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Scientists have found a "super-Earth" right next door – Salon

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Thirty years ago, no one knew if there were planets outside of our solar system. As astronomers figure out increasingly clever ways to observe even the tiniest (meaning Earth-size) planets in neighboring star systems, we now know that our galaxy is lousy with planets. Yet how many of them are like Earth — and how common Earth-like worlds may be — is still up for debate.

Yet the just-announced discovery of a rocky planet orbiting the nearest solar system to ours, the star Proxima Centauri, came as a surprise to many. Moreover, the finding suggests that Earth-like worlds could be far more common than we imagined.

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According to new research published on Jan. 15 in the journal Science Advances, a new exoplanet orbiting our closest stellar neighbor, Proxima c, is a viable candidate for being a “super-Earth” — the designation for rocky worlds slightly larger than Earth, yet without the huge gas envelope that encases gas giants like Saturn and Neptune. Those massive gas giants are believed to have rocky cores around the mass and shape of Earth, once you lift away the hydrogen and helium.

Proxima Centauri is a red dwarf star located 4.2 light years away from Earth. Though that is extremely close in astronomy terms, note that there are 5.88 trillion miles in one light-year, meaning it would take thousands of human years to travel such a distance. For comparison, Pluto, the most distant dwarf planet visited by a human spacecraft, orbits the sun at about 3.67 billion miles, or 5.5 light hours; the New Horizons probe that flew by Pluto took 9 years to travel there and is considered among the fastest-moving man-made objects ever to exist.

In any case, Proxima Centauri is the closest sun-like star we have to our solar system, meaning that once humans start sending out interstellar probes it is certain to be one of the first stars visited.

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In the paper, researchers from Italy and Greece propose that the closest super-Earth is not Proxima b, another planet orbiting Proxima Centauri which researchers discovered in 2016, but instead Proxima c. Researchers say that the existence of Proxima c is “highly significant for planet formation models.”

“This planet would be the one with the longest period and a minimum mass in the super-Earth regime presently detected with the [radial velocity] technique around a low-mass star,” the paper states. “It would also be the first at a distance from the parent star much larger than the expected original location of the snowline in the protoplanetary disk, which was within 0.15 AU.”

The “radial velocity technique” is a discovery method used by researchers to identify new worlds by tracking how their parent stars “wobble” in response to gravitational tugs from those planets. Beyond the “snowline” of the solar system means that any water on the planet would likely be frozen. The researchers estimate that Proxima c orbits its host star, Proxima Centauri, every 5.2 Earth years.

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“The formation of a super-Earth well beyond the snowline challenges formation models, according to which the snowline is a sweet spot for the accretion of super-Earths, due to the accumulation of icy solids at that location,” Mario Damasso, study author and postdoctoral researcher at Italy’s National Institute for Astrophysics, told CNN. “Or it suggests that the protoplanetary disk was much warmer than usually thought. In general, there’s nothing preventing the existence of Proxima c there where we spot it, but the formation and evolutionary history is a subject worthy of deeper investigation.”

The international team of researchers analyzed 17 years of data from the High Accuracy Radial Velocity Planet Searcher (HARPS) and the Ultraviolet and Visual Echelle Spectrograph (UVES) which are both part of the European Southern Observatory telescopes in Chile. They noticed that Proxima Centauri experienced an unknown wobble that could be the result of the gravitational pull of another planet, which came as a bit of a surprise.

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“Even the closest planetary system to us may retain interesting surprises,” Fabio Del Sordo, an author of the study and postdoctoral researcher in the department of physics at the University of Crete, told CNN. “Proxima Centauri hosts a planetary system that is much more complex than we knew, and we do not know how many unknown features are waiting to be discovered.”

As mentioned above, Proxima c isn’t the only exoplanet in Proxima Centauri’s solar system. In 2016, researchers discovered Proxima b, which is believed to have a similar mass to Earth, and an orbital period of 11 days. While it is also within Proxima Centauri’s habitable zone, it is tidally locked, which means only one side of the planet faces its sun. Tidally locked planets are less likely to be hospitable to life, as one side of these worlds would be very hot and the other extremely cold. However, some theorists believe that there may be a “ring” of habitability at the boundary between the hot and cold side, where the sky would appear to be in perpetual twilight, and within which life could theoretically thrive.

As Salon has previously reported, astronomers have catalogued 1,822 potential stars where Earth-like planets could exist. It seems like the chances are high that Earth’s twin exists somewhere, although it is questionable whether humans would ever be able to visit.

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Astronomers detect biggest explosion since Big Bang – DW (English)

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Researchers say the blast is the biggest since the universe began. It occurred at the center of a galaxy cluster some 390 million light years away from Earth.

Astronomers have discovered the biggest explosion seen in the universe, originating from a super-massive black hole.

The blast, they said, is the biggest explosion seen in the universe since the Big Bang. The explosion reportedly released five times more energy than the previous record holder.

Read moreWhat’s happening in the night sky in 2020?

The blast occurred at the center of the Ophiuchus cluster of galaxies, some 390 million light years away. The cluster is a conglomeration of thousands of galaxies, hot gas and dark matter bound together by gravity.

“We’ve seen outbursts in the centers of galaxies before but this one is really, really massive, ” said Melanie Johnston-Holitt, a professor at the International Center for Radio Astronomy Research (ICRAR). “And we don’t know why it’s so big.”

Read moreMercury creates tiny solar eclipse in rare celestial act

Astronomers used NASA’s Chandra X-Ray Observatory to make the discovery, as well as a European space observatory and ground telescopes. Scientists picked up the first sign of the explosion in 2016.

Chandra images of the cluster revealed an unusual curved edge, but scientists ruled out a possible eruption given the amount of energy that would have been needed to create such a large cavity of gas. The curviture was later confirmed to be a cavity.

According to ICRAR, the lead author of the study, Dr Simona Giacintucci from the Naval Research Laboratory in the United States, compared the blast to the 1980 eruption of Mount St. Helens, which tore the top off the mountain.

“The difference is that you can fit 15 Milky Way galaxies in a row into the crater this eruption punched into the cluster’s hot gas,” she said.

The blast is believed to be over by now, and, according to the research team, more observations are needed in other wavelengths to better understand what occurred.

Read moreMilky Way gobbled up smaller galaxy in cosmic crash, astronomers find

We made this discovery with Phase 1 of the MWA, when the telescope had 2048 antennas pointed towards the sky,” said Johnston-Hollitt. “We’re soon going to be gathering observations with 4096 antennas, which should be 10 times more sensitive. I think that’s pretty exciting.”

DW sends out a selection of the day’s news and features. Sign up for it here.

lc/aw (AP, EFE)

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Bright-Red "Blood Snow" Is Falling From the Sky in Antarctica – Futurism

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Blood Snow

A Facebook post by Ukraine’s Ministry of Education and Science shows a research station on an island just off the coast of Antarctica’s northernmost peninsula covered in “blood snow.”

The gory-looking scene is not the result of a seal hunt gone wrong — it’s an astonishingly red-pigmented, microscopic algae called Chlamydomonas nivalis, which thrives in freezing water as the ice melts during Antarctica’s record-breaking warm summer.

Algae Bloom

When summer hits the polar regions, the algae bloom, staining the snow and ice around it in blood-resembling red, as Live Science explains. The phenomenon was first noticed by Aristotle thousands of years ago and is often referred to as “watermelon snow” thanks to its subtly sweet scent and color.

What makes the blooming algae red is the same stuff that give carrots and watermelons their reddish tint — carotenoids.

Feedback Loop

It’s a stunning display of a natural phenomenon — but it also creates a nasty feedback loop that causes the ice to melt faster. The red color causes less sunlight to be reflected off the snow, causing it to melt faster, as the Ukrainian team explains in its post. The accelerated melting then causes more algae to grow, completing the cycle.

It’s not the only surreal display in the world caused by such a feedback loop, as Live Science points out. Blooming algae caused sea foam to swallow up the coast of a Spanish town in January. Similar algae blooms even caused shores around islands in the East China Sea to glow blue.

READ MORE: Spooky ‘blood snow’ invades Antarctic island [Live Science]

More on algae: A New Bioreactor Captures as Much Carbon as an Acre of Trees

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Scientists detect biggest explosion since Big Bang – BBC News

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Scientists have detected evidence for a colossal explosion in space – five times bigger than anything observed before.

The huge release of energy is thought to have emanated from a supermassive black hole some 390 million light years from Earth.

The eruption is said to have left a giant dent in the Ophiuchus galaxy cluster.

Researchers reported their findings in The Astrophysical Journal.

They had long thought there was something strange about Ophiuchus galaxy cluster, which is a giant aggregation containing thousands of individual galaxies intermingled with hot gas and dark matter. X-ray telescopes had spied a curious curved edge to it.

The speculation was that this might be the wall of a cavity that had been sculpted in its gas by emissions from a central black hole.

Black holes are famous for gorging on infalling matter, but they will also expel prodigious amounts of material and energy in the form of jets.

Scientists at first doubted their explanation however, because the cavity was so big; you could fit 15 of our own Milky Way galaxies in a row into the hole.

And that meant any black hole explosion would have to have been unimaginably prodigious.

But new telescope data from the Murchison Widefield Array (MWA) in Australia and the Giant Metrewave Radio Telescope (GMRT) in India seem to confirm it.

“In some ways, this blast is similar to how the eruption of Mount St Helens (volcano) in 1980 ripped off the top of the mountain,” said Simona Giacintucci of the Naval Research Laboratory in Washington, DC, and lead author of the study.

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