Showing posts from September, 2018

Cosmic conundrum: The disks of gas and dust that supposedly form planets don’t seem to have the goods Source:   By Adam Mann, Science Magazine. Excerpt: Astronomers have a problem on their hands: How can you make planets if you don’t have enough of the building blocks? A new study finds that protoplanetary disks—the envelopes of dust and gas around young stars that give rise to planets—seem to contain orders of magnitude too little material to produce the planets. “This work is telling us that we really have to rethink our planetary formation theories,” says astronomer Gijs Mulders of the University of Chicago in Illinois, who was not involved in the research. ...The brightness of radio waves emitted by dust in the disk can be used to give a reasonable estimate of its overall mass. ...In the new study, astronomers led by Carlo Manara of the European Southern Observatory in Munich, Germany, used [Atacama Large Millimeter Array (ALMA)] to compare the masses of pro

How Well Can the Webb Telescope Detect Signs of Exoplanet Life? Source:    By Lucas Joel, Eos/AGU. Excerpt: ...what NASA’s next-generation, space-based telescope will be able to do: “see the first light of the universe, watch galaxies collide, see stars and planets being born, find and study exoplanets.” ...recent research suggests that the [James Webb Space Telescope (JWST)] might have a tricky time detecting at least one telltale sign of life: oxygen in an exoplanet’s atmosphere. ... Noah Planavsky, a biogeochemist at Yale University, and a team of researchers recently found that a planet’s atmosphere with an extremely small amount of oxygen can still support life. This finding means there could be planets that have only minute oxygen levels—but that nonetheless harbor life—that would appear to be dead to JWST. ...JWST was not originally designed to scan distant planets for their oxygen concentrations. ...JWST’s oxygen-spotting prospects may be dim, but Jo

Hayabusa-2: Japan's rovers send pictures from asteroid Source:   By BBC News. Excerpt: Japan's space agency (JAXA) has made history by successfully landing two robotic explorers on the surface of an asteroid. The two small "rovers", which were despatched from the Hayabusa-2 spacecraft on Friday, will move around the 1km-wide space rock known as Ryugu. The asteroid's low gravity means they can hop across it, capturing temperatures and images of the surface. ...Hayabusa-2 reached the asteroid Ryugu in June this year after a three-and-a-half-year journey. ...Early on Thursday morning (GMT), Hayabusa-2 began descending towards the surface of Ryugu, preparing to eject its rovers. ...The 1kg rovers are equipped with wide-angle and stereo cameras to send back pictures. Spine-like projections from the edges of the hoppers are sensors that will measure surface temperatures on the asteroid. ...The diamond-shaped asteroid has a blackish-coloured surface, and rotates on its a

NASA’s TESS Starts Collecting Planets Source:   By Dennis Overbye, The New York Times. Excerpt: The satellite, launched in April, has already identified at least 73 stars that may harbor exoplanets, most of them new to astronomers. ...They all need to be confirmed by other astronomers....