Nasa intends to take up two new missions, which has the potential to study one of the earliest eras in the history of the solar system.

The Lucy and Psyche missions will proceed to formulation, with the aim of launching respectively in 2021 and 2023.

Nasa science mission directorate associate administrator in Washington Thomas Zurbuchen said: “Lucy will visit a target-rich environment of Jupiter's mysterious Trojan asteroids, while Psyche will study a unique metal asteroid that's never been visited before."

“This is an opportunity to explore a new type of world, not one of rock or ice, but of metal."

Scheduled to launch in October 2021, Lucy is a robotic spacecraft expected to arrive at its first slated destination, the main belt asteroid in 2025. Between 2027 and 2033, Lucy will explore six Jupiter Trojan asteroids.

Psyche will explore the 16 Psyche metal asteroid, which is three times farther away from the Sun than it is the Earth. This asteroid measures 130 miles (210km) in diameter and is thought to be mostly comprised of metallic iron and nickel, similar to Earth's core.

Scientists anticipate that this mission would help them in understanding how planets and other bodies separated into their layers, including cores, mantles and crusts, early in their histories.

Arizona State University psyche principal investigator Lindy Elkins-Tanton said: “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."

To be launched in October 2023, Psyche is also a robotic mission. It is expected to arrive at the asteroid in 2030, following an Earth gravity assist spacecraft manoeuvre in 2024 and a Mars flyby in 2025.