A forming exoplanet could make moons

摘要

New telescope images may provide the first view of moons forming outside the solar system.The Atacama Large Millimeter/ submillimeter Array, or ALMA, in Chile glimpsed a dusty disk of potentially moon-forming material around a baby exoplanet about 370 light-years from Earth. The Jupiter-like world is surrounded by enough material to make up to 2.5 Earth moons, researchers report in the July 20 Astrophysical Journal Letters.ALMA observed a planet dubbed PDS 70c circling the star PDS 70 (center, above) in July 2019. Unlike most known exoplanets, this world is still forming, gobbling up material from the disk of gas and dust swirling around its star. During this formation process, planets are expected to wrap themselves in their own debris disks, which control how planets pack on material and form moons.