NASA scientists announced today that they have created multiple radar images showing the near-Earth asteroid named 2007 PA8. The images were generated using data collected from the 70-meter Deep Space Network antenna in Goldstone, California on October 28 through October 30. During that time, the asteroid ranged from 10 million kilometers (6.5 million miles) to only 9 million kilometers (5.6 million miles) from Earth.
NASA states that 2007 PA8 is an elongated, irregularly shaped object about 1.6 kilometers (one mile) wide. The asteroid also has ridges and, "perhaps," craters. The data also suggests that the object rotates very slowly, taking three to four days for a full rotation.
2007 PA8 was chosen, scientists said, because of its size and proximity to Earth at its closest approach. On the morning of November 5 the asteroid was only 6.5 million kilometers (4 million miles) from Earth, which is around 17 times the distance from the Earth to the moon.
Much like this week's announcement of the Hergenrother comet break-up, NASA assuaged fears by stating that the trajectory of 2007 PA8 is well understood, and that this month's approach was the asteroid's closest Earth flyby for at least the next 200 years. The object was tracked and characterized by the Near-Earth Object Observations Program, or "Spaceguard." The program uses ground and space telescopes to detect, track, and characterize asteroids and comets passing close to Earth. It then plots their orbits to determine whether they could be "potentially hazardous" to Earth.
(Image courtesy NASA/JPL-Caltech/Gemini)