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      The historic ‘Wow!’ signal may finally have a source. Sorry, it’s not aliens

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      One of the most compelling potential signs of extraterrestrial communication might have an astrophysical explanation.

      Called the “Wow!” signal, the bright burst of radio waves has defied our understanding since its discovery in the 1970s. Now, scientists using archived data from the Arecibo Observatory in Puerto Rico suggest a new possible source for the signal: a cosmic hydrogen cloud that emitted light like a laser.

      “I think we have probably the best explanation so far,” says astrobiologist Abel Méndez of the University of Puerto Rico at Arecibo. Méndez, together with astrophysicist Kevin Ortiz Ceballos of the Harvard and Smithsonian Center for Astrophysics in Cambridge, Mass., and Jorge Zuluaga of the University of Antioquia, Colombia, submitted this idea to arXiv.org on August 16. More

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      The nearest midsized black hole might instead be a horde of lightweights

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      Contrary to a previous report, there’s no evidence of an intermediate-mass black hole in Omega Centauri, the Milky Way’s most massive and luminous globular star cluster, a new study finds. Instead, a hive of much smaller black holes diving into and out of the tightly packed star cluster’s center can explain the movement and distribution of its many ancient stars.

      “What we found in our analysis is that the data favor an extended component [of stellar-mass black holes] as opposed to an intermediate-mass black hole,” says Andrés Bañares-Hernández, an astronomer at the Instituto de Astrofísica de Canarias in La Laguna, Spain. Some 10,000 to 20,000 stellar-mass black holes — adding up to between 200,000 and 300,000 times the mass of the sun — that are spread around the center of the star cluster can explain the observations, he says. More

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      A distant quasar may be zapping all galaxies around itself

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      One of the farthest known quasars seems to have shut down the creation of new stars in all the galaxies within its vicinity.

      A quasar is a powerful source of light, created by torrid gas orbiting a gargantuan black hole at the center of a galaxy. The intense radiation from one quasar, named VIK J2348-3054, has probably stopped star formation at least 16 million light-years away from itself, astronomer Trystan Lambert and colleagues report in a paper to appear in Astronomy and Astrophysics. More

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      Some meteors leave trails lasting up to an hour. Now we may know why

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      To leave a lasting trail, meteors need to aim low. A new survey of shooting stars shows that meteors that blaze through 90 kilometers up in the sky leave a persistent afterglow, unlike those that burn up at greater heights.

      Meteors are normally blink-and-you’ll-miss-it events. A particle of space dust leaves a fiery trail of light as it zips through the atmosphere, and then it’s gone. But sometimes, a meteor leaves a lingering afterglow. Astronomers have noted these persistent trains for more than a century, but questions remained about their origins. More

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      NASA’s Perseverance rover finds its first possible hint of ancient life on Mars

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      NASA’s Perseverance rover has bagged its first hint of ancient microbes on Mars.

      “We’re not able to say that this is a sign of life,” says Perseverance deputy project scientist Katie Stack Morgan of NASA’s Jet Propulsion Lab in Pasadena, Calif.  “But this is the most compelling sample we’ve found yet.”

      The rover drilled up the sample on July 21 from a reddish rock, dubbed Cheyava Falls after a feature at the Grand Canyon. It is the first piece of Mars that Perseverance has examined that contains organic molecules, the building blocks of life, project scientist Ken Farley of Caltech reported July 25 at the 10th International Conference on Mars in Pasadena. More

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      The North Star is much heavier than previously thought

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      The star marking true north is a good deal heavier than we thought.

      The North Star is 5.1 times as massive as the sun, astronomers report in work submitted July 12 to arXiv.org. That value, calculated from the motion of a much fainter star that orbits the luminary, is nearly 50 percent heavier than a recent estimate of 3.45 solar masses.

      Mass profoundly affects stellar life: The more mass a star has, the faster it burns its fuel and the sooner it dies. The earlier mass estimate had suggested that the North Star, also known as Polaris, is roughly 100 million years old (SN/12/2/16). The new estimate means the star formed more recently than this, but no one has yet calculated a revised age. More

    • 113 Shares159 Views

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      Sulfur was key to the first water on Earth

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      A chemical element that’s not even in H2O — sulfur — is the reason Earth first got its water, a new study finds, bolstering a similar claim made a year ago. The discovery means our planet was born with all it needed to create its own water and so did not have to receive it from elsewhere.

      Water is essential to terrestrial life, but Earth formed in a region around the newborn sun that was so hot the planet should have been dry (SN: 5/6/15). Now two independent studies of a specific type of meteorite reach the same conclusion: Lots of hydrogen — a key component of water — came to Earth not as H2O but instead bonded with sulfur. This allowed the hydrogen to survive the heat and later join oxygen, the most common element in Earth’s crust, to create water. More

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      A middleweight black hole has been spotted for the first time in our galaxy

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      For the first time, astronomers have spotted a middleweight black hole in the nearby universe. The discovery could help solve the riddle of how even heftier black holes form and grow up with their host galaxies.

      The black hole, which sits about 16,000 light-years from Earth in the center of star cluster Omega Centauri, is at least 8,200 times as massive as the sun, putting it squarely in a rare category of intermediate-mass black holes, researchers report July 10 in Nature. More