NASA has launched a probe named Lucy, after the Australopithecus fossil that rewrote the story of human origins. This Lucy’s job is to check out asteroids for even more ancient traces, rewriting the story of how our planet came to be:
NASA’s Lucy mission, the agency’s first to Jupiter’s Trojan asteroids, launched at 5:34 a.m. EDT Saturday on a United Launch Alliance (ULA) Atlas V rocket from Space Launch Complex 41 at Cape Canaveral Space Force Station in Florida.
Over the next 12 years, Lucy will fly by one main-belt asteroid and seven Trojan asteroids, making it the agency’s first single spacecraft mission in history to explore so many different asteroids. Lucy will investigate these “fossils” of planetary formation up close during its journey.
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Named for the fossilized skeleton of one of our earliest known hominin ancestors, the Lucy mission will allow scientists to explore two swarms of Trojan asteroids that share an orbit around the Sun with Jupiter. Scientific evidence indicates that Trojan asteroids are remnants of the material that formed giant planets. Studying them can reveal previously unknown information about their formation and our solar system’s evolution in the same way the fossilized skeleton of Lucy revolutionized our understanding of human evolution.
“We started working on the Lucy mission concept early in 2014, so this launch has been long in the making,” said Hal Levison, Lucy principal investigator, based out of the Boulder, Colorado, branch of Southwest Research Institute (SwRI), which is headquartered in San Antonio. “It will still be several years before we get to the first Trojan asteroid, but these objects are worth the wait and all the effort because of their immense scientific value. They are like diamonds in the sky.”
Lucy’s Trojan destinations are trapped near Jupiter’s Lagrange points – gravitationally stable locations in space associated with a planet’s orbit where smaller masses can be trapped. One swarm of Trojans is ahead of the gas giant planet, and another is behind it. The asteroids in Jupiter’s Trojan swarms are as far away from Jupiter as they are from the Sun.
The spacecraft’s first Earth gravity assist in 2022 will accelerate and direct Lucy’s trajectory beyond the orbit of Mars. The spacecraft will then swing back toward Earth for another gravity assist in 2024, which will propel Lucy toward the Donaldjohanson asteroid – located within the solar system’s main asteroid belt – in 2025.
Lucy will then journey toward its first Trojan asteroid encounter in the swarm ahead of Jupiter for a 2027 arrival. After completing its first four targeted flybys, the spacecraft will travel back to Earth for a third gravity boost in 2031, which will catapult it to the trailing swarm of Trojans for a 2033 encounter.