A metre-sized asteroid called 2011 CQ1 was spotted zipping only 5480 kilometres above the Earth’s surface. That is the closest near miss on record, beating the previous record holder, a rock that buzzed Earth in 2004 called 2004 FU162, by a few hundred kilometres.
When something that small comes close to our planet, Earth’s gravity is sure to bend its orbit. In this case, the approach was so close that the little asteroid’s path bent by 60 degrees, reports Don Yeomans of NASA’s Jet Propulsion Laboratory in Pasadena, California.
Short of collisions with a planet, that’s the biggest orbital change ever recorded by observers. It was large enough to shift the asteroid from one category of objects into another. As Yeomans and his JPL colleague Paul Chodas explain in an online update:
Gravitational encounters between objects large and small have been rearranging the solar system since it formed some 4.56 billion years ago. We now believe even planets have been shuffled in their orbits. In this case, we had the good fortune to spot a very large change in the orbit of one very small object around the sun.
But now that 2011 CQ1 has had its 15 minutes of fame, we are unlikely to spot the small, dim object again, says Emily Lakdawalla of the Planetary Society, a space advocacy group in California: “We’ll probably never be close enough to it again to be able to pick its dim light out from the background of stars.”