. That's good news for the habitability of the planet around it, as they point out.
However, they apparently did not note that Ross 128 is a relatively strong X-ray source, as measurements by the ROSAT X-ray satellite show. A colleague of mine worked out the X-ray luminosity of the host star, and it turns out to be not unlike that of the Sun, or even larger. That means that the X-ray flux striking the planet -- which is very close to this host star -- is likely high enough to remove the atmosphere of the planet. No atmosphere means not so interesting a planet, alas.
(Score: 3, Informative) by takyon on Thursday November 16 2017, @01:31PM (1 child)
https://www.nytimes.com/2017/11/15/science/planet-ross-128.html [nytimes.com]
This wrangling can be solved once new telescopes like the JWST and E-ELT are up and running.
If the planet has a higher surface gravity than Earth, perhaps it can retain a thick atmosphere despite powerful UV/x-ray emissions.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2) by bob_super on Thursday November 16 2017, @06:49PM
> That amount of radiation might be enough to destroy the planet’s atmosphere.
or just mean a different kind of atmosphere from what our narrow-minded models think possible.
Aliens are gray with black eyes because they photosynthesize and see in the X-ray range.
(Score: 1) by ian991 on Thursday November 23 2017, @05:59PM
Great discovery..
It is only 11 light years away! Will we ever make it to travel that long distance?
After Proxima, this is most Earth-like http://www.evolving-science.com/space/habitable-exoplanet-discovered-close-earth-00495 [evolving-science.com]exoplanet discovered