Earth Trojan Asteroid - Significance

Significance

The orbits of Earth trojans could make them less energetically costly to reach than the Moon, even though they are dozens of times more distant. Such asteroids could one day be useful as sources of elements that are rare near the Earth's surface. On Earth, siderophiles such as iridium are difficult to find, having largely sunk to the core of the planet shortly after its formation. A small asteroid could be a rich source of such elements even if its overall composition is similar to Earth's; because of their small size, such bodies would lose heat much more rapidly than a planet once they had formed, and so would not have melted, a prerequisite for differentiation. Their weak gravitational fields also would have inhibited significant separation of denser and lighter material; a mass the size of 2010 TK₇ would exert a surface gravitational force of less than 0.00005 times that of Earth.