Showing posts from March, 2018

NASA’s new satellite brings the search for Earthlike exoplanets closer to home Source:   By Daniel CleryMar, Science. Excerpt: Thanks to NASA's pioneering Kepler probe, we know our galaxy is teeming with exoplanets ...more than 2600 confirmed exoplanets, implying hundreds of billions in the Milky Way. The new efforts Earth-size planets whose composition, atmosphere, and climate—factors in whether they might be hospitable to life—could be studied. Leading the charge is the Transiting Exoplanet Survey Satellite (TESS), a NASA mission due for launch on 16 April. The brainchild of researchers at the Massachusetts Institute of Technology (MIT) in Cambridge, the $337 million TESS project aims to identify at least 50 rocky exoplanets—Earth-size or bigger—close enough for their atmospheres to be scrutinized by the much larger James Webb Space Telescope (JWST), due for launch in 2020. ...Like Kepler, TESS finds planets by staring at stars and looking

Surprising meteorite discovery points to early solar system chaos Source:   By Paul VoosenMar, Science. Excerpt: The stately solar system of today was in turmoil in its first several million years, theorists believe, with giant planets sowing chaos as they strayed far from their current orbits. But corroborating evidence has been thin—until now. Scientists have found a new window into the early dynamics: a curious chemical divide in the dozens of species of meteorites. work presented last week at the Lunar and Planetary Science Conference here, a group of German geochemists ...tested 32 meteorites representing nearly all known types and found that "any meteorite you take, it belongs to either one of these groups," says Thorsten Kleine, a geochemist at the University of Münster in Germany who led the work. Those divergent chemistries imply distinct origin stories for asteroids, the parent bodies of most meteorites. One group formed

Meet TESS, Seeker of Alien Worlds Source:   By Dennis Overbye, The New York Times. For GSS A Changing Cosmos chapter 8. Excerpt: ...No earlier than 6:32 p.m. on April 16, ...a little spacecraft known as the Transiting Exoplanet Survey Satellite, or TESS, bristling with cameras and ambition, will ascend on a SpaceX Falcon 9 rocket in a blaze of smoke and fire and take up a lengthy residence between the moon and the Earth. There it will spend the next two years, at least, scanning the sky for alien worlds. TESS is the latest effort to try to answer questions that have intrigued humans for millenniums and dominated astronomy for the last three decades: Are we alone? Are there other Earths? Evidence of even a single microbe anywhere else in the galaxy would rock science. ...“Most of the stars with planets are far away,” said Sara Seager, a planetary scientist at the Massachusetts Institute of Technology and a member of the TESS team, referring to Kepler

Mars’ oceans formed early, possibly aided by massive volcanic eruptions Source:   By Robert Sanders, UC Berkeley News. For GSS A Changing Cosmos chapter 7. Excerpt: A new scenario seeking to explain how Mars’ putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million years earlier and were not as deep as once thought. ...The proposal by UC Berkeley geophysicists links the existence of oceans early in Mars history to the rise of the solar system’s largest volcanic system, Tharsis, and highlights the key role played by global warming in allowing liquid water to exist on Mars. “Volcanoes may be important in creating the conditions for Mars to be wet,” said Michael Manga, a UC Berkeley professor of earth and planetary science and senior author of a paper appearing in Nature this week and posted online March 19. Those claiming that Mars never had oceans of liquid water often point to the fact that e

Jupiter’s chaotic storms have roots deep beneath its surface Source:   By Paul Voosen, Science. Excerpt: The gaseous veil of Jupiter’s surface has long cast a pall over scientists’ quest to understand the giant planet’s depths. In particular, researchers have debated whether the bands of east-west winds ...extend deeper into the planet, or are merely superficial. Now, a series of papers from NASA’s Juno spacecraft, published today in Nature, has revealed that the roots of Jupiter’s winds indeed run deep. ...Juno’s scientists discovered an asymmetry in Jupiter’s north-south gravitational field that reflected shifting masses driven by rising winds from 3000 kilometers deep within the planet. These flows of hydrogen and helium, the team shows, are driven up by energy lost from the planet’s deeper interior, which rotates like a solid because of crushing high pressures....    See also Scientific American article: