What superficially resembles a giant moth floating in space is giving astronomers new insight into the formation and evolution of planetary systems.
This is not your typical flying insect. It has a wingspan of about 22 billion miles. The wing- like structure is actually a dust disk encircling the nearby, young star HD 61005, dubbed "The Moth." Its shape is produced by starlight scattering off dust.
Dust disks around roughly 100-million-year-old stars like HD 61005 are typically flat, pancake-shaped structures where planets can form. But images taken with NASA's Hubble Space Telescope of "The Moth" are showing that some disks sport surprising shapes.
"It is completely unexpected to find a dust disk with this unusual shape," said senior research scientist Dean Hines of the Space Science Institute, New Mexico Office in Corrales, New Mexico, and a member of the Hubble team that discovered the disk. "We think HD 61005 is plowing through a local patch of higher-density gas in the interstellar medium, causing material within HD 61005's disk to be swept behind the star. What effect this might have on the disk, and any planets forming within it, is unknown."
Hines called this possible collision "unusual, because we don't expect very much interstellar material to be in the solar neighborhood. That's because the area through which our Sun is moving was evacuated within the past few million years by at least one supernova, the explosion of a massive star. Yet, here's evidence of dense material that's very close, only 100 light-years away."