Lucy blasts off to seek out the solar system’ s origins

Strange asteroids near Jupiter may explain how the planets formed.

On 16 October, the US space agency NASA launched its latest mission to explore the solar system. The new probe is called Lucy and it was launched using an Atlas V rocket from Kennedy Space Center in Florida, US. Lucy will travel to a previously unexplored region of space, visiting a mysterious group of asteroids called the Trojans. These space rocks circle the Sun at the same distance as Jupiter but they clump together in two clouds that orbit some way ahead and behind the giant planet itself.

Lucy is named after a famous fossil of an early human relative, discovered in Ethiopia in 1974. The Trojans are made from material left behind when the planets formed about 4.5 billion years ago, and some scientists view them as “fossils” from this ancient period. Mission scientists hope that, just as the ancient Lucy shed light on human origins, so her new namesake will deliver fresh insights into how the solar system was born.

During its 12-year mission, Lucy will study seven Trojans – three individual objects and two pairs of asteroids orbiting each other. On the way there, it will fly past a 2.5-mile-wide rock in the solar system’s main asteroid belt (between the orbits of Mars and Jupiter), which has been named Donaldjohanson after the fossil Lucy’s co-discoverer. “It will still be several years before we get to the first Trojan asteroid,” said principal investigator Hal Levison, “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 instruments will look at the shape, surface features, make-up and temperature of the Trojans. This will help scientists work out if they are made from the same materials as Jupiter’s moons. It will also help to answer whether the asteroids formed in that part of the solar system or if they were born elsewhere and got pulled into their current orbits later.

“Lucy embodies NASA’S enduring quest to push out into the cosmos for the sake of exploration and science, to better understand the universe and our place within it,” said Bill Nelson, who is the boss of NASA. “I can’t wait to see what mysteries the mission uncovers!”

Lucy blasts off on its long journey.