Astro Blog

https://news.berkeley.edu/2019/12/04/parker-probe-traces-solar-wind-to-its-source-on-suns-surface Source:    By Robert Sanders, UC Berkeley News. Excerpt: A year ago, NASA’s Parker Solar Probe flew closer to the sun than any satellite in history, collecting a spectacular trove of data from the very edge of the sun’s million-degree corona. ...that data has allowed solar physicists to map the source of a major component of the solar wind that continually peppers Earth’s atmosphere, while revealing strange magnetic field reversals that could be accelerating these particles toward our planet. These accelerated particles interact with Earth’s magnetic field, generating the colorful northern and southern lights. But they also have the potential to damage the electrical grid and telecommunications networks on Earth’s surface, threaten orbiting satellites and perhaps endanger astronauts in space. ...“There was a major space weather event in 1859 that blew out telegraph networks on...

https://eos.org/articles/meet-hygiea-the-smallest-dwarf-planet-in-our-solar-system Source:   By Javier Barbuzano, Eos/AGU. Excerpt: Around 2 billion years ago, two large rock bodies hit each other in the main asteroid belt, a region between the orbits of Mars and Jupiter populated by fragments of rocks of various sizes. The impactor, with a size ranging from 75 to 150 kilometers in diameter, hit a body at least 4 times larger. Astronomers have known about this impact for a long time because it created a whole family of asteroids in the main asteroid belt, formed by the celestial body Hygiea and almost 7,000 smaller asteroids that have similar orbits. Hygiea itself has been considered an asteroid since it was discovered in 1849 by Italian astronomer Annibale de Gasparis. With a diameter just over 430 kilometers, it is the fourth-largest object in the main asteroid belt. New observations obtained with the Very Large Telescope (VLT), located in Chile and operated by the European ...

https://eos.org/research-spotlights/curiosity-rover-reveals-oxygen-mystery-in-martian-atmosphere Source:   By Sarah Stanley, Eos/AGU. Excerpt: The Martian atmosphere is thin and cold and consists mostly of carbon dioxide. Although certainly unsuitable for humans, Martian air could hold clues to whether other life-forms live—or once lived—on the Red Planet. Now Trainer et al. report the first measurements of the five major components of the Martian atmosphere captured over several seasonal cycles. ...On average, the data revealed, the equatorial Martian atmosphere consists of 95% carbon dioxide, 2.59% nitrogen, 1.94% argon, 0.161% oxygen, and 0.058% carbon monoxide. However, throughout the year, some of these concentrations vary widely because of seasonal freezing of carbon dioxide at the planet’s poles, which periodically removes much of this gas from the atmosphere. Seasonal polar freezing—and subsequent thawing—of carbon dioxide also causes atmospheric pressure to rise and fa...

https://www.sciencemag.org/news/2019/11/how-enceladus-got-its-water-spewing-tiger-stripes Source:   By Adam Mann, Science Magazine. Excerpt: Researchers say they have solved a long-standing mystery about Saturn’s tiny, frozen moon Enceladus: why its south pole features long, water-spewing geysers known as tiger stripes. The study could also help explain why these unique formations aren’t seen on any other satellite in the solar system. Enceladus became a star attraction in 2005, when NASA’s Cassini mission photographed enormous jets of water ice and vapor emanating from four parallel slashes near its south pole. Since then, researchers have detected organic molecules and hydrogen in the jets—potential food for microbes—making Enceladus one of the top destinations in the search for life elsewhere in the Solar System. ...As it orbits around Saturn, Enceladus experiences gravitational tidal forces that squeeze and heat it. ...According to the new study, led by Douglas Hemingway of...

https://www.nytimes.com/2019/11/04/science/voyager-2-interstellar-solar-wind.html Source:   By Kenneth Chang. The New York Times. Excerpt: The Voyager 2 spacecraft burst out of the bubble of gases expanding from the sun and into the wild of the Milky Way a year ago. It was the second spacecraft to cross that boundary and directly observe the interstellar medium. Its faster-moving twin, Voyager 1, made the crossing six years earlier, in August 2012. Launched 42 years ago, when Jimmy Carter was president, the twin spacecraft have persisted far longer than envisioned, as has their ability to send scientific findings home to Earth. In a series of papers published on Monday in Nature Astronomy [https://www.nature.com/articles/s41550-019-0928-3], scientists report what Voyager 2 observed at the boundary of the solar wind’s bubble and beyond....

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...