In July 2020, NASA launched its Lucy Mission to explore the Trojans – asteroids that share the orbit of the giant planet Jupiter. After travelling for nearly two years, the mission has finally arrived at its destination. But what the team found was much more than they had expected.
The Lucy Mission is a great example of how even the most carefully planned mission can still encounter unanticipated surprises. The mission team initially set out to explore six Trojans asteroids, which are trans-Neptunian bodies that can be found near the orbit of Jupiter. With the New Horizons probe, scientists have already explored the Jupiter-family of asteroids, but they still knew little of the Trojans, which are believed to have formed alongside the planet four billions years ago.
When the mission finally arrived at the first target asteroid, scientists were surprised to find that it was not a single large body, as expected, but two bodies orbiting each other. This binary Trojans asteroid is the first of its kind to be explored by spacecraft, and it now has the name ‘Lucy’, inspired by the Beatles’ song ‘Lucy in the Sky with Diamonds’.
In addition, the Lucy team also got a bonus observation as their craft passed by a secondary target asteroid – a single Trojans asteroid called Eurybates. As mission director Harold Levison explained, “we thought that we were just going to fly by it, but it turned out that the asteroid was very special. It had a really bizarre shape.” This strange shape is likely due to a period of collisions between itself and other asteroids, making it a great target for future research.
The Lucy mission has already achieved far more than it initially set out to do and shows the importance of being prepared for the unknown on any interstellar mission. While the mission team is excited by the unexpected discoveries they have made, they are still short of their original goal of studying six Trojans asteroids. Thankfully, they still have four such asteroids to visit and who knows what other surprises are in store?
With the Lucy mission, NASA has demonstrated the potential of outer space exploration for uncovering new and unknown discoveries. From its two surprisingly binary asteroids to its peculiarly shaped secondary target, the Lucy mission will be remembered for a long time to come. As they continue to explore our solar system, let us hope that other such missions will bring back more such curiosities from the unknown.