NASA Spacecraft Unlocks Asteroid Dinkinesh's History
2024-06-04
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1NASA's Lucy spacecraft visited a little asteroid called Dinkinesh last November.
2The visit, scientists say, unlocks a surprisingly interesting history of the asteroid along with its companion, Selam.
3Asteroids are ancient objects from the beginning of the solar system.
4They offer clues about how Earth and other planets formed about 4.5 billion years ago.
5The U.S. space agency launched Lucy in 2021 on a 12-year mission to study asteroids.
6The mission is especially interested in Jupiter's Trojan asteroids, two groups of space rocks that lead and follow the giant planet as it orbits the sun.
7On the way, Lucy flew past Dinkinesh and Selam in the inner edge of the main asteroid belt.
8The spacecraft observed ridges, trough structures and other features on Dinkinesh.
9Dinkinesh has a diameter of nearly 720 meters. Selam is made up of two similarly sized lobes, one about 230 meters wide and the other about 210 meters.
10Selam orbits Dinkinesh once about every 53 hours at a distance of about 3.1 kilometers.
11It appears, the researchers said, that a big piece of rock broke free sometime in the past from Dinkinesh.
12The rock was about a quarter its total size, creating a trough on its surface and sending debris into space.
13Some of this debris, they said, fell back onto Dinkinesh's surface to form a ridge structure.
14Other materials came together to form Selam, becoming what is called a contact-binary moonlet.
15Katherine Kretke, from the Southwest Research Institute in Colorado, is a co-writer of the study published in Nature.
16She said that "a contact-binary is when it appears that a single body is composed of two objects that collided gently enough not to become disrupted."
17Kretke said they are common in the solar system, but Selam was "the first time a contact-binary has been observed orbiting another asteroid."
18Simone Marchi is another co-writer of the study.
19He said, "A planet like Earth formed by the accumulation of countless small bodies. Understanding the properties of small asteroids such as Dinkinesh and Selam helps us to have a better picture of the earliest phases of planet formation."
20NASA's spacecraft was named for the Ethiopian fossil of the extinct human relative Australopithecus called "Lucy."
21That fossil has provided information about early human beings, much like asteroids provide knowledge of planetary formation.
22Dinkinesh is the Ethiopian name for the Lucy fossil, meaning "you are marvelous" in the Amharic language.
23Selam, the Ethiopian name for another Australopithecus fossil, means "peace" in Amharic.
24Lucy will next visit the asteroid Donaldjohanson in 2025 in the main asteroid belt.
25The spacecraft is expected to visit 11 asteroids in total.
26I'm Dan Novak.
1NASA's Lucy spacecraft visited a little asteroid called Dinkinesh last November. The visit, scientists say, unlocks a surprisingly interesting history of the asteroid along with its companion, Selam. 2Asteroids are ancient objects from the beginning of the solar system. They offer clues about how Earth and other planets formed about 4.5 billion years ago. 3The U.S. space agency launched Lucy in 2021 on a 12-year mission to study asteroids. The mission is especially interested in Jupiter's Trojan asteroids, two groups of space rocks that lead and follow the giant planet as it orbits the sun. 4On the way, Lucy flew past Dinkinesh and Selam in the inner edge of the main asteroid belt. The spacecraft observed ridges, trough structures and other features on Dinkinesh. 5Dinkinesh has a diameter of nearly 720 meters. Selam is made up of two similarly sized lobes, one about 230 meters wide and the other about 210 meters. Selam orbits Dinkinesh once about every 53 hours at a distance of about 3.1 kilometers. 6It appears, the researchers said, that a big piece of rock broke free sometime in the past from Dinkinesh. The rock was about a quarter its total size, creating a trough on its surface and sending debris into space. Some of this debris, they said, fell back onto Dinkinesh's surface to form a ridge structure. 7Other materials came together to form Selam, becoming what is called a contact-binary moonlet. 8Katherine Kretke, from the Southwest Research Institute in Colorado, is a co-writer of the study published in Nature. She said that "a contact-binary is when it appears that a single body is composed of two objects that collided gently enough not to become disrupted." 9Kretke said they are common in the solar system, but Selam was "the first time a contact-binary has been observed orbiting another asteroid." 10Simone Marchi is another co-writer of the study. He said, "A planet like Earth formed by the accumulation of countless small bodies. Understanding the properties of small asteroids such as Dinkinesh and Selam helps us to have a better picture of the earliest phases of planet formation." 11NASA's spacecraft was named for the Ethiopian fossil of the extinct human relative Australopithecus called "Lucy." That fossil has provided information about early human beings, much like asteroids provide knowledge of planetary formation. 12Dinkinesh is the Ethiopian name for the Lucy fossil, meaning "you are marvelous" in the Amharic language. Selam, the Ethiopian name for another Australopithecus fossil, means "peace" in Amharic. 13Lucy will next visit the asteroid Donaldjohanson in 2025 in the main asteroid belt. The spacecraft is expected to visit 11 asteroids in total. 14I'm Dan Novak. 15Dan Novak adapted this story for VOA Learning English based on reporting by Reuters. 16____________________________________________ 17Words in This Story 18belt - n. a band of material that is worn around a person's waist 19ridge - n. a long area of land that is on top of a mountain or hill 20trough - n. a long, low area between waves or hills 21lobe - n. a curved or rounded part of something 22debris - n. the pieces that are left after something has been destroyed 23collide - v. to hit something or each other with strong force 24accumulate - v. to gather or acquire gradually as time passes 25fossil - n. something that is from a plant or animal which lived in ancient times and that you can see in some rocks 26marvelous - adj. extremely good or enjoyable