NASA's Lucy spacecraft gets up-close look of strange peanut-shaped asteroid: See images

USA Today

22-04-2025

NASA's Lucy spacecraft gets up-close look of strange peanut-shaped asteroid: See images Donaldjohanson is likely a fragment from a collision 150 million years ago, making it one of the youngest in the main asteroid belt between the orbits of Mars and Jupiter ever visited by a spacecraft.
Show Caption
Hide Caption
Whew! Asteroid risk level shifts lower overnight for Earth impact.
Asteroid 2024 YR4 had a 3.1% chance of hitting earth in 2032 according to experts, but the chances dropped to 1.5% overnight. Here's why.
A NASA spacecraft recently got an up-close look at a strange peanut-shaped space rock floating through the cosmos in the main asteroid belt.
Not to worry: Astronomers aren't interested in the small asteroid named Donaldjohanson for any danger it poses to Earth, unlike an infamous "city-killer" asteroid that briefly attracted attention earlier this year before it, too, was dismissed as a threat.
It's the shape and possible cosmic history of Donaldjohanson that instead intrigued NASA when the space agency's Lucy spacecraft recently passed the asteroid by during its own cosmic journey. The solar-powered probe conducted a flyby on April 20 of the asteroid and has begun transmitting images back to Earth, which NASA released Monday.
Astronomers believe Donaldjohanson is a fragment from a collision 150 million years ago, making it one of the youngest in the main asteroid belt between the orbits of Mars and Jupiter ever visited by a spacecraft.
Search for extraterrestrials: Could alien life thrive on K2-18b? What to know about the distant exoplanet
NASA spacecraft gets look at strangely-shaped asteroid
Discovered in 1981, Donaldjohanson is named after the American paleoanthropologist credited with the 1974 discovery of the "Lucy" pre-human ancestor fossil – the namesake of the overarching NASA mission.
The Lucy spacecraft's observations revealed the asteroid to have an elongated shape and an odd narrow neck connecting two lobes, which NASA compared to "two nested ice cream cones." The space rock – about five miles long and two miles wide at its widest point – is believed to be a contact binary, meaning it's an object formed from two smaller cosmic bodies crashing into one another.
While flying within about 600 miles of the asteroid on April 20, the Lucy spacecraft autonomously used all three of the science instruments it's equipped with to observe Donaldjohanson in both black-and-white and infrared light.
The asteroid is not fully visible in the first set of high-resolution images NASA released Monday, as the space rock is larger than Lucy's field of view. But the space agency is in the process of downlinking the remainder of Lucy's data that will give the mission operators a better idea of the asteroid's shape and size.
What is NASA's Lucy mission?
The Donaldjohanson asteroid is not a primary science target of the Lucy mission, which commenced on Oct. 16, 2021 with the launch of the solar-powered spacecraft from the Cape Canaveral Space Force Station in Florida.
The spacecraft, which measures at nearly 52 feet wide with its solar arrays unfurled, is on a 12-year-mission to explore eight space rocks known as Trojan asteroids that share an orbit with Jupiter as it goes around the sun. The Trojan asteroids are intriguing to astronomers because they are believed to be composed of raw materials left over from the formation some 4 billion years ago of our solar system's giant planets – Jupiter, Saturn, Uranus, and Neptune.
Primarily managed from NASA's Goddard Space Flight Center in Maryland, the Lucy mission is named for a fossilized skeleton of a human ancestor, which in turn was named for the Beatles song "Lucy in the Sky with Diamonds."
Though the earlier discovery was terrestrial – not cosmic – in nature, NASA believes both share a similar DNA: Expanding humanity's understanding of our origins.
Flyby was Lucy's second asteroid encounter
Donaldjohanson is one of three asteroids in the solar system's main asteroid belt that Lucy plans to flyby in addition to the Trojan asteroids it has yet to observe.
Lucy's first asteroid encounter came on Nov. 1, 2023 when it got an up close look of an asteroid named Dinkinesh, as well as its satellite, Selam. The asteroid shares its name with the name borrowed from an Ethiopian word for the Lucy fossil.
NASA officials believe that studying such space rocks in the main asteroid belt will lend an understanding of how the planets of our solar system formed.
It's also helpful to think of the flybys of Dinkinesh and Donaldjohanson as dress rehearsals, or tests, of what's yet to come: Lucy's first encounter with one of its main targets, the Jupiter Trojan asteroid named Eurybates in August 2027.
'These early images of Donaldjohanson are again showing the tremendous capabilities of the Lucy spacecraft as an engine of discovery,' Tom Statler, program scientist for the Lucy mission, said in a statement. 'The potential to really open a new window into the history of our solar system when Lucy gets to the Trojan asteroids is immense.'
Eric Lagatta covers breaking and trending news for USA TODAY. Reach him at [e-mail]