This afternoon, scientists on NASA’s New Horizons mission shared the first close-up images of the distant, frozen space rock their spacecraft whizzed by on New Year’s Day. The pictures bring the strange object into a clearer focus — and it looks like a lumpy snowman. In fact, it’s not really one object, but two lobes that are touching each other, what’s known as a contact binary.
The images were taken on January 1st around 12:33AM ET, when the New Horizons spacecraft sped past the rock at a whopping 32,000 miles per hour. The vehicle, which came within 2,200 miles of the object’s surface, used all seven of its onboard instruments to gather as much data as it could about the rock during the flyby. Those instruments included two cameras that were used to create the image above.
Though the pictures were snapped in the wee hours of January 1st, it took a while for the mission team to see them. That’s because New Horizons is currently 4.1 billion miles from Earth, and one radio signal takes about six hours to reach our planet. After New Horizons had collected all the information it could about the object, it then sent a signal back to Earth confirming it was in good health and that everything had gone as expected. That signal was received at 10:30AM ET. After that, it started sending over the juicy image.
These pictures are the first high-resolution ones we have of an object in the Kuiper Belt other than Pluto and its moons. The Kuiper Belt is a giant region beyond the path of Neptune, where potentially millions of tiny, frozen objects orbit around the Sun. In fact, these objects are so cold and so tiny that they’re thought to be essentially frozen in time, preserved from the early days of the Solar System. That means studying these materials could tell us a lot about what materials were lurking around when the planets were coming into being.
Before today, the only pictures we had of this object — named 2014 MU69 — were fuzzy, just a few pixels across. At 21 miles wide, the rock was hard to track from a distance and it is incredibly faint, making it hard to see. But now that New Horizons has flown by, the spacecraft has a wealth of data about the rock, which could tell us more about what it’s made of and how it came to be.
The New Horizons team believe that MU69 may have formed during the early Solar System, and that it got its start as two separate objects within a rotating cloud of debris. Eventually, this rotation brought the two lobes of the rock together, while other debris in the cloud were ejected outward. The rocks probably connected very slowly, moving at about the same speed one would park a car. Then, it’s possible that fine material collected around the contact point, creating that bright band that can be seen in the photos.
There’s still a lot we don’t know about this object, but more answers are coming. During the flyby, New Horizons collected about 50 gigabits of data — about the capacity of a small flash drive — which the spacecraft will transmit very slowly back to Earth. The slow speed of transmission, combined with the six-hour transit time for radio signals, means we have nearly two years of data downloads. And that means we’ll get even better pictures of MU69 in the days and months ahead.
New Horizons went through the same process when it conducted its first, more famous flyby in 2015. That summer, the probe became the first vehicle to fly by the dwarf planet Pluto, also providing high-resolution images of that distant world.