Though nearly 2,000 planets have been found around other stars, the light from only a handful of them has ever been collected by the world's most powerful telescopes. Ironically, a lot of them are detected by the shadows they cast, as they pass in front of their parent stars. Follow-up observations measure the planet's feeble, but telltale, gravitational tug on its parent star. Now, Hubble Space Telescope astronomers have been able to pick up the faint infrared glow of a giant planet located 170 light-years away from Earth. Not only is it glowing, but also rhythmically flickering as the planet spins on its axis like a top. The interpretation is that the subtle changes in the planet's brightness are due to a variegated cloud cover of comparatively bright and dark patches coming and going. These measurements have led to an estimate of how fast the planet is spinning through direct observation a first for exoplanet astronomers. The gaseous world completes one rotation approximately every 10 hours, which, coincidentally, is the same rotation rate as Jupiter.
After years of preparatory studies, NASA is formally starting an astrophysics mission designed to help unlock the secrets of the universe the Wide-Field Infrared Survey Telescope (WFIRST). WFIRST will image large regions of the sky in near-infrared light to answer fundamental questions about dark energy and the structure and evolution of the universe. It will also find and characterize planets beyond our solar system, and as a general-purpose observatory, revolutionize many other astrophysical topics. WFIRST will have a mirror the same size as Hubble's, but it will have a 100 times wider view of space. Slated for launch in the mid-2020s, it will complement the capabilities of NASA's other major astrophysical observatories.
On February 17 at 5:45pm JST this H-IIA rocket blasted skyward from JAXA's Tanegashima Space Center located off the southern coast of Japan, planet Earth. Onboard was the ASTRO-H X-ray astronomy satellite, now in orbit. Designed to explore the extreme cosmos from black holes to massive galaxy clusters, the satellite observatory is equipped with four cutting-edge X-ray telescopes and instruments sensitive to photon energies from 300 to 600,000 electron volts. By comparison, visible light photon energies are 2 to 3 electron volts. Following a tradition of renaming satellites after their successful launch, ASTRO-H has been newly dubbed "Hitomi", inspired by an ancient legend of dragons. Hitomi means "the pupil of the eye".
Water has left its mark in a variety of ways in this martian scene captured by ESA’s Mars Express.
