NASA announces two missions for study of asteroids

NASA has announced two space exploration missions for the study of asteroids vital to deciphering the origins of the solar system.

NASA said on Wednesday that the missions would send spacecraft to several asteroids to investigate the formation of planets and other bodies in the solar system roughly 10 million years after the birth of the sun.

The first mission, known as Lucy, would launch in 2021. The robotic mission would fly by and study the physical properties of the Trojan asteroids, which shared Jupiter's orbit. According to scientists, the Trojans are remnants of the material that formed the solar system's more distant planets.

These asteroids are considered to be ''fossils'' of planet formation and could provide clues about how the outer solar system came to be, according to Lucy principal investigator Harold F Levison of the Southwest Research Institute in Boulder, Colorado.

''The big outer planets had a profound effect, we believe, on how the Earth formed,'' Levison told NewsHour, www.pbs.org reported. ''So understanding how they formed has impacts on how we understand how the Earth got here.''

The second mission would explore a large metal asteroid known as 16 Psyche. The asteroid, which is around 150 miles in diameter is made of metallic iron and nickel. Some scientists believe it was an exposed core from an early planet, which likely lost its rocky outer layer due to collisions with other space objects.

The Psyche space probe will visit the giant metal asteroid in 2030, and Lucy would investigate a half-dozen Trojan asteroids along Jupiter's orbital plane from 2027 to 2033. By exploring the Jupiter's  Trojans, scientists would gain a better understanding of these objects and how they got caught in Jupiter's gravitational field. The mission would also allow scientists to learn more about the chemical composition of the early solar system.

Mars, Neptune, and Earth had their own Trojan objects, but Jupiter had a Trojan swarm unlike any other. The Jovian Trojans, as they are called, are organised into two giant clumps - one in front of the gas giant and one that trailed behind.