In April, New Horizons spied 1994 JR1, a 90-mile-wide object orbiting 3 billion miles from the sun. New Horizons first detected the object in November, when the spacecraft was 170 million miles away from it. When it came within 69 million miles of the small Kuiper Belt Object (KBO) on April 7 and 8, it was able to snap a picture, marking the first scientific findings of its post-Pluto career.
The images allowed scientists to pinpoint JR1's location with an accuracy unprecedented for such a small KBO, which means they'll be able to figure out its orbit. They've already used the data to determine that JR1 is not a satellite of Pluto, a theory that was floated a few years ago when the tiny world was discovered. They've also used the images to determine how quickly the planetoid rotates. By tracking the way it reflects sunlight over time, they calculated a rotation period (in other words, a day) of just 5.4 hours – which is faster than most of the KBOs that have been observed in the past.
“This is all part of the excitement of exploring new places and seeing things never seen before," New Horizons team member John Spencer said in a statement.
The photos also feature a delightful Easter egg for true New Horizons fans: That ghostly shape in the upper left corner is New Horizons herself. A very bright star just outside of the camera's field of view caused an internal camera reflection, and the result is an unexpected robot selfie – it shows the three arms that hold up the second mirror of the spacecraft's imaging system.
For now, this object is the closest thing New Horizons has observed outside the Pluto system. But the spacecraft is expected to encounter another 20 or so objects worth examining en route to its new target. Scientists are interested in KBOs because their chilly, distant neighborhood is basically a cosmic refrigerator, keeping objects largely unchanged from their state at birth (which was probably soon after the solar system formed). Studying these bodies and the materials in them could help scientists understand what the creation of the solar system was like, which could tell us something about how life evolved here – and how easy it would be for life to evolve somewhere else.
New Horizons has already been maneuvered into a course toward its new target. One way or another, it's going to come very close to a strange little world called 2014 MU69 on Jan. 1, 2019. With any luck – and with some funding for the extended mission, which has yet to be officially approved – the New Horizons team will be able to listen and learn from the spacecraft's observations.