Observations from NASA’s Wide-Field Infrared Survey Explorer (WISE) suggest that most Centaurs – small celestial bodies orbiting between Jupiter and Neptune – are comets rather than asteroids, said PSI Research Scientist Tommy Grav.
Centaurs, named after the mythical human-horse creatures because of their dual comet-asteroid nature, are comets traveling in towards the Sun rather than asteroids flung out from the inner solar system, according to a new paper “Centaurs and Scattered Disk Objects in the Thermal Infrared: Analysis of WISE/NEOWISE Observations” on which Grav is a co-author.
NEOWISE can tell whether the Centaurs are matte and dark like charcoal, or shiny, reflecting more light as is the case with our Moon. A better understanding of Centaurs was gained by combining this information with what is already known about their colors, Grav. Roughly two-thirds of Centaurs are likely comets hailing from the frigid outer reaches of the Solar System, the paper states. The origin of the remaining Centaurs is still unknown.
