Short Science, December 9, 2012
New images of the moon's crust point to a violent past in which it was battered by comets and asteroids during its first billion years, US scientists say.
Moon's crust more battered than thought
New images of the moon's crust point to a violent past in which it was battered by comets and asteroids during its first billion years, US scientists say. The new findings come from a pair of spacecraft named Ebb and Flow orbiting the moon and measuring its gravitational field. "It was known that planets were battered by impacts, but nobody had envisioned that the [moon's] crust was so beaten up," said Professor Maria Zuber, the Massachusetts Institute of Technology scientist leading the mission. "This is a really big surprise and is going to cause a lot of people to think about what this means for planetary evolution," she said of the findings, published last week in the journal Science. Unlike the earth's crust, which is repeatedly recycled through plate tectonics, the moon's crust dates back billions of years, offering clues to the birth of the solar system. AFP
Voyager 1 probe at 'magnetic highway'
Nasa's Voyager 1, which is heading out of the solar system, has reached a "magnetic highway" leading to interstellar space, scientists said. The probe, launched 35 years ago to study the outer planets, is now about 18 billion kilometres away. At that distance, it takes radio signals travelling at light speed 17 hours to reach earth. Reuters