In 1974, paleoanthropologist Donald Johanson and his team discovered dozens of fossilized bones in Ethiopia’s Awash Valley. Together, they made up 40% of the skeleton of a female Australopithecus afarensis, a 3.2 million year old hominin that was just over 3 feet tall.
The official name of the skeleton is AL 288-1. But the night after her recovery, Johanson played “Lucy in the Sky with Diamonds” by The Beatles from his little Sony tape recorder at the dig. The next morning at breakfast it was clear: The skeleton would be called Lucy, Scientific American reported in 2014.
Since its discovery 47 years ago, Lucy (and the early hominin fossils that archaeologists later discovered) has transformed scientists’ understanding of human evolution. Now a new Lucy is to shed light on the history of our entire solar system – and perhaps our place in it.
NASA’s Lucy, the very first mission to study a series of mysterious asteroids orbiting the Sun along with Jupiter, will start tomorrow (Saturday, October 16). The mission is named after the Lucy fossil because the asteroids it will visit are “fossils of planet formation,” said Lucy project manager Donna Douglas-Bradshaw in a NASA interview. These asteroids, called Trojan asteroids, orbit the Sun near Jupiter. They are believed to be “mere remnants of our solar system formation,” said Douglas-Bradshaw.
Cory Prykull, who heads Lucy assembly, test and launch operations at Lockheed Martin Space, joked that asteroids, which are space rocks made of silica and metals, can seem “relatively boring”. But as “planetary fossils,” they also contain “all kinds of stories about where they came from, how they were formed, and what materials are actually in these different parts of the solar system,” he said in a NASA interview. At around 4 billion years old, the Trojan asteroids are among the oldest fossils in our solar neighborhood. And, explained Prykull, “represent the fragments left over from the formation of the outer planets”.
So far, astronomers have only viewed the Trojans from a distance with large telescopes and other observation devices here on Earth. This equipment, while impressive, only provides “really grainy images” of the asteroids, said Prykull: “We’re very excited to visit as we don’t know exactly what’s out there.”
With Lucy, astronomers hope to get high-resolution images and “some vital insight into what materials are in these Trojan asteroids,” said Prykull. A better understanding of these materials could help researchers find out what building blocks were available during the formation of our solar system. “What we really want to find out, said Prykull, is what things were available to create these outer planets. And that will enormously expand our knowledge and understanding of how our planets were formed and, consequently, how we as a cosmic and solar system neighborhood really became our own. “
Lucy’s 12-year mission, which will span a total of 4 billion miles, begins with a year-long Earth orbit. Next up is an Earth Gravity Assistant, a flyby technique that will “pump our energy and trajectory” to the asteroids, Douglas-Bradshaw said. “You can think of the earth as a slingshot,” she added.
Lucy will first launch the “L4 swarm” of Trojan asteroids in a region off Jupiter’s orbit. Then the spaceship returns to earth, hurls over another gravity aid and goes to the remaining Trojans.
Prykull, who has worked on the Lucy mission since the first pieces “hit production,” is most looking forward to tomorrow’s launch, he said, “and [when] Our space probe has fully installed solar panels and is nominally healthy in space and ready to begin its journey. “
Curious about Lucy Mission Updates? Check out NASA’s Lucy Mission Resources page and follow her social media accounts at @NASA.
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