Pluto may be long gone, but NASA’s New Horizons spacecraft is by no means finished with the outer solar system. For the second time, New Horizons has observed 1994 JR1, a 90-mile wide Kuiper Belt Object (KBO) that orbits over 3 billion miles from the sun.
The latest observations, which were made on April 7th and 8th by New Horizons’ Long Range Reconnaissance Imager and composited in the gif below, smash the spacecraft’s own record for our closest encounter with a KBO. That record was set in November, when New Horizons observed JR1 from a distance of over 170 million miles.
Here was JR1 back in November:
And here it is last month, from a distance of just 69 million miles:
The latest observations allowed the New Horizons science team to start fleshing out a portrait of the lonely space rock. We can now pinpoint the location of JR1 to within 600 miles, giving us our most precise KBO orbit to date. Having nailed down its coordinates, astronomers can rule out a theory that JR1 is some sort of Plutonian satellite. The new data also reveals that JR1 is spinning quickly, completing a full rotation about its axis once ever 5.4 hours.
“This is all part of the excitement of exploring new places and seeing things never seen before,” John Spencer, a New Horizons science team member Southwest Research Institute in Boulder said in a statement.
Indeed, these are our first tantalising glimpses of a mysterious realm whose existence astronomers only learned of a few decades ago. You can think of the Kuiper Belt as a vast cryobank, filled with primordial chunks of rock that have not been touched or transformed since the birth of the solar system. Studying the KBOs could reveal our own cosmic origin story—which is why the New Horizons mission operators back on Earth are trying to convince NASA that we ought to conduct a close flyby of yet another KBO, 2014 MU69, in 2019.
You should be crossing your fingers that the extended New Horizons mission gets green-lit. The Pluto flyby completely revolutionised our perspective on a tiny world we thought we understood. It’s hard to imagine that pulling up close to another distance ice ball won’t shatter even more preconceptions about the outer solar system.