The spacecraft named Lucy will be hurled into space on
Saturday on the 12-year expedition. Named after an ancient fossil of a
pre-human ancestor, Lucy will become the first solar-powered spacecraft to
venture so far from the Sun, and will observe more asteroids than any probe
before it— eight in all. Additionally, Lucy will make three Earth flybys for
gravity assists, making it the first spacecraft to return to our planet's
vicinity from the outer solar system.
Lucy's first encounter will be in 2025 with asteroid Donald
Johanson in the Main Belt, between Mars and Jupiter. Between 2027 and 2033, it
will encounter seven Trojan asteroids—five in the swarm that leads Jupiter, and
two in the swarm that trails the gas giant.
On board are a suite of instruments that will study these
worlds, including a diamond beamsplitter that splits beams of light so
scientists can determine the temperatures and surface properties of an
asteroid, NASA said in a statement.
"Each one of those asteroids, each one of those
pristine samples, provide a part of the story of the solar system, the story of
us," Thomas Zurbuchen, associate administrator of NASA's Science Mission,
told reporters
The Jupiter Trojan asteroids, thought to number well over
7,000, are leftover raw materials from the formation of our system's giant
planets -- Jupiter, Saturn, Uranus and Neptune. Scientists believe they hold
vital clues about the composition and physical conditions in the protoplanetary
disk from which all the Sun's planets, including Earth, formed.