Astro Blog

Source:   By Carolyn Gramling, Science. Also NASA, Cassini. 2015-10-30. Cassini samples an alien ocean. For GSS A Changing Cosmos chapter 7. Excerpt: NASA’s Cassini spacecraft has just sent back the first pictures from its deep plunge toward the surface of icy Enceladus, a flyby that took it through one of the moon’s geysers. ...Since Cassini began its flybys of Saturn and its moons in 2005, scientists have learned that beneath the layer of ice is a global ocean about 10 kilometers thick that may harbor life and probably contains hydrothermal vents. They have spotted more than 100 huge geysers of ice particles, water vapor, and organic molecules spewing from fractures in the ice covering Enceladus’s south polar region. These plumes shoot the contents of the moon’s subglacial ocean hundreds of kilometers high, in eruptions that may resemble curtains rather than columns. This week, the spacecraft made its deepest dive into one such plume—just 49 kilometers above the moon’s surfac...

Source:   NASA [Youtube video] NASA's Cassini Spacecraft is about to make a daring plunge through one of the plumes emerging from Saturn's moon Enceladus. https://www.youtube.com/watch?v=nts-bkhoMt4&feature=youtu.be

Source:   NASA Release 15-213 Excerpt: ...NASA's ARRM [Asteroid Redirect Robotic Mission] spacecraft will need to be able to demonstrate support of high power solar electric propulsion, with initial solar array power of approximately 50 kilowatts. The robotics capture system planned aboard the pioneering vehicle will be capable of acquiring a 20 ton (or larger) boulder of up to about 19 feet (six meters) in width from an asteroid's surface and then returning it to an astronaut-accessible orbit near our moon. ...The spacecraft will need to be ready for launch by the end of 2020. ...While at a large asteroid, the spacecraft will demonstrate a "slow-push" planetary defense asteroid deflection technique during the mission. This uses the spacecraft and boulder's combined gravitational pull to attempt to change the course of an asteroid.... http://www.nasa.gov/press-release/nasa-calls-for-american-industry-ideas-on-arm-spacecraft-development

Source:   NASA Release 15-199 Excerpt: NASA launched a new website Monday so the world can see images of the full, sunlit side of the Earth every day. The images are taken by a NASA camera one million miles away on the Deep Space Climate Observatory (DSCOVR), a partnership between NASA, the National Oceanic and Atmospheric Administration (NOAA) and the U.S. Air Force. Once a day NASA will post at least a dozen new color images of Earth acquired from 12 to 36 hours earlier by NASA’s Earth Polychromatic Imaging Camera (EPIC). Each daily sequence of images will show the Earth as it rotates, thus revealing the whole globe over the course of a day. The new website also features an archive of EPIC images searchable by date and continent.... http://www.nasa.gov/press-release/daily-views-of-earth-available-on-new-nasa-website

Source:   By S. A. Stern1, F. Bagenal, et al, Science. Abstract: The Pluto system was recently explored by NASA’s New Horizons spacecraft, making closest approach on 14 July 2015. Pluto’s surface displays diverse landforms, terrain ages, albedos, colors, and composition gradients. Evidence is found for a water-ice crust, geologically young surface units, surface ice convection, wind streaks, volatile transport, and glacial flow. Pluto’s atmosphere is highly extended, with trace hydrocarbons, a global haze layer, and a surface pressure near 10 microbars. Pluto’s diverse surface geology and long-term activity raise fundamental questions about how small planets remain active many billions of years after formation. Pluto’s large moon Charon displays tectonics and evidence for a heterogeneous crustal composition; its north pole displays puzzling dark terrain. Small satellites Hydra and Nix have higher albedos than expected....  For latest images from New Horizons Mission to Plu...

Source:  Steven K. Blau, Physics Today Excerpt: 2015-10-12. Enceladus’s subsurface ocean wraps the moon. By Steven K. Blau, Physics Today. For GSS A Changing Cosmos chapter 7. Excerpt: The satellite’s response to torque applied by Saturn shows that its icy surface and silicate core are not attached. A decade ago the Cassini orbiter spotted gas and ice spewing from the south polar region of Saturn’s moon Enceladus. Subsequent investigations revealed that the ice is salty, a result indicating that the ice originated from a liquid ocean between Enceladus’s frozen surface and its silicate core. Now Peter Thomas (Cornell University) and his colleagues have analyzed more than seven years of Cassini surface observations and shown that the ocean is not localized at the polar region of Enceladus; rather, it is global....  URL 0 http://scitation.aip.org/content/aip/magazine/physicstoday/news/10.1063/PT.5.7210