Star mapper provides Milky Way portrait
The European Space Agency’s Gaia satellite has now mapped almost 2 billion of the Milky Way’s stars, logging their positions, speeds, temperatures, and other parameters—and allowing astronomers to chart the Galaxy’s structure and evolution. Last week, operators released the third major trove of data, including lists of 800,000 binary stars, 10 million variable stars, and, within the Solar System, 156,000 asteroids and rocky bodies. Launched in 2013, Gaia has already uncovered new nearby satellite galaxies, fast-moving stars escaping the Milky Way, and evidence of past galaxies that merged with ours. The new data show thousands of stars are convulsed by giant, violent waves. And, for the first time, the data also include spectra—breakdowns of starlight—that point to chemical compositions. Stars forge heavier elements and disperse them when they explode; the elements are taken up by subsequent generations of stars. Mapping that information shows the abundance of heavy elements is highest in the Galaxy’s central disk, where stars live fast and die young.
Dust grain hits Webb space telescope
One mirror segment of NASA’s James Webb Space Telescope was struck by a micrometeoroid last month, leading to a “marginally detectable effect” on its data collection, the agency said last week. Launched nearly 6 months ago, Webb has a 6.5-meter, gold-coated mirror made of 18 hexagonal segments. Mission planners expected many specks of high-speed space dust to ding Webb during its lifetime and simulated their impact using spare mirror segments. Operators recorded four small strikes during Webb’s deployment and commissioning phase. NASA estimated the speck that struck it in May was larger, but less than 0.1 millimeter wide. The telescope is designed to withstand many such hits, and engineers have already adjusted the shape and position of the affected mirror segment to mitigate distortion from the damage; NASA says the telescope’s performance still exceeds all mission requirements.
U.S. nixes funding Russia work
The U.S. government last week said it will not fund new collaborations with research institutions affiliated with Russia’s government and individuals working at those institutions, in response to Russia’s 24 February invasion of Ukraine. The 11 June announcement comes months after several European nations went further, freezing existing collaborations. The U.S. policy allows existing joint projects to continue until completed. Some U.S. institutions have already voluntarily canceled existing collaborations with Russian universities; for example, in February the Massachusetts Institute of Technology pulled out of one with the Skolkovo Institute of Science and Technology, which MIT had helped found.