Happy New Year! Just four days into 2017 NASA announced its pick for two new Discovery missions to explore our solar system: one to investigate a few of the “Trojan” asteroids that Jupiter has gathered into its orbit with its mighty gravity, and another to visit the remains of an ancient planet’s metallic core!
“These are true missions of discovery that integrate into NASA’s larger strategy of investigating how the solar system formed and evolved,” says Jim Green, NASA’s Planetary Science Director. “We’ve explored terrestrial planets, gas giants, and a range of other bodies orbiting the sun… These additional pieces of the puzzle will help us understand how the sun and its family of planets formed, changed over time, and became places where life could develop and be sustained – and what the future may hold.”
Find out these new missions’ names, launch dates, and more below:
Lucy, a robotic spacecraft, is scheduled to launch in October 2021. It’s slated to arrive at its first destination, a main belt asteroid, in 2025. From 2027 to 2033, Lucy will explore six Jupiter Trojan asteroids. These asteroids are trapped by Jupiter’s gravity in two swarms that share the planet’s orbit, one leading and one trailing Jupiter in its 12-year circuit around the Sun. The Trojans are thought to be relics of a much earlier era in the history of the solar system, and may have formed far beyond Jupiter’s current orbit.
(Note: Lucy is named after a 3.18-million-year-old hominid fossil discovered in Ethiopia in 1974, because, like the famous fossil, it will help us “revolutionize the understanding of our origins.” Interestingly enough Lucy’s first target will be a main belt asteroid named after Donald Johanson, Lucy’s discoverer.)
Lucy will build on the success of NASA’s New Horizons mission to Pluto and the Kuiper Belt, using newer versions of the RALPH and LORRI science instruments that helped enable the mission’s achievements. Several members of the Lucy mission team also are veterans of the New Horizons mission. Lucy also will build on the success of the OSIRIS-REx mission to asteroid Bennu, with the OTES instrument and several members of the OSIRIS-REx team.
“Understanding the causes of the differences between the Trojans will provide unique and critical knowledge of planetary origins, the source of volatiles and organics on the terrestrial planets, and the evolution of the planetary system as a whole.”
— Dr. Catherine Olkin, Lucy mission deputy principal investigator, SwRI
The Psyche mission will explore one of the most intriguing targets in the main asteroid belt – a giant metal asteroid, known as 16 Psyche, about three times farther away from the Sun than is the Earth. This asteroid measures about 130 miles (210 kilometers) in diameter and, unlike most other asteroids that are rocky or icy bodies, is thought to be comprised mostly of metallic iron and nickel, similar to Earth’s core. Scientists wonder whether Psyche could be an exposed core of an early planet that could have been as large as Mars, but which lost its rocky outer layers due to a number of violent collisions billions of years ago.
The mission will help scientists understand how planets and other bodies separated into their layers – including cores, mantles and crusts – early in their histories.
Psyche is targeted to launch in October 2023 and will arrive at the asteroid in 2030.
NASA’s Jim Green talks about each of these missions in the video below:
“This is an opportunity to explore a new type of world – not one of rock or ice, but of metal. 16 Psyche is the only known object of its kind in the solar system, and this is the only way humans will ever visit a core. We learn about inner space by visiting outer space.”
– Lindy Elkins-Tanton, Psyche Principal Investigator, Arizona State University
These new Discovery missions follow in the footsteps of MESSENGER, Dawn, Kepler, Mars Pathfinder, and others that used relatively low-cost yet innovative technology to maximize scientific return and ultimately provide unprecedented and invaluable data from a variety of different worlds. Flagship missions like Voyager, Curiosity (MSL), and New Horizons may get a lot of attention but, since 1992, NASA’s Discovery program has also been unlocking many of our solar system’s deepest secrets.