New Horizons will soon solve a mystery about an object a billion miles past Pluto

Two for the price of one.
MU69 as two objects
But, MU69 might instead be two objects located in close proximity to each other. NASA/JHUAPL/SwRI/Alex Parker
MU69 as one object
The object, MU69, could be a single, long target. NASA/JHUAPL/SwRI/Alex Parker

In less than two years, the New Horizons space probe is going to go whizzing by an object a billion miles further away from us than Pluto at speeds of up to 30,000 miles per hour. We know generally where that object—MU69, a cold dark object in the Kuiper Belt—will be thanks to telescope observations, otherwise we wouldn’t be able to rendezvous with it at all, but like a blind date, we’re not 100 percent sure what to expect. Details like the shape, exact size, color of the object and even if it has close neighbors all remain elusive.

Last month, NASA researchers got a tantalizing glimpse of their next big destination when it passed between telescopes on Earth and the light of a distant star. But it has taken time to resolve that data into clues.

Now, NASA has released two new illustrations of what MU69 might look like based on that data. They think that overall the object is likely about 20 miles long, but its observed shape raises even more questions.

The data indicates that if MU69 is a single object, it’s probably long and oval, like a stretched football or a plump baguette with a big bite taken out of it. However, there’s a chance it’s actually two objects traveling through the void of space together—maybe even close enough to touch.

It’s not a total surprise for planetary scientists that they might be seeing double. Some estimates put contact binaries—a system with two objects touching each other—at occurring in 10 percent to 30 percent of Kuiper Belt objects.

“This new finding is simply spectacular. The shape of MU69 is truly provocative, and could mean another first for New Horizons going to a binary object in the Kuiper Belt,” Alan Stern, principal investigator of New Horizons said in a statement. “I could not be happier with the occultation results, which promise a scientific bonanza for the flyby.”

New Horizon’s will pass MU69 on January 1, 2019. Researchers will continue to gather more information from ground- and space-based telescopes in advance of the brisk drive by, when the spacecraft will switch on its cameras and instruments and snap pictures of the frozen, distant object(s) and send all that information back to Earth, a postcard from a blind date at the edges of our Solar System.