Space & Astronomy

Subterms

    More stories

    • 175 Shares199 Views

      in Space & Astronomy

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

      by

      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

    • 163 Shares129 Views

      in Space & Astronomy

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

      by

      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

    • 113 Shares99 Views

      in Space & Astronomy

      The North Star is much heavier than previously thought

      by

      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

      in Space & Astronomy

      Sulfur was key to the first water on Earth

      by

      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

    • 175 Shares169 Views

      in Space & Astronomy

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

      by

      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

    • 113 Shares179 Views

      in Space & Astronomy

      Strange observations of galaxies challenge ideas about dark matter

      by

      Head-scratching observations of distant galaxies are challenging cosmologists’ dominant ideas about the universe, potentially leading to the implication that the strange substance called dark matter doesn’t exist.

      That’s one possible conclusion from a new study published June 20 in The Astrophysical Journal Letters. The finding “raises questions of an extraordinarily fundamental nature,” says Richard Brent Tully, an astronomer at the University of Hawaii at Manoa who was not involved in the work.

      Astronomers suspect dark matter exists because of the way stars and other visible material at a galaxy’s visible edge rotate. The rotation speeds of objects far from a galactic center are much higher than they should be given the amount of luminous stuff seen in telescopes. Under physicists’ current understanding of gravity, this implies that a massive reservoir of invisible matter must be tugging on those stars. More

    • 188 Shares189 Views

      in Space & Astronomy

      A stellar explosion may add a temporary ‘new star’ to the night sky this summer

      by

      Keep your eyes on the night sky this summer, scanning for the constellation Corona Borealis, and if you are lucky, you may glimpse what appears to be a new star winking on in the dark.

      The brightening point of light will not be a new star, but a nova eruption about 3,000 light-years from Earth. There, a white dwarf star orbiting a red giant tears material from its larger companion. When enough mass collects on the white dwarf’s surface, the rising pressure and temperature will trigger a blast that can be seen from Earth with the naked eye — but for only a few days to a week. More

    • 125 Shares179 Views

      in Space & Astronomy

      We may finally know the source of mysterious high-energy neutrinos

      by

      Supermassive black holes at the hearts of active galaxies may be churning out a lot of the universe’s high-energy neutrinos.

      Two teams using data from IceCube, the world’s premier neutrino observatory located in Antarctica, have independently identified a common type of these active galaxies, called Seyfert galaxies, as likely neutrino producers. These findings, reported in Physical Review Letters and arXiv.org, bolster some astronomers’ view that the cores of such active galaxies could churn out the majority of the cosmic neutrinos seen streaming across the universe. More