NASA Finds That One Supernova Could Produce 7,000 Earths
In spite of its name, stardust doesn't just compose stars; rather, it plays a hand in forming all celestial bodies, including planets such as Earth. Now, a new NASA study shows that supernovae, or the explosions of dying stars, may produce the lion's share of the stardust that ultimately forms planets and other celestial objects.
For the study, NASA's Stratospheric Observatory for Infrared Astronomy (SOFIA), an airborne observatory that makes infrared observations, captured infrared images of a cloud of interstellar dust called Supernova Remnant Sagittarius A East. Then, judging from the intensity of the cloud's radiation emissions, SOFIA estimated the total mass of the interstellar dust.
"Our observations reveal a particular cloud produced by a supernova explosion 10,000 years ago contains enough dust to make 7,000 Earths," said Ryan Lau of Cornell University in a NASA statement.
'SOFIA data reveal warm dust (white) surviving inside a supernova remnant. The SNR Sgr A East cloud is traced in X-rays (blue). Radio emission (red) shows expanding shock waves colliding with surrounding interstellar clouds (green).'
Previous studies had indicated that supernovae could release a large amount of interstellar dust, enough to populate galaxies with celestial bodies. But until now, it was unknown whether that dust released during the explosion would survive the subsequent shock waves.
"The dust survived the later onslaught of shock waves from the supernova explosion, and is now flowing into the interstellar medium where it can become part of the 'seed material' for new stars and planets," said Lau.
'Supernova remnant dust detected by SOFIA (yellow) survives away from the hottest X-ray gas (purple). The red ellipse outlines the supernova shock wave. The inset shows a magnified image of the dust (orange) and gas emission (cyan).'
NASA's results, in addition to shedding further light on the formation of the objects in our galaxy, may also explain the interstellar dust clouds observed in distant galaxies. The interstellar dust clouds in certain young galaxies are so large that no phenomenon aside from a supernova could possibly release enough dust.
"This discovery... demonstrat[es] how observations made within our own Milky Way galaxy can bear directly on our understanding of the evolution of galaxies billions of light years away," said SOFIA project scientist Pamela Marcum.