In early November, something lucky happened. It had to do with NASA's Lucy mission, a solar-winged probe that is currently on its way to look into a group of old rocks that are stuck in Jupiter's orbit around the sun. They are known as the Trojans, and some think they are extra pieces from the box that made our solar system.
But now we're not going to talk about the powerful Trojans. This is about a small space rock called Selam.
This is Selam's story.
In the early hours of November 1, Lucy flew by one of its non-Trojan targets. These are like small steps (stepping rocks) on the mission's bigger path. Its name is Dinkinesh, or as scientists cutely call it, "Dinky." But soon after, on November 2, the Lucy team told everyone about a surprise. The number Dinkinesh is not just one, but two asteroids working together! To put it another way, Dinky had its own moon. It made the scientists very happy. They had no idea that Dinky was going to surprise us again.
Everyone was shocked when, on November 7, the team said that Dinky's newfound satellite had another newfound satellite. The team said that the first satellite was a "contact-binary," which means that it was made up of two things that were touching each other: a moon and a meta-moon. This was the first time that a contact pair circling an asteroid was found.
The main scientist for Lucy at the South-west Research Institute, Hal Levison, said in a statement at the time, "It is, to say the least, puzzling." "This system looks like something I never thought I'd see. In particular, I don't get why the two parts of the satellite are about the same size. Scientists will have a good time figuring this out.
That was all that was left? Something to call it.
And on November 29, the Lucy team announced that we now have a name for Dinky's little friend who is neither male nor female: Selam.
Raphael Marshall of the Observatoire de la Côte d'Azur in France said in a statement, "Dinkinesh is the Ethiopian name for the fossil known as 'Lucy.'" Marshall had found Dinkinesh as a possible target for the Lucy mission. "It seemed appropriate to name its satellite in honour of another fossil that is sometimes called Lucy's baby."
NASA says that Zeresenay Alemseged found the fossil Selam in Dikika, Ethiopia, in the year 2000. The Natural History Museum says it is thought to have belonged to a 3-year-old girl of the same species as Lucy. It was one of the first human remains to become well-known. Selam, on the other hand, may have lived more than 100,000 years before Lucy. Wonderfully, Selam means "peace" in the Amharic language of Ethiopia, and Dinkinesh means "you are wonderful."
At the time that its moon was found, Levison said, "Dinkinesh really lived up to its name; this is wonderful."
The team now plans to look into Dinkinesh and Selam in more depth to find out how this asteroid-ception started in the first place. There's probably a good amount of data to go on thanks to Lucy's onboard tools, like the high-resolution L'LORRI camera and Terminal Tracking Cameras.
Amy Simon of NASA's Goddard Space Flight Centre in Greenbelt, Maryland, said, "To put together the final images, we have to carefully account for the spacecraft's motion. Lucy's accurate pointing information makes this possible." "These pictures will help scientists figure out what the asteroids are made of. They will let the team compare the Dinkinesh and Selam's make-up and figure out how these bodies may be made of the same stuff as other asteroids."
Lucy has been travelling through space since 2021, and its first stop on a space rock has already produced such interesting results. One can only imagine what the rest of its 12-year journey will bring.