Two years after its famous flyby of Pluto, NASA’s New Horizons spacecraft is zooming toward another space rock at the edge of the Solar System, and scientists now think they may know its shape. The object could resemble a rubber duck or it could be two space rocks very close together, according to new observations. The information is key to better prepare for New Horizons’ flyby of the object, which is currently scheduled for January 1st, 2019.
The small icy body is called 2014 MU69 and it orbits about 4 billion miles away from Earth. Last month, New Horizons scientists briefly spotted 2014 MU69 from a remote part of Argentina, as the rock passed in front of a background star, momentarily blocking the star’s light. The short eclipse — also known as an occultation — was seen with five different telescopes, and gave scientists a ton of new data about 2014 MU69’s size, shape, and brightness.
Up until now, the New Horizons team has only been able to track 2014 MU69 with the Hubble Space Telescope. (Since the rock is pretty dim, telescopes like Hubble can’t gather too much information on its properties.) But the recent observations suggest that the rock is no more than 20 miles long, and its shape is not round or elliptical, like most space rocks. Instead, the icy body is either shaped like a stretched football, called an “extreme prolate spheroid,” or like two rocks joined together. That creates a rubber ducky shape similar to the comet that the European Space Agency landed on two years ago.
It’s even possible that the object is, in fact, two objects — like a pair of rocks that are orbiting around each other, or are so close that they’re touching. If 2014 MU69 does turn out to be two objects, then each one is probably between nine and 12 miles in diameter, according to the New Horizons team.
2014 MU69 was first discovered in 2014 in the Kuiper Belt, the large cloud of icy bodies that orbit beyond Neptune. Since then, we’ve had very little new information about the properties of this rock. But knowing the object’s size and shape will help the New Horizons team better plan for the spacecraft’s flyby. And it will certainly make this event much more interesting.
“This new finding is simply spectacular,” Alan Stern, the principal investigator of the New Horizons mission, said in a statement. “The shape of MU69 is truly provocative, and could mean another first for New Horizons going to a binary object in the Kuiper Belt.”