While en route to the Jupiter Trojan asteroids, NASA’s Lucy spacecraft recently conducted a flyby of the asteroid Dinkinesh so engineers could perform engineering tests prior to the full mission kicking off in 2027. To their surprise, they observed that Dinkinesh is not alone, as it is a binary system of asteroids, meaning there are two asteroids orbiting each other, with one much smaller than Dinkinesh. While the Lucy team had suspected it was a binary asteroid from observing variances in the Dinkinesh’s brightness over time, these findings were simultaneously surprised and excited over the encounter.
“We knew this was going to be the smallest main belt asteroid ever seen up close,” said Dr. Keith Noll, who is a Lucy project scientist at NASA’s Goddard Space Flight Center. “The fact that it is two makes it even more exciting. In some ways these asteroids look similar to the near-Earth asteroid binary Didymos and Dimorphos that DART saw, but there are some really interesting differences that we will be investigating.”
The Lucy team estimates the larger asteroid is about 0.5 miles in diameter at its widest point while the smaller asteroid is about 0.15 miles in size. Despite traveling at 10,000 mph, the Lucy spacecraft was able to capture some incredible images of the binary system, which scientists and engineers are slated to spend the next week pouring over in hopes of learning more about this incredible double asteroid.
As noted, the goal of this flyby was to conduct an engineering test of the Lucy spacecraft before it arrives at the Jupiter Trojan asteroids in 2027, which are believed to be remnants of the formation and early evolution of our solar system. Upon arrival, Lucy will investigate their geology, composition, interiors, and even if they have rings or satellites of their own, much like Dinkinesh.
What new discoveries will researchers make about asteroids in the coming years and decades? Only time will tell, and this is why we science!
As always, keep doing science & keep looking up!