NASA’s Lucy spacecraft launched in 2021 and will eventually make it to Jupiter’s Trojan asteroids where it’ll explore the rocky location for clues on how our solar system formed.
Its journey to get there is a complex one as it needs to utilize Earth’s gravity to “slingshot” it at speed for a second gravity assist around Earth in two years’ time that will set it on a course for Jupiter.
This Sunday, Lucy will skim Earth’s atmosphere as part of its first slingshot procedure, coming within just 240 miles of the ground — that’s lower than the International Space Station, which orbits 250 miles above Earth.
The close fly-by will give folks in Western Australia and also the Western U.S. a chance to view Lucy during its high-speed pass.
Take note, though, the fly-by comes with risks to the mission itself, as Lucy has to navigate Earth-orbiting satellites and large amounts of space debris. To prevent potentially catastrophic collisions, NASA has developed a system capable of anticipating potential hazards by enabling Lucy to execute small maneuvers to avoid a crash.
How to watch
At around 6:55 a.m. ET (6:55 p.m. local time) on Sunday, October 16, Lucy will hurtle over Western Australia. NASA’s spacecraft will be clearly visible to the naked eye as a bright light for up to seven minutes before disappearing as the spacecraft passes into Earth’s shadow.
Lucy will continue over the Pacific Ocean in darkness and emerge from the Earth’s shadow at 7:26 a.m. ET (4:26 a.m. PT). At this point, assuming the skies are clear, folks in the Western U.S. will be able to get a view of Lucy through binoculars as it appears in the southwestern sky. The video at the top of the page offers an accurate description of precisely where in the sky to look for Lucy.
“The last time we saw the spacecraft, it was being enclosed in the payload fairing in Florida,” said Hal Levison, Lucy principal investigator at the Colorado-based Southwest Research Institute. “It is exciting that we will be able to stand here in Colorado and see the spacecraft again. And this time Lucy will be in the sky.”
Following its fly-by, Lucy will then head rapidly away from Earth, passing by the moon before continuing out into interplanetary space.
Two years from now, Lucy will return for a second gravity-assist maneuver. Once it reaches its destination in 2025, the spacecraft will observe asteroid Donaldjohanson before heading into the leading Trojan asteroid swarm, flying past six targeted Trojan asteroids. Lucy will then return to Earth for a third gravity assist in 2030 that will send it toward the Patroclus-Menoetius binary asteroid pair in the trailing Trojan asteroid swarm.