Astro Blog

https://www.sciencemag.org/news/2019/09/veil-dust-ancient-asteroid-breakup-may-have-cooled-earth Source:   By Joshua Sokol, Science Magazine. Excerpt: Faced with a dangerously warming world, would-be geoengineers have dreamed up ways to quickly turn down the heat. One proposed technique: spreading a veil of dust that would sit in space or Earth's atmosphere and reflect sunlight. Researchers say they have now found evidence for a similar experiment that played out naturally, 466 million years ago, when an asteroid out in space exploded into bits. Dust from the breakup blanketed the planet, says Birger Schmitz, a geologist at Lund University in Sweden, plunging it into an ice age that was soon followed by an explosion in animal life. The ancient episode offers both encouragement and caution for geoengineers. If Schmitz is right, it dramatically demonstrates how dust can cool the planet. But the deep freeze is a lesson in potential unintended consequences....

https://www.bbc.com/news/science-environment-49648746 Source:   By Pallab Ghosh, BBC News. Excerpt: Astronomers have for the first time discovered water in the atmosphere of a planet orbiting within the habitable zone of a distant star. The finding makes the world - which is called K2-18b - a plausible candidate in the search for alien life. ...Details were published in the scientific journal Nature Astronomy [ https://www.nature.com/articles/s41550-019-0878-9 ]. ...K2-18b is 111 light-years - about 650 million million miles - from Earth, too far to send a probe. ...The team behind the discovery looked through the planets discovered by the Hubble Space Telescope between 2016 and 2017. The researchers determined some of the chemicals in their atmosphere by studying the changes to the starlight as the planets orbited their suns. The light filtered through the planets' atmospheres was subtly altered by the composition of the atmosphere.Only K2-18b revealed  the molecular sign...

https://www.nytimes.com/2019/08/19/science/antarctica-snow-supernova.html Source:   By Katherine Kornei, The New York Times. Excerpt: Earth is continuously plowing through extraterrestrial dust. Tens of thousands of tons of the stuff, mostly from asteroids and comets, settles all over the planet every year. ...Recently, scientists analyzed dust collected from Antarctic snow and found an excess of radioactive iron. After ruling out contamination from nuclear weapons testing and other sources, the team concluded that the iron was produced by supernovas, fleeting explosions of stars more massive than the sun. This discovery suggests that stellar blasts might have rocked Earth and the rest of the solar system in the not-too-distant past. The results were published on Aug. 12 in Physical Review Letters [ https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.123.072701 ]. Meteorite hunters are drawn to Antarctica because the space rocks, which are dark, stand out against the snow...

https://www.nasa.gov/image-feature/artemis-1-map Source:   NASA.

https://news.berkeley.edu/story_jump/jupiters-annual-portrait-is-a-beaut/ Source:   By Robert Sanders, UC Berkeley News. Excerpt: Just as families record the changing faces of their kids as they grow older, the Hubble Space Telescope each year captures the changing faces of the solar system’s four colorful gas-giant planets. The newest photo in that yearbook is a portrait of Jupiter taken June 27 that reveals clouds swirling in the planet’s turbulent atmosphere that are painted with a color palette more intense than seen in previous years. Mike Wong, an associate researcher in UC Berkeley’s Department of Astronomy and one of three members of the Hubble team taking the photos, was most intrigued by a mysterious color change around Jupiter’s equator: The formerly white equatorial belt has become orangish. And, surprisingly, Red Spot Jr., a planet that was red the last time it was photographed, has turned white. It is now back to the way it looked at its formation in 2000, before ...

https://www.nytimes.com/2019/07/30/science/mars-tsunami-crater.html Source:   By Robin George Andrews, New York Times.   Excerpt: A new study, published last month in the Journal of Geophysical Research: Planets, suggests that a 75-mile-wide impact scar in the Martian northern lowlands is to the red planet what the Chicxulub crater is to Earth: the mark of a meteor that generated a mega-tsunami when the planet was relatively young. If accurate, the finding adds evidence to the hypothesis that Mars once had an ocean, and would have implications for our search for life there....

https://www.nytimes.com/2019/07/29/science/nasa-tess-exoplanets-astronomy.html See also Newly discovered exoplanet trio could unravel the mysteries of super-Earth formation in Science Magazine . [ https://www.sciencemag.org/news/2019/07/newly-discovered-exoplanet-trio-could-unravel-mysteries-super-earth-formation ] Source:   By Dennis Overbye, New York Times. Excerpt: NASA’s new planet-hunting spacecraft, the Transiting Exoplanet Survey Satellite, is now halfway through its first tour of the nearby universe. It has been looking for worlds that might be fit for you, me or some other form of life, and as usual, nature has been generous in its rewards. Since its launch in April 2018, TESS has already discovered 21 new planets and 850 more potential worlds that have yet to be confirmed, all residing within a few dozen light years of the sun and our own solar system, according to George Ricker, an M.I.T. researcher who heads the TESS project. So far, he said, TESS “has far exceeded...