Astro Blog

https://www.sciencemag.org/news/2021/03/remains-impact-created-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 Ic...

https://www.nytimes.com/2021/03/19/science/mars-water-missing.html 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.... 

https://www.sciencemag.org/news/2021/02/martian-rover-sends-back-overwhelming-video-audio-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 .

https://www.sciencemag.org/news/2021/02/touchdown-confirmed-perseverance-landing-marks-new-dawn-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 .

https://www.thetelegram.com/lifestyles/entertainment/martian-new-year-on-sunday-a-second-chance-to-start-fresh-earthling-549591/ 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 operat...

https://eos.org/articles/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 theo...

https://www.sciencemag.org/news/2020/12/china-lands-its-moon-rocks-inner-mongolia Source:  By   Paul Voosen , Science Magazine.  Excerpt: China’s Chang’e-5 mission made a triumphant return around 1 p.m. EST today, landing in the middle of the night on the dark frozen plains of Inner Mongolia, Chinese   state media reported . The capsule’s return marks the first time China has collected rocks from the Moon—and the first time any nation has accomplished the feat since 1976. The 3-week-long mission   was the most complicated   in the history of China’s robotic space exploration program, involving a lunar landing, furious scooping and drilling of up to 2 kilograms of grit, and then an ascent and rendezvous with an orbiter, which carried the samples back to Earth. The China National Space Administration, typically secretive with its missions, showed growing confidence in its space program, with live broadcasts of the rocket launch and return of its sample caps...