In mid-February 2017, NASA's OSIRS-REx mission will search Earth's L4 Lagrange point for Trojan asteroids - small bodies that share Earth's orbit, and which may have been trapped there during the formation of our planet. Jim Green, the Director of Planetary Science at NASA, discusses OSIRIS-REx and its search for Earth's Trojan asteroids.
Music: "Meadows" by Daniel Pemberton, Atmosphere Music Ltd/Killer Tracks Music
Trojan asteroids accompany several of our solar system's planets, leading or trailing the planet in its orbit at the L4 and L5 Lagrange points. Detecting our own planet's Trojan asteroids from Earth is difficult because they appear close to the sun from our perspective. In mid-February 2017, NASA's OSIRS-REx mission will search for these elusive objects when the spacecraft passes by Earth's L4 Lagrange point, en route to asteroid Bennu in 2018.