Astro Blog

Source:   By Dennis Overbye, The New York Times Excerpt: A prime planet listing has just appeared on the cosmic real estate market, possibly the most promising place yet to search for signs of life beyond the solar system, the astronomers who discovered it say. It is a rocky orb about one and a half times the size of Earth, about 40 light years from here. It circles a dwarf star known as LHS 1140 every 25 days, an orbit that puts it in the “Goldilocks” zone where temperatures are conducive to liquid water and perhaps life as we know it. It is close enough that astronomers are hopeful that with the next generation of big telescopes, they will be able to probe its atmosphere for signs of water or other evidence of suitability for life. “This planet is really close to us: If we shrank the Milky Way to the size of the United States, LHS 1140 and the sun would fit inside Central Park,” David Charbonneau, of the Harvard-Smithsonian Center for Astrophysics, said in an email. His colle...

Source:   By Paul Voosen, Science 2017-04-13. . . For GSS A Changing Cosmos chapter 7. Excerpt: In 2005, NASA’s Cassini spacecraft spied jets of water ice and vapor erupting into space from fissures on Enceladus, evidence of a salty ocean beneath the saturnian moon’s placid icy surface. Now, it turns out that the jets contain hydrogen gas, a sign of ongoing reactions on the floor of that alien sea. Because such chemistry provides energy for microbial life on Earth, the discovery makes Enceladus the top candidate for hosting life elsewhere in the solar system—besting even Jupiter’s Europa, another icy moon with an ocean. “We didn’t see microbes,” says Hunter Waite, a planetary scientist at the Southwest Research Institute in San Antonio, Texas, and the lead author of a study published this week in Science. “But we saw their food.”... http://www.sciencemag.org/news/2017/04/food-microbes-abundant-enceladus

Source:   By Jet Propulsion Laboratory News Excerpt:  A relatively large near-Earth asteroid discovered nearly three years ago will fly safely past Earth on April 19 at a distance of about 1.1 million miles (1.8 million kilometers), or about 4.6 times the distance from Earth to the moon. Although there is no possibility for the asteroid to collide with our planet, this will be a very close approach for an asteroid of this size. The asteroid, known as 2014 JO25, was discovered in May 2014 by astronomers at the Catalina Sky Survey near Tucson, Arizona -- a project of NASA's NEO Observations Program in collaboration with the University of Arizona. (An NEO is a near-Earth object). Contemporary measurements by NASA's NEOWISE mission indicate that the asteroid is roughly 2,000 feet (650 meters) in size, and that its surface is about twice as reflective as that of the moon. ...Small asteroids pass within this distance of Earth several times each week, but this upcoming close appr...