Lucy: The First Mission to Jupiter’s Trojans
During the course of its mission, Lucy will fly by six Jupiter Trojans. This time-lapsed animation shows the movements of the inner planets (Mercury, brown; Venus, white; Earth, blue; Mars, red), Jupiter (orange), and the two Trojan swarms (green) during the course of the Lucy mission.
Credits: Astronomical Institute of CAS/Petr Scheirich (used with permission)
Jupiter's swarms of Trojan asteroids may be remnants of the primordial material that formed the outer planets, and serve as time capsules from the birth of our Solar System more than 4 billion years ago. The Trojans orbit in two loose groups that orbit the Sun, with one group always ahead of Jupiter in its path, the other always behind. At these two Lagrange points the bodies are stabilized by the Sun and Jupiter in a gravitational balancing act.
These primitive bodies hold vital clues to deciphering the history of the solar system, and perhaps even the origins of life and organic material on Earth.
Lucy will be the first space mission to study the Trojans. The mission takes its name from the fossilized human ancestor (called “Lucy” by her discoverers) whose skeleton provided unique insight into humanity's evolution. Likewise, the Lucy mission will revolutionize our knowledge of planetary origins and the formation of the solar system.
Lucy will launch in October 2021 and, with boosts from Earth's gravity, will complete a 12-year journey to seven different asteroids — a Main Belt asteroid and six Trojans, the last two members of a “two-for-the-price-of-one” binary system. Lucy’s complex path will take it to both clusters of Trojans and give us our first close-up view of all three major types of bodies in the swarms (so-called C-, P- and D-types).
The dark-red P- and D-type Trojans resemble those found in the Kuiper Belt of icy bodies that extends beyond the orbit of Neptune. The C-types are found mostly in the outer parts of the Main Belt of asteroids, between Mars and Jupiter. All of the Trojans are thought to be abundant in dark carbon compounds. Below an insulating blanket of dust, they are probably rich in water and other volatile substances.
No other space mission in history has been launched to as many different destinations in independent orbits around our sun. Lucy will show us, for the first time, the diversity of the primordial bodies that built the planets. Lucy’s discoveries will open new insights into the origins of our Earth and ourselves.
Dr. Levison's principal research interests lie in the area of the dynamics of astronomical objects. In particular, he focuses on the formation and long-term behavior of the solar system bodies. Dr. Levison's work includes studies of the formation of both giant and terrestrial planets, the long-term dynamical behavior of comets, the dynamics of objects in the Kuiper belt, the origin and stability of Trojan asteroids, and the formation of satellites. In 1997, he, with Martin Duncan, predicted the existence of the Scattered Comet Disk. He is perhaps best known, however, for his work on the early dynamical evolution of the outer Solar System, and is an author of the most comprehensive model to date.
Dr. Levison is also the co-author of SWIFT , which is a software package for integrating orbits of solar system bodies. SWIFT is freely available and will run on most UNIX workstations.