(CNN) — When NASA’s Lucy mission flew past its first asteroid this week, its cameras captured a surprise.
The Lucy spacecraft passed close to the small asteroid Dinginesh, located in our solar system’s main asteroid belt, between the orbits of Mars and Jupiter. But what astronomers thought was an asteroid was actually a binary pair of space rocks.
Hal Levison, Lucy’s principal investigator at the Southwestern Research Institute, said Dinginesh, which means “wonderful” in the Ethiopian Amharic language, “really lived up to her name.”
“It’s fantastic,” Levison said in a statement. “When Lucy was first selected to fly, we planned to fly over seven asteroids. With Dinginesh, the two Trojan moons and now this satellite, we’ve made it 11.
Astronomers got their first hints that Dinginesh might be a pair when Lucy’s instrument suite detected changes in brightness in the weeks leading up to the spacecraft’s approach this Wednesday.
What Dinginesh Jodi can reveal
Lucy’s team believes the largest asteroid is 805 meters (half a mile) wide and the smallest space rock is 220 meters (0.15 miles) wide.
Lucy came within 425 kilometers (265 miles) of the asteroid’s surface when it approached on Wednesday afternoon.
The close approach is designed to help the Lucy spacecraft test its suite of equipment, including its Terminal Tracking System, which allows the spacecraft to automatically detect and keep track of a space rock as it flies by at speeds of up to 10,000 miles per minute. the second).
“It’s an amazing image. They indicate that the terminal’s tracking system worked as planned, even when the universe presented us with a more difficult target than we expected,” Tom Kennedy, Lockheed Martin’s guidance and navigation engineer, said in a statement. (Lockheed Martin is NASA’s partner in the Lucy mission.)
“It’s a matter of simulating, testing and practicing,” Kennedy added. “It’s quite another to see it actually happen.”
Data collected during the flyby will also provide information about smaller asteroids, comparing them with others observed by previous NASA missions.
“It’s the smallest main belt asteroid we know of that we’ve ever seen,” said Keith Knoll, Lucy Project Scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, in a statement. “The fact that there are two of them makes it even more exciting. “In some ways, these asteroids are similar to the near-Earth binary asteroids DART saw, Didymos and Dimorphos, but there are some interesting differences that we will explore.”
In September 2022, NASA’s DART mission intentionally crashed into Dimorphos, a small moon orbiting the near-Earth asteroid Didymos, to demonstrate the technology needed to alter the trajectory of a space rock.
Preparing for future overflights
Data collected during the Lucy mission flyby will return to Earth next week. The information will help the mission team prepare for the spacecraft’s future asteroid flybys, including a close encounter with another major belt asteroid called Donald Johansson in 2025.
Lucy’s main goal is to explore the previously unexplored Jupiter Trojan asteroid clusters. The Trojan asteroids, which take their name from Greek mythology, orbit the Sun in two clusters: one in front of and one behind Jupiter, the largest planet in our solar system.
Until now, scientists’ main views of the Trojans have mostly been artistic images or animations, as the space rocks are too distant to be seen in detail through telescopes. Lucy will provide the first high-resolution images of what these asteroids look like.
Lucy is scheduled to reach the Trojan asteroids in 2027. Each of Lucy’s asteroids varies in size and color.
It takes its name from the Lucy fossil, the remains of an ancient human ancestor discovered in Ethiopia in 1974. The skeleton has helped researchers reconstruct aspects of human evolution, and NASA’s Lucy team members hope its mission will achieve a similar feat in history. of our solar system.
There are about 7,000 Trojan asteroids and the largest is 257 kilometers (160 mi) in diameter. Asteroids, like fossils, represent 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 learn how the Solar System formed 4.5 billion years ago and how the planets ended up in their current locations.