ook! Up in the sky! It's a comet... It's an asteroid... Actually, what the hell is it? A mysterious object will be flying past Earth next month. However, its characteristics are so unusual that even the brightest brains over at NASA can't figure out what exactly it is.
The object, dubbed 2016 WF9, was spotted by NASA’s asteroid-and-comet-hunting NEOWISE project on November 27, 2016. NEOWISE scientists believe that it could be as large as 1 kilometer (0.6 mile) wide. It’s expected to make its closest approach to Earth’s orbit on February 25 at a distance of 51 million kilometers (32 million miles).
The object is causing a bit of confusion among NASA scientists, as they can’t tell if it’s a comet or an asteroid. As a general (but by no means foolproof) rule, asteroids tend to be rocky or more metallic, while comets tend be icier. This object appears to be dark and unreflective, which is typically an indication it is a comet. Despite that, it lacks the characteristic dust and gas cloud that defines a comet. This lack of clarity also means the object has an unknown origin.
“2016 WF9 could have cometary origins," Deputy Principal Investigator James "Gerbs" Bauer at NASA Jet Propulsion Laboratory said in a statement. "This object illustrates that the boundary between asteroids and comets is a blurry one; perhaps over time this object has lost the majority of the volatiles that linger on or just under its surface."
NEOWISE did, however, manage to discover another object that they understand more about. Late last year, they also found C/2016 U1, a comet that is cruising by Earth right now.
It will be viewable from the Northern Hemisphere during the first week of 2017 in the southeastern sky during the hours before sunrise. You’ll even be able to catch a glimpse of it with a good pair of binoculars, if the cloud coverage and unpredictable brightness of the comet is favorable.