Centauri Dreams 11 May 2018, 15:22 UTC The definition of a habitable zone is under constant refinement, an important line of research as we choose which exoplanets to focus on in our search for life. Centauri Dreams regular Alex Tolley today looks at the question as it involves the presence of methane. With planetary warming already known to vary depending on the spectral type of the host star, we now learn that the presence of methane can produce thermal inversions and surface cooling on M-star exoplanets, impacting the outer limits of the habitable zone. The work of Ramses Ramirez (Tokyo Institute of Technology) and Lisa Kaltenegger (Carl Sagan Institute, Cornell University), the paper also suggests a possible biosignature near the outer habitable zone edge of hotter stars, one of several results that Alex explores in today’s essay.
SPACE.com 11 May 2018, 11:25 UTC NASA and the Cassini team have given us another gorgeous blast from Saturn's past. The Cassini spacecraft orbited Saturn from the summer of 2004 until Sept. 15, 2017, when the low-on-fuel probe performed an intentional death dive into the ringed planet's cloud tops.
NASA Space Station Blog 10 May 2018, 19:33 UTC Two Expedition 55 Flight Engineers are using virtual reality and computer training today to prepare for next week’s spacewalk at the International Space Station. Robotics controllers from Houston and Japan are also maneuvering a pair of robotic arms for the upcoming spacewalk and satellite deployments.
Centauri Dreams 10 May 2018, 17:26 UTC Looking for biological products in planetary atmospheres is how we’ll first study exoplanetary life, assuming it exists. The tools for characterizing atmospheres have already developed to the point that we are examining the gases surrounding some ‘hot Jupiters,’ and even talking about the movement of clouds — exoplanet meteorology — on giant worlds. The hope is that TESS will find targets that we can then investigate with new space telescopes.
Congressman Divulges Unreleased Study to Win Support for Life-Hunting Mission to Jupiter's Moon Europa10 May 2018, 15:40 UTC A mission that would sample plumes of gas shooting off of Jovian moon Europa appears to remain on track for a 2022 launch, after a meeting of the Commerce, Justice, and Science (CJS) subcommittee in which Republican Congressman John Culberson shared unreleased scientific results with his colleagues. The new paper could contain findings based on data from the Galileo mission of the late 1990s.
Scientific American 10 May 2018, 12:30 UTC Astronomers' newfound ability to see the same cosmic events in light, particles and gravitational waves—a synthesis called multimessenger astronomy—gives them a fuller picture of some of the universe's most mysterious phenomena
Sky and Telescope 9 May 2018, 20:28 UTC A pair of independent studies gives new constraints on the size of neutron stars, suggesting that they are no more than 14 kilometers (8.6 miles) in radius. That's about twice the length of the Las Vegas strip. This size limit is slightly larger than previous estimates, suggesting that neutron stars might be less exotic than previously thought.
Air & Space Magazine 9 May 2018, 14:00 UTC In a new paper published in the Journal of Geophysical Research: Planets, Sean McMahon from Yale University and colleagues present a “field guide” for scientists engaged in the search for putative fossils on Mars. The authors believe the best place to look for fossils would be in mudstones rich in silica and iron-bearing clays that formed in the ancient lakes and rivers of Mars. Microbial life could also have been preserved in silica or calcite-rich hot spring deposits—although these have yet to be found on Mars—and possibly in salt rocks.