NASA mission captures image of surprising asteroid pair

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When NASA’s Lucy mission flew by its first asteroid this week, its cameras captured a surprise.

The Lucy spacecraft zoomed close to the small asteroid Dinkenish, located in our solar system’s main asteroid belt between the orbits of Mars and Jupiter. But what astronomers thought was a single asteroid is actually a binary pair of space rocks.

Denkenesh, which means “wonderful” in the Amharic language of Ethiopia, “has really lived up to its name,” said Hal Levison, the principal investigator on Lucy at the Southwest Research Institute.

“This is fantastic,” Levison said in a statement. “When Lucy was originally selected to fly, we planned to fly by seven asteroids. With the addition of Dinkenish, two Trojan satellites, and now this satellite, we have brought the number to 11.”

Astronomers had their first hints that Dinkenish might be a binary when the Lucy instrument cluster detected changes in brightness in the weeks leading up to the spacecraft’s approach on Wednesday.

Lucy’s team believes the larger asteroid is half a mile (805 meters) across and the smaller space rock is 0.15 miles (220 meters) across.

Lucy came within 265 miles (425 kilometers) of the asteroid’s surface during its closest approach on Wednesday afternoon.

The close approach is designed to help the Lucy spacecraft test its equipment suite, including its terminal tracking system, which allows the spacecraft to autonomously locate the space rock and keep it within view while flying at 10,000 miles per hour (4.5 kilometers per second). ).

“This is a remarkable series of images. They indicate that the ultimate tracking system is working as intended, even when the universe presented us with a more difficult target than we expected,” Tom Kennedy, a guidance and navigation engineer at Lockheed Martin, said in a statement. (Lockheed) Martin is a partner with NASA on the Lucy mission.

“Simulating, testing and practicing is one thing,” Kennedy added. “It’s quite another thing to actually see it happen.”

Data collected during the flyby will also provide insight into small asteroids, providing a comparison with other asteroids observed by previous NASA missions.

“We knew this would be the smallest main belt asteroid ever seen up close,” Lucy project scientist Keith Noll of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, said in a statement. “The fact that there are two of them makes it even more exciting. In some ways these asteroids look similar to… The near-Earth binary asteroid Didymos and Demorphos observed by DARTBut there are some interesting differences that we will investigate.

In September 2022, NASA’s DART mission intentionally collided with Dimorphos, a small moon orbiting the near-Earth asteroid Didymos, to demonstrate the technology needed to change the trajectory of a space rock.

Data collected during the Lucy mission will continue to return to Earth over the next week. This information will help the mission team prepare for the spacecraft’s future asteroid flybys, including a close encounter with another main-belt asteroid called Donald Johansson in 2025.

Lucy’s main goal is to explore Jupiter’s Trojan asteroid swarms, which have not been explored before. The Trojan asteroids, which borrow their name from Greek mythology, orbit the Sun in two swarms – one preceding Jupiter, the largest planet in our solar system, and the other trailing behind it.

Until now, scientists’ main glimpses of the Trojans have been largely artistic or animated renderings, because space rocks are too far away to be seen in detail with telescopes. Lucy will provide the first high-resolution images of what these asteroids look like.

Lucy is scheduled to arrive at the Trojan asteroids in 2027. Each of the asteroids that Lucy is scheduled to fly by is different in size and color.

The mission borrows its name from Lucy fossilthe remains of an ancient human ancestor that was discovered in Ethiopia in 1974. The skeleton has helped researchers piece together aspects of human evolution, and members of NASA’s Lucy team hope their mission will accomplish a similar feat regarding the history of our solar system.

There are about 7,000 Trojan asteroids, the largest of which is 160 miles (257 kilometers) across. Asteroids are like fossils themselves: they represent the material left over from the formation of the giant planets in our solar system, including Jupiter, Saturn, Uranus, and Neptune.

The mission will help researchers go back in time to learn how the solar system formed 4.5 billion years ago, and learn how the planets ended up in their current positions.