Exoplanets

From science writer Miriam Kramer at Mashable: Yes, it’s amazing that this possibly rocky planet is orbiting a star just 4 light-years away, possibly close enough to one day launch a mission to, but there is still so much we don’t know about this brave new world. Plus, Proxima b is far from being a twin of our planet. Scientists aren’t sure what kind of atmosphere it has or even if it’s able to support a magnetic field, two things that it would need to sustain habitability in orbit around its active, flaring star. We simply don’t know if it can support water, life or much of anything on its surface at all. Beyond the inaccuracy in this particular case, Read More ›

From Jacob Aron at New Scientist, A planet just 30 per cent more massive than Earth orbits in the habitable zone of Proxima Centauri, which is just 4.25 light years away. How Earth-like is it really? … The planet – Proxima b – was discovered by astronomers who spent years looking for signs of the tiny gravitational tug exerted by a planet on its star, after spotting hints of such disruption in 2013. Proxima Centauri is 4.25 light years from Earth, making it slightly closer than the binary star system of Alpha Centauri, which the Proxima star is thought to loosely orbit. More. From Rob Sheldon I wouldn’t get my hopes up. Years ago, people didn’t put this type of Read More ›

Don’t bet the farm but, from a href=”http://phys.org/news/2016-08-scientists-unveil-earth-like-planet.html” target=”another”>Phys.org: The exoplanet orbits a well-investigated star called Proxima Centauri, part of the Alpha Centauri star system, the magazine said, quoting anonymous sources. “The still nameless planet is believed to be Earth-like and orbits at a distance to Proxima Centauri that could allow it to have liquid water on its surface—an important requirement for the emergence of life,” said the magazine. “Never before have scientists discovered a second Earth that is so close by,” it said, adding that the European Southern Observatory (ESO) will announce the finding at the end of August. More. See also: “Behold, countless Earths sail the galaxies … that is, if you would only believe …” Follow UD Read More ›

Asks Adam Frank: Earlier this year, my colleague Woody Sullivan and I published a paper in the journal Astrobiology presenting new results that, I believe, throw new light on the ancient question. And, based on that work, last month I wrote an OpEd in The New York Times that ran with provocative title “Yes, There Were Aliens.” The Times piece found a large audience and generated strong responses running from agreement to dissent to folks telling me I really should look into UFOs (sorry, not my thing). Just what he’s got against the UFOs is not, under the circumstances, clear. But anyway, One of the principle objections raised to my piece was that the fact that just because 10-22 is Read More ›

From Sarah Knapton at Telegraph: In January, astronomers Professor Konstantin Batygin and Professor Mike Brown from California Institute of Technology predicted the existence of a ninth planet after discovering that 13 objects in the Kuiper Belt – an area beyond Neptune – were all moving together as if ‘lassooed’ by the gravity of a huge object. Now scientists from Cambridge University and Spain have discovered that the paths of the dwarf planets are not as stable as they thought, meaning they could be falling under the influence of more planets further out.More. See also: Planet better than Earth claimed within reach Follow UD News at Twitter!

From MacGregor Campbell at at New Scientist: We are used to thinking small when it comes to alien life. Our list of living worlds has a sole data point, Earth, and even our convivial planet seems to have been a tricky place for life to get started. How could we expect more than a self-replicating bag of biomolecules anywhere else? That might be too lofty a view of Earth. After all, huge areas of our planet, including the poles and deserts, are rather barren. And whole epochs of time were inhospitable to life. More. So, of course, “There should be worlds out there so balmy they make Earth look stale, and there are signs of one just four light years Read More ›

From BBC News: It has also detected nine small planets within so-called habitable zones, where conditions are favourable for liquid water – and potentially life. The finds are contained within a catalogue of 1,284 new planets detected by Kepler – which more than doubles the previous tally. … The Nasa Ames researcher said the Kepler mission was part of a “larger strategic goal of finding evidence of life beyond Earth: knowing whether we’re alone or not, to know… how life manifests itself in the galaxy and what is the diversity”. She added: “Being able to look up to a point of light and being able to say: ‘That star has a living world orbiting it.’ I think that’s very profound Read More ›

From Discover: Earth May Be a 1-in-700-Quintillion Kind of Place One of the most fundamental requirements for a planet to sustain life is to orbit in the “habitable zone” of a star — the “Goldilocks” region where the temperature is just right and liquid water can exist. Astronomers have, to this point, discovered around 30 exoplanets in the habitable zones of stars. Simply extrapolating that figure based on the known number of stars suggests that there should be about 50 billion such planets in the Milky Way alone. Probability seems to dictate that Earth-twins are out there somewhere. But according to Zackrisson, most planets in the universe shouldn’t look like Earth. His model indicates that Earth’s existence presents a mild Read More ›

From Scientific American: More than 400 years ago Renaissance scientist Nicolaus Copernicus reduced us to near nothingness by showing that our planet is not the center of the solar system. With every subsequent scientific revolution, most other privileged positions in the universe humans might have held dear have been further degraded, revealing the cold truth that our species is the smallest of specks on a speck of a planet, cosmologically speaking. A new calculation of exoplanets suggests that Earth is just one out of a likely 700 million trillion terrestrial planets in the entire observable universe. But the average age of these planets—well above Earth’s age—and their typical locations—in galaxies vastly unlike the Milky Way—just might turn the Copernican principle Read More ›

It’s the latest new prejudice. From Quanta, we earn that the presence of oxygen does not show, as formerly thought, that a planet might have life. Oxygen can build up in environments hostile to life: As Domagal-Goldman, then a researcher at the University of Washington’s Virtual Planetary Laboratory (VPL), well knew, the gold standard in biosignature gases is oxygen. Not only is oxygen produced in abundance by Earth’s flora — and thus, possibly, other planets’ — but 50 years of conventional wisdom held that it could not be produced at detectable levels by geology or photochemistry alone, making it a forgery-proof signature of life. Oxygen filled the sky on Domagal-Goldman’s simulated world, however, not as a result of biological activity Read More ›

So reports Ethan Siegel at Forbes: Yesterday, results were released from an international team led by Alexandre Santerne from Instituto de Astrofísica e Ciências do Espaço, where they measured 129 objects-of-interest identified by Kepler for a period of five years. They did spectroscopic analysis, which means they studied the individual wavelengths of light coming from the star, and expected a false positive rate of about 10-to-20%, which is what most scientists estimated. But they found, instead, that over half (52%) of the planetary candidates were, in fact, eclipsing binaries, with another three candidates turning out to be brown dwarfs. … But perhaps the biggest surprise is that the majority of these thought-to-be planets aren’t planets at all, but are massive Read More ›

From New Scientist: Recent theory: The idea is that smaller, colder stars have thicker atmospheres. “That provides handles with which the star can grab onto the planet and vice versa,” Winn says. Over time, those gravitational handles exert a tidal force on the planet, pulling it and its star into alignment. But then: But one Jupiter-mass planet discovered earlier this year, HATS-14b, seems to threaten that idea. Because it tightly circles a small star, its orbit should have flattened out quickly – but the orbit is instead tilted a whopping 76 degrees from the plane in which its star spins. “It should have aligned with the spin of the host star, and what we’re finding is that it has not,” Read More ›

From Nature: What we know about alien worlds — and what’s coming next. The tally of known extrasolar planets now stands at 1,978, with nearly 4,700 more candidates waiting to be confirmed. On 29 November, exoplanet researchers will gather in Hawaii to review these extreme solar systems — and map out a path for the next two decades. Free infographic here. Here’s an interesting new find from May 2014: Goldilocks may not like exoplanets. Maybe that’s because of stuff like this? Radiation nixes most Earth-like planet for life? Researchers: Atmosphere of Kepler-438b would be stripped away. See also: Don’t let Mars fool you. Those exoplanets teem with life! Follow UD News at Twitter!

From Warwick U: The most Earth-like planet could have been made uninhabitable by vast quantities of radiation, new research led by the University of Warwick has found. The atmosphere of the planet, Kepler-438b, is thought to have been stripped away as a result of radiation emitted from a superflaring Red Dwarf star, Kepler-438. Regularly occurring every few hundred days, the superflares are approximately ten times more powerful than those ever recorded on the Sun and equivalent to the same energy as 100 billion megatons of TNT.More. The find raises a question about how we determine whether a planet is Earth-like. Most Earth-like planet uninhabitable due to radiation, new research suggests C/NET laments, Farewell to hope of life on Kepler-438b, adding Read More ›

From Smithsonian: Ancient volcanic rocks may have preserved tiny samples of the planet’s original moisture A new analysis in Science suggests that at least some of Earth’s current moisture derives from water-soaked dust particles trapped deep inside during the planet’s formation. … The ratio of deuterium to hydrogen in the universe was fixed shortly after the Big Bang. But various processes can alter that ratio in certain locations. On Earth, hydrogen can be stripped out of the atmosphere by the solar wind, and deuterium can be added through cometary impacts. More. In the most ancient rocks, researchers found some of the lowest ratios of deuterium to hydrogen ever recorded, suggesting that water was there from the beginning. From New Scientist: Read More ›