Thursday, August 25, 2016

Ariane 5 Successfully Lofts Two Communications Satellites for Intelsat

Ariane 5 rocket lifts off with two Intelsat satellites on Aug. 24. Credit: Arianespace

Thundering off the launch pad at Kourou in French Guiana, an Ariane 5 booster took to the skies on Wednesday, Aug 24, to deliver Intelsat 33e and Intelsat 36 commsats into orbit. The mission, designated VA232 in Arianespace’s numbering system, lifted off at 5:55 p.m. EDT (21:55 GMT) from the Ariane Launch Complex No. 3 (ELA 3).

Fossilised Rivers Suggest Warm, Wet Ancient Mars

Perspective view of Aram Dorsum, an inverted channel on Mars and candidate landing site for the ExoMars rover (credit: NASA/JPL/MSSS)

Extensive systems of fossilized riverbeds have been discovered on an ancient region of the Martian surface, supporting the idea that the now cold and dry Red Planet had a warm and wet climate about four billion years ago, according to UCL-led research. The study, published in Geology and funded by the Science & Technology Facilities Council and the UK Space Agency, identified over 17,000 km of former river channels on a northern plain called Arabia Terra, providing further evidence of water once flowing on Mars.

Cosmic Neighbors Inhibit Star Formation, Even in the Early-Universe

Color images of the central regions of z > 1.35 SpARCS clusters. Cluster members are marked with white squares. Credit: SpARCS collaboration.

The international University of California, Riverside-led SpARCS collaboration has discovered four of the most distant clusters of galaxies ever found, as they appeared when the universe was only 4 billion years old. Clusters are rare regions of the universe consisting of hundreds of galaxies containing trillions of stars, as well as hot gas and mysterious dark matter. Spectroscopic observations from the ground using the W. M. Keck Observatory in Hawaii and the Very Large Telescope in Chile confirmed the four candidates to be massive clusters. This sample is now providing the best measurement yet of when and how fast galaxy clusters stop forming stars in the early Universe.

Can One Cosmic Enigma Help Solve Another?

This artist's illustration depicts the merging black hole binary systems for GW150914 (left image) and GW151226 (right image). The black hole pairs are shown together in this illustration, but were actually detected at different times, and on different parts of the sky. The images have been scaled to show the difference in black hole masses. In the GW150914 event, the black holes were 29 and 36 times that of our Sun, while in GW151226, the two black holes weighed in at 14 and 8 solar masses. Image credit: LIGO/A. Simonnet.

Astrophysicists from Johns Hopkins University have proposed a clever new way of shedding light on the mysterious dark matter believed to make up most of the universe. The irony is they want to try to pin down the nature of this unexplained phenomenon by using another, an obscure cosmic emanation known as “fast radio bursts.”

Wednesday, August 24, 2016

A Surprising Blazar Connection Revealed

Black-hole-powered galaxies called blazars are the most common sources detected by NASA's Fermi Gamma-ray Space Telescope. As matter falls toward the supermassive black hole at the galaxy's center, some of it is accelerated outward at nearly the speed of light along jets pointed in opposite directions. When one of the jets happens to be aimed in the direction of Earth, as illustrated here, the galaxy appears especially bright and is classified as a blazar. Credit: M. Weiss/CfA

Astronomers studying distant galaxies powered by monster black holes have uncovered an unexpected link between two very different wavelengths of the light they emit, the mid-infrared and gamma rays. The discovery, which was accomplished by comparing data from NASA's Wide-field Infrared Survey Explorer (WISE) and Fermi Gamma-ray Space Telescope, has enabled the researchers to uncover dozens of new blazar candidates.

Test for Damp Ground at Mars' Seasonal Streaks Finds None

Blue dots on this map indicate sites of recurring slope lineae (RSL) in part of the Valles Marineris canyon network on Mars. RSL are seasonal dark streaks that may be indicators of liquid water. The area mapped here has the highest density of known RSL on Mars. Credits: NASA/JPL-Caltech/Univ. of Arizona

Seasonal dark streaks on Mars that have become one of the hottest topics in interplanetary research don't hold much water, according to the latest findings from a NASA spacecraft orbiting Mars. The new results from NASA's Mars Odyssey mission rely on ground temperature, measured by infrared imaging using the spacecraft's Thermal Emission Imaging System (THEMIS).

Planet Found in Habitable Zone Around Nearest Star

This artist’s impression shows a view of the surface of the planet Proxima b orbiting the red dwarf star Proxima Centauri, the closest star to the Solar System. The double star Alpha Centauri AB also appears in the image to the upper-right of Proxima itself. Proxima b is a little more massive than the Earth and orbits in the habitable zone around Proxima Centauri, where the temperature is suitable for liquid water to exist on its surface.  Credit: ESO/M. Kornmesser

Astronomers using ESO telescopes and other facilities have found clear evidence of a planet orbiting the closest star to Earth, Proxima Centauri. The long-sought world, designated Proxima b, orbits its cool red parent star every 11 days and has a temperature suitable for liquid water to exist on its surface. This rocky world is a little more massive than the Earth and is the closest exoplanet to us — and it may also be the closest possible abode for life outside the Solar System. A paper describing this milestone finding will be published in the journal Nature on 25 August 2016.