Post by patrickm on Dec 24, 2011 9:57:07 GMT -6
Researchers: Temporary secondary asteroids orbit earth at any given time
Read the rest of Natalie Wolchover's story at MSNBC.
Earth has two moons, a group of scientists argues. One is that waxing and waning nightlight we all know and love. The other is a tiny asteroid, no bigger than a Smart Car, making huge doughnuts around Earth for a while before it zips off into the distance.
That's the scenario posited by the scientists in a paper published Dec. 20 in the planetary science journal Icarus. The researchers say there is a space rock at least 1 meter (3.3 feet) wide orbiting Earth at any given time. They're not always the same rock, but rather an ever-changing cast of "temporary moons."
In the scientists' theoretical model, our planet's gravity captures these asteroids as they pass near us on their way around the sun. When one is drawn in, it typically makes three irregularly shaped swings around Earth — sticking with us for about nine months — before hurtling on its way.
That's the scenario posited by the scientists in a paper published Dec. 20 in the planetary science journal Icarus. The researchers say there is a space rock at least 1 meter (3.3 feet) wide orbiting Earth at any given time. They're not always the same rock, but rather an ever-changing cast of "temporary moons."
In the scientists' theoretical model, our planet's gravity captures these asteroids as they pass near us on their way around the sun. When one is drawn in, it typically makes three irregularly shaped swings around Earth — sticking with us for about nine months — before hurtling on its way.
Read the rest of Natalie Wolchover's story at MSNBC.