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.
Read more about this topic: Earth Trojan Asteroid
Famous quotes containing the word significance:
“For a parent, it’s hard to recognize the significance of your work when you’re immersed in the mundane details. Few of us, as we run the bath water or spread the peanut butter on the bread, proclaim proudly, “I’m making my contribution to the future of the planet.” But with the exception of global hunger, few jobs in the world of paychecks and promotions compare in significance to the job of parent.”
—Joyce Maynard (20th century)
“History is the interpretation of the significance that the past has for us.”
—Johan Huizinga (1872–1945)
“Politics is not an end, but a means. It is not a product, but a process. It is the art of government. Like other values it has its counterfeits. So much emphasis has been placed upon the false that the significance of the true has been obscured and politics has come to convey the meaning of crafty and cunning selfishness, instead of candid and sincere service.”
—Calvin Coolidge (1872–1933)