The target=”_self”>space agency’s Lucy mission is en route to the never-explored Trojan asteroids — trapped in swarms around Jupiter and thought to be pristinely-preserved building blocks of planets — and just zoomed by its first target. It’s an asteroid that mission planners wanted to visit before reaching the Trojans, to test the spacecraft’s crucial abilities to track these distant objects at blazing speeds of 10,000 mph.
It turns out this target, Dinkinesh, is two asteroids: a smaller asteroid orbiting a bigger asteroid.
“This is an awesome series of images,” Tom Kennedy, a mission guidance and navigation engineer at Lockheed Martin, said in a statement. “They indicate that the terminal tracking system worked as intended, even when the universe presented us with a more difficult target than we expected.”
You can see these two rocky asteroids, called an “asteroid binary,” in the images below. The bigger one is about a half-mile wide (790 meters across), and the smaller some 0.15 miles (220 meters).
Credit: NASA / Goddard / SwRI / Johns Hopkins APL / NOAO
The Lucy mission, named after the ancient remains of the famous fossilized human skeleton, will loop through the solar system, without slowing down, to investigate the Trojan asteroids. They’re like “fossils” from our solar system’s formation from some 4 billion years ago; the untarnished Trojans are the type of smaller rocky and icy objects that would have contributed to making planets.
Each encounter will speed by at around 10,000 mph.
“We’re not going to be able to blink,” Hal Levison, a planetary scientist who leads the unprecedented mission to investigate the Trojans, told Mashable last year.
“If we want to understand ourselves, we have to understand these small bodies.”
During each encounter, Lucy’s powerful cameras, including a spectrometer that can see what the asteroids are composed of, will observe the rocks’ composition, mass, and geologic history. They’ll see how icy the Trojans are, and how different they are from each other. Planetary scientists already know some are dark red and resemble some of the extremely distant objects found today in the outskirts of the solar system, beyond Neptune.
“If we want to understand ourselves, we have to understand these small bodies,” Levison said.
The Lucy spacecraft’s next asteroid encounter happens in 2025, as it speeds by the space rock Donaldjohanson. The mission will reach the first of a half-dozen Trojans in 2027.