Showing posts from 2021

‘Hubble is back!’ Famed space telescope has new lease on life after computer swap appears to fix glitch Source: By  Daniel Clery .  Excerpt: The iconic but elderly Hubble Space Telescope appears to have been resurrected again after a shutdown of more than a month following a computer glitch. Science has learned that following a switch from the operating payload control computer to a backup device over the past 24 hours, Hubble’s operators have re-established communications with all the telescope’s instruments and plan to return them to normal operations today.... 

Exploding stars may have assaulted ancient Earth Source: By  Daniel Clery , Since Magazine.  Excerpt: ...Over the past 2 decades, researchers have found hundreds of radioactive atoms, trapped in seafloor minerals, that came from an ancient explosion marking the death of a nearby star. Its fusion fuel exhausted, the star had collapsed, generating a shock wave that blasted away its outer layers in an expanding ball of gas and dust so hot that it briefly glowed as bright as a galaxy—and ultimately showered Earth with those telltale atoms. Erupting from hundreds of light-years away, the flash of x-rays and gamma rays probably did no harm on Earth. But the expanding fireball also accelerated cosmic rays—mostly nuclei of hydrogen and helium—to close to the speed of light. These projectiles arrived stealthily, decades later, ramping up into an invisible fusillade that could have lasted for thousands of years and might have affected the atmosphere—and li

Gap in Exoplanet Size Shifts with Age. Source: By  Katherine Kornei , Eos/AGU.  Excerpt: Smaller planets are scarcer in younger systems and larger planets are lacking in older systems, according to new research that analyzed hundreds of exoplanets. ...Planets just a bit larger than Earth appear to be relatively rare in the exoplanet canon. A team has now used observations of hundreds of exoplanets to show that this planetary gap isn’t static but instead evolves with planet age—younger planetary systems are more likely to be missing slightly smaller planets, and older systems are more apt to be without slightly larger planets. This evolution is consistent with the hypothesis that atmospheric loss—literally, a planet’s atmosphere blowing away over time—is responsible for this so-called “radius valley,” the researchers suggested....

Fifteen Years of Radar Reveal Venus’s Most Basic Facts Source: By  Kimberly M. S. Cartier , Eos/AGU .  Excerpt: Venus’s heavy atmosphere tugs the planet’s surface enough to change the length of its day by up to 21 minutes [per day]. ...In a recent paper in  Nature Astronomy , astronomers used 15 years of radar measurements to reveal a few of these fundamental properties of our closest planetary neighbor that have long remained elusive. ...The 70-meter radio antenna at the  Goldstone Deep Space Communications Complex  in California served as the flashlight, ...The researchers carefully measured the timing of the returned waves with two radio telescopes: Goldstone in California and the  Green Bank Telescope  in West Virginia. ...they found that Venus’s spin axis is tilted 2.6392° from its orbital plane and that tilt precesses once every 29,000 Earth years, 3,000 years longer than Earth’s precession. These measurements are 5–15 times more precise than what was achi

Record-Setting Flare Spotted on the Nearest Star to the Sun. Source: By  Katherine Kornei , Eos/AGU.  Excerpt: As stellar neighbors go, the Sun is a pretty good one—it occasionally produces a sizeable solar flare, but mostly, it leaves Earth well enough alone. The Proxima Centauri solar system isn’t so lucky, however: Blasts of electromagnetic radiation from Proxima Centauri, the next nearest star to our own, can be potentially lethal to nearby planets. Researchers recently spotted the brightest stellar flare ever detected from Proxima Centauri. That flare might have contributed to stripping away the atmosphere of one of its planets, a roughly Earth mass world that potentially hosts liquid water on its surface. ...Destroyer of Atmospheres ...Proxima Centauri’s faintness stems from its low mass—it’s what astronomers refer to as an M dwarf star, defined as having a mass between roughly 10% and 50% the mass of the Sun. M dwarf stars are the most common stars in the

China lands rover on Mars in ‘milestone’ achievement Source: By   Antonia Noori Farzan , The Washington Post.  Excerpt: China successfully landed a rover-carrying spacecraft on Mars for the first time, state-run media reported Saturday, marking another major victory for the country’s ambitious space program.... China now joins the United States as the only other nations to have successfully landed and operated rovers on Mars, and Chinese President Xi Jinping hailed a   “milestone”  achievement. The Tianwen-1 spacecraft, launched from the Chinese province of Hainan in July, has been orbiting Mars since February while looking for potential landing sites. Early Saturday, it released an entry capsule containing a lander and a rover that began to plummet through the Mars atmosphere, according to   state-run Xinhua News Agency . The entry capsule safely touched down in a flat plane on Mars’ surface at 7:18 a.m. Beijing time (7:18 p.m. Friday Eastern time), though it took about a

NASA Mars Helicopter Makes One-Way Flight to New Mission Source: By  Kenneth Chang , The New York Times.  Excerpt: On Friday, Ingenuity, which last month became the first machine to fly like an airplane or a helicopter on another world, took off for the fifth time. It made a successful one-way trip to another flat patch of Mars more than the length of a football field away. The spot where it landed will serve as its base of operations for the next month at least, beginning a new phase of the mission where it will serve as a scout for its larger robotic companion, the Perseverance rover....  

NASA’s Mars Helicopter Completes First Flight on Another Planet Source:  By  Kenneth Chang , The New York Times.  Excerpt: A small robotic helicopter named Ingenuity made space exploration history on Monday when it lifted off the surface of Mars and hovered in the wispy air of the red planet. It was the first machine from Earth ever to fly like an airplane or a helicopter on another world. ...Like the first flight of an airplane by Wilbur and Orville Wright in 1903, the flight did not go far or last long, but it showed what could be done. Flying in the thin atmosphere of Mars was a particularly tricky technical endeavor, on the edge of impossible because there is almost no air to push against. NASA engineers employed ultralight materials, fast-spinning blades and high-powered computer processing to get Ingenuity off the ground and keep it from veering off and crashing....   See also April 22 NY Times article,  NASA’s Mars Ingenuity Helicopter Completes Second Flight .

Remains of impact that created the Moon may lie deep within Earth Source:    By  Paul Voosen .  Excerpt: Scientists have long agreed that the Moon formed when a protoplanet, called Theia, struck Earth in its infancy some 4.5 billion years ago. Now, a team of scientists has a provocative new proposal: Theia’s remains can be found in two continent-size layers of rock buried deep in Earth’s mantle. For decades, seismologists have puzzled over these two blobs, which sit below West Africa and the Pacific Ocean and straddle the core like a pair of headphones. Up to 1000 kilometers tall and several times that wide, “they are the largest thing in the Earth’s mantle,” says Qian Yuan, a Ph.D. student in geodynamics at Arizona State University (ASU), Tempe. Seismic waves from earthquakes abruptly slow down when they pass through the layers, which suggests they are denser and chemically different from the surrounding mantle rock. ...Evidence from Iceland and Samoa sug

The Water on Mars Vanished. This Might Be Where It Went Source:  By  Kenneth Chang , The New York Times.  Excerpt: Mars once had rivers, lakes and seas. Although the planet is now desert dry, scientists say most of the water is still there, just locked up in rocks. ...most of the water, a new study concludes, went down, sucked into the red planet’s rocks. And there it remains, trapped within minerals and salts. Indeed, as much as 99 percent of the water that once flowed on Mars could still be there, the researchers estimated in  a paper published this week in the journal Science.  Data from the past two decades of robotic missions to Mars, including NASA’s Curiosity rover and the Mars Reconnaissance Orbiter, showed a wide distribution of what geologists call hydrated minerals.... 

Martian rover sends back ‘overwhelming’ video, audio from the Red Planet Source:    By   Catherine Matacic , Science Magazine.  Excerpt: Just four martian days after   touching down on the Red Planet , NASA’s Perseverance rover has sent back its first video of its new home: a 1-minute arabesque of color and motion captured from four on-board cameras, as the car-size rover dangles from its rocket-propelled descent vehicle, a red-and-white parachute snaps into place, and the pitted surface of Mars comes slowly into view, dark canyons giving way to ripples of dust that look like giant, rust-colored dunes (see video, above). But perhaps even more thrilling, an unexpected gift arrived along with the video and the   thousands of new images   that were downloaded over the weekend: the   first sound recording   taken from the surface of Mars....  See also   Perseverance’s ‘sky crane’ captures Mars descent .

‘Touchdown confirmed!’ Perseverance landing marks new dawn for Mars science Source:    By   Paul Voosen , Science Magazine.  Excerpt: It’s a new day on Mars. NASA’s $2.7 billion Perseverance rover has successfully landed in Jezero crater, alighting just 35 meters away from hazardous boulders it had identified during descent. At about 3:55 p.m. EST, confirmation came back of the rover safely touching its wheels down, resulting in exuberant but socially distanced applause from double-masked engineers at the mission’s control room at the Jet Propulsion Laboratory (JPL)....   See also   Perseverance’s ‘sky crane’ captures Mars descent ; and New York Times article   Perseverance’s Pictures From Mars Show NASA Rover’s New Home .

Martian New Year on Sunday a second chance to start fresh, Earthling Source:  By Chris Knight, The Telegram.  Excerpt: ...Feb. 7 [2021] marks the beginning of [Martian] year 36. Back at the turn of the (Earth) century ...scientists decided they needed a way to count Martian years. Earth years wouldn’t do, since Mars takes 687 days to circle the sun. They picked the Martian spring equinox of 1955 as the start of year one. ...Mars, like Earth, has an elliptical orbit that brings it closer to the sun at certain points of the year. It also has an axial tilt of 25 degrees. (Earth’s is just over 23.) Together this creates seasons, with variations in temperature, sunlight and even air pressure, since some of the thin carbon dioxide atmosphere freezes at the poles in the winter. ...the overlap of tilt and orbit means northern Martian winters are significantly milder than in the south, with repercussions on any rovers operating in th

An Asteroid “Double Disaster” Struck Germany in the Miocene Source:  By  Katherine Kornei , Eos/AGU.  Excerpt: A Gothic church rises high above the medieval town of Nördlingen, Germany. But unlike most churches, St. George’s is composed of a very special type of rock:  suevite , a coarse-grained breccia that’s formed only in powerful impacts. That discovery and  other lines of evidence  have helped researchers determine that Nördlingen lies within an impact crater. Now, scientists have unearthed evidence that this crater and another one just 40 kilometers away were formed by a “double disaster” of two independent asteroid impacts. ...Our planet is dotted with  nearly 200 confirmed impact structures , and a handful of them appear in close pairs. Some researchers have proposed that these apparent double craters are scars created by  binary asteroids  slamming into Earth at the same time. ...However, scientists have theoretically determined that the binary asteroi