A pair of experts has found that a well-known asteroid discovered by the Lincoln Near-Earth Asteroid Research (LINEAR) facility in New Mexico in 2000 goes through an identity crisis.
Astronomers Scott Sheppard, from the Carnegie Institution for Science and dwarf planet Eris co-discovereR Chadwick Trujillo, from the Gemini Observatory, have discovered an unexpected tail on asteroid 62412.
At the American Astronomical Society's Division for Planetary Sciences meeting in Tucson, Arizona on Tuesday, Nov. 11, the two astronomers revealed that 62412, also known as 2000 SY178, is an active asteroid.
Just like other asteroids, active asteroids have stable orbits between planets Jupiter and Mars but they are different in that sometimes, they take the appearance of comets when dust or gas is released from their surfaces producing a sporadic tail effect.
With Sheppard and Trujillo's discovery of an unexpected tail on asteroid 62412, the object which used to be known as a typical asteroid for many years, is now being reclassified as an active steroid and marks it as the first comet-like object from the Hygeia family. The astronomers' findings also make the asteroid the 13th known active main-belt asteroid of the 100 that are believed to exist.
"We report a new active asteroid in the main belt of asteroids between Mars and Jupiter. Object (62412) 2000 SY178 exhibited a tail in images collected during our survey for objects beyond the Kuiper Belt using the Dark Energy Camera (DECam) on the CTIO 4 meter telescope," the astronomers wrote.
Although the reason behind the loss of dust or gas and the subsequent tail in active asteroids remains unknown, several theories have been posited to explain the phenomenon including recent impacts or the sublimation of the exposed ices from solid to gas.
Asteroid were long believed to be mostly unchanging but with better imaging techniques that improved capabilities to observe them, scientists are now able to discover tails and comas, the atmospheric envelope the surround the nucleus of the comet. An asteroid may be similar to comets but it is often distinguished as it is because visible coma characterizes comets.
"Until about ten years ago, it was pretty obvious what a comet was and what a comet wasn't, but that is all changing as we realize that not all of these objects show activity all of the time," Sheppard said. "We're actually looking anew through our deep survey at a population of objects that other people cannot easily observe, because we're going much deeper."
