An artist’s conception of the Lucy spacecraft flying by the Trojan Eurybates – one of the six diverse and scientifically important Trojans to be studied.

NASA will launch two space missions to asteroids to gather evidence about the early days of the solar system.

The unmanned Lucy and Psyche missions will launch in 2021, and 2023, respectively. Both will travel to asteroids — Lucy to a cluster of asteroids near Jupiter known as the Trojan asteroids, and Psyche to an unexplored, and unusual, large asteroid made of metal in the main asteroid belt.

The Trojan asteroids near Jupiter are thought to be remnants of an earlier period in the history of the solar system.

"This is a unique opportunity," said Harold F. Levison, principal investigator of the Lucy mission from the Southwest Research Institute in Boulder, Colorado, in a news release."Because the Trojans are remnants of the primordial material that formed the outer planets, they hold vital clues to deciphering the history of the solar system. Lucy, like the human fossil for which it is named, will revolutionize the understanding of our origins."

The Psyche mission will travel to the asteroid 16 Psyche, which is comprised mostly of iron and nickel, unlike most asteroids, which tend to be rocky or icy, according to the release.

The metals are also found in the Earth's core, leading researchers to think the asteroid may be the remnants of a Mars- or Earth-like planet that long ago lost its rocky outer layers.

"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," said Psyche Principal Investigator Lindy Elkins-Tanton, of Arizona State University.

