Showing posts from October, 2018

This ball of gas is racing around the black hole at our galaxy’s heart Source:   By Daniel Clery, Science Magazine. Excerpt: Earlier this year, astronomers were looking for signs that S2, the star with the closest known orbit to the supermassive black hole thought to be at the center of the Milky Way, might—as predicted by Albert Einstein—deviate from the orbital path proscribed by Newtonian gravity. But while they were watching, they spied something else: three bright infrared flares unrelated to the star ...the signs of superheated gas racing almost as close to the black hole as possible without getting sucked in—at 30% the speed of light. Observing the action so close to the galactic center, known as Sagittarius A*, is extremely challenging because it is distant, small, and shrouded in gas and dust. The team used the world’s largest optical instrument, the European Southern Observatory’s Very Large Telescope in Chile, and combined the light of its four 8.2-

NASA Retires Kepler Space Telescope, Passes Planet-Hunting Torch Source:   NASA RELEASE 18-092. Excerpt: After nine years in deep space collecting data that indicate our sky to be filled with billions of hidden planets – more planets even than stars – NASA’s Kepler space telescope has run out of fuel needed for further science operations. NASA has decided to retire the spacecraft within its current, safe orbit, away from Earth. Kepler leaves a legacy of more than 2,600 planet discoveries from outside our solar system, many of which could be promising places for life. "As NASA's first planet-hunting mission, Kepler has wildly exceeded all our expectations and paved the way for our exploration and search for life in the solar system and beyond," said Thomas Zurbuchen, associate administrator of NASA's Science Mission Directorate in Washington. ...The most recent analysis of Kepler’s discoveries concludes that 20 to 50 percent of the

Move over, Hubble: Discovery of expanding cosmos assigned to little-known Belgian astronomer-priest Source:   By Daniel Clery, Science Magazine. Excerpt: Hubble’s Law, a cornerstone of cosmology that describes the expanding universe, should now be called the Hubble-Lemaître Law, following a vote by the members of the International Astronomical Union (IAU), the same organization that revoked Pluto’s status as a planet. The change is designed to redress the historical neglect of Georges Lemaître, a Belgian astronomer and priest who in 1927 discovered the expanding universe—which also suggests a big bang. Lemaître published his ideas 2 years before U.S. astronomer Edwin Hubble described his observations that galaxies farther from the Milky Way recede faster. ...In 1927 Lemaître calculated a solution to Albert Einstein’s general relativity equations that indicated the universe could not be static but was instead expanding. He backed up that claim with a limited

Scientists Double Down on Landing Sites for Sample-Collecting Mars Rover Source:   By Leonard David, Science Magazine. Excerpt: NASA’s Mars 2020 mission could visit two locations where microbial life may once have thrived. For NASA’s Mars 2020 rover, now being assembled at the agency’s Jet Propulsion Laboratory for launch in July 2020, the stakes could not be much higher. The $2.4 billion nuclear-powered rover is the most complex piece of machinery to ever make a ballistic beeline for the Red Planet. And after it lands in February 2021, its completion of one high-profile objective—collecting rock samples for eventual transport back to Earth—would ensure the rover sets the course for future Mars exploration for decades to come. But first, mission planners have to decide where on Mars this ambitious machine should actually go....

First moon outside the solar system could be as big as Neptune Source:   By Joshua Sokol, Science Magazine. Excerpt: With help from the Hubble Space Telescope, astronomers say they have found compelling evidence for the first known moon outside the solar system. ...this first reported “exomoon” is also strange: a Neptune-size megamoon, some 8000 light-years away, that looms over a giant planet, twice as large in the sky as Earth’s moon. ...Most theoretical models of planet formation struggle to produce such a hefty satellite. However, searches are biased toward the largest moons that might be out there, because bigger things are easier to detect. ...The first hints for the exomoon came from archival data from the Kepler probe, a NASA planet-hunting spacecraft, which looks for dips in brightness caused by unseen planets transiting in front of their suns. Alex Teachey and David Kipping, both of Columbia University, found that three dips, attributed to th

Japanese spacecraft drops a third rover on asteroid Ryugu Source:   By Dennis Normile, Science Magazine. Excerpt: After successfully dropping two small hopping rovers on the surface of asteroid Ryugu last month, the Japanese spacecraft Hayabusa2 today deployed another probe with a suite of instruments that will do some serious science. Hayabusa2, which arrived at Ryugu in June after a 3.5-year journey, descended to 51 meters above the asteroid and released the Mobile Asteroid Surface Scout (MASCOT). Twenty minutes later, the asteroid’s gravity had pulled the 10-kilogram probe, 30 by 30 by 20 centimeters in size, to the surface. ...MASCOT, jointly developed by the German Aerospace Center and the French National Centre for Space Studies, carries a camera, instruments to measure day-to-night thermal changes and check for magnetism, and an infrared spectral microscope to study the mineral composition and look for any evidence the asteroid once hosted