A new study from researchers at the University of Hawaii suggests that the C/2014 S3 (PANSTARRS) comet was created in the inner solar system at the same time as Earth before being ejected. The results reveal that the comet has ancient origins and was eventually preserved in the low temperatures of the Oort Cloud for billions of years.
"We already knew of many asteroids, but they have all been baked by billions of years near the Sun," said Karen Meech of the University of Hawaii and lead author of the study. "This one is the first uncooked asteroid we could observe: it has been preserved in the best freezer there is."
C/2014 S3 possesses a long orbital period of approximately 860 years and was originally deemed a weakly active comet. Now, scientists believe that after originating in the Oort Cloud, it was recently pushed into an orbit closer to the sun.
The researchers noticed that C/2014 S3 lacks the tail that is observed in typical long-period comets that come into close proximity of the sun, prompting them to name it a Manx comet after the tailless cat. Using the European Space Agency's (ESO) Very Large Telescope, the team gathered spectra of the faint object.
The study reveals that the light reflected by the unique comet mirrors that of S-type asteroids that are commonly found in the inner asteroid main belt. Its rocky characteristics conflict with the common icy characteristics of comets that stem from the outer solar system.
C/2014 S3 is composed of material that suggests a long deep freeze, and its weak comet-like activity - typically associated with the sublimation of water ice - is a million times lower than that observed in active long-period comets that are an equal distance from the sun.
The results suggest that C/2014 S3 is composed of recent inner solar system material that originates from the Oort Cloud and is only now travelling back into the inner solar system.
"We've found the first rocky comet, and we are looking for others," said Olivier Hainaut from the ESO and co-author of the study. "Depending on how many we find, we will know whether the giant planets danced across the solar system when they were young, or if they grew up quietly without moving much."
The findings were published in the April 29 issue of the journal Science Advances.
