Asteroid 2012 DA14 Speeds Away From Earth
The solar system is home to myriads of asteroids, small bodies left over from its formation. More are discovered every year. Only the largest asteroids are truly spherical, drawn into this shape by their self-gravity: most appear to be completely irregular in shape. They rotate with periods that are generally a matter of hours. And they have a wide range of compositions, from dense iron metal to low density rocks rich in organic compounds. Asteroids are often described as rubble piles, or loosely bound collections of smaller rock fragments. But these characteristics are not well understood, which is what led Dr. Moskovitz and his team to their study.
The first asteroids were discovered orbiting the Sun in the space between Mars and Jupiter, but recent discoveries make it clear that they are found throughout the solar system. Of particular interest from most people’s point of view are those characterized as near-Earth asteroids. These are objects whose orbits cross that of the Earth and allow them to make a close pass to our planet, with the potential of colliding on one of those passes. These asteroids include 2012 DA14 which was discovered just a year ago. Its orbit is similar to the Earth, with a period of 366 days, but with a more elliptical shape and an inclination of 11 degrees to the plane of the Earth’s orbit around the Sun. Following its discovery and the recognition that it would make a very close pass on Feb. 15, 2013, the team planned an observing campaign using telescopes in both the northern and southern hemisphere, including facilities in Australia, New Zealand, Tasmania, South Africa, Spain, Israel, Hawaii, Massachusetts, and Arizona.
2012 DA14 is not expected to visit the vicinity of the Earth any time for at least the next century, but as we saw with the impact in Russia on the same day as the flyby, there are many thousands of near-Earth asteroids out there that can be dangerous. Observing campaigns like the present one will mean that scientists will have a much better understanding of the properties of near-Earth asteroids, and their potential for making trouble should they get too close!