Thursday, 30 May 2024

'Dinky' asteroid imaged by NASA has ultra-rare double moon, study confirms

 

Image courtecy of NASA/Goddard/SwRI/Johns Hopkins APL/NOIRLab

Joel Kontinen 

Researchers have proposed a model for how a double moon named Selam formed around the tiny asteroid Dinkinesh. This is the first 'contact binary' moon ever discovered, scientists say.

“When NASA's Lucy mission flew past the asteroid Dinkinesh on Nov. 1, 2023, it discovered an unexpected companion: a pair of fused moons that scientists named Selam. Now, researchers have proposed a model explaining how Selam may have formed.”

It seems that space is more wonderful than we thought.

Astronomers supervising Lucy ― a car-sized spacecraft that launched on Oct. 16, 2021 ― had primarily intended to study Jupiter's Trojan asteroids, two swarms of space rocks that lead and lag behind the gas giant as it careens around the sun. However, in January 2023, they added the diminutive main-belt asteroid Dinkinesh — affectionately called "Dinky" — to the spacecraft's travel itinerary as its first destination. This flyby was supposed to be a dress rehearsal, allowing Lucy's team to test a system for tracking and imaging asteroids.

As Lucy approached Dinky, astronomers saw signs that the small asteroid was orbited by an even smaller moon. But when Lucy swooshed past — ultimately coming within 430 kilometres or 267 miles of the asteroid while snapping hundreds of high-definition photos — the researchers saw the truth was even stranger than they predicted. The images revealed that Selam wasn't one, but two "moonlets" touching each other as they orbited Dinkinesh. “

Source:

 Deepa Jain 2024 'Dinky' asteroid imaged by NASA has ultra-rare double moon, study confirms | Live Science 30 May.