Astronomers Capture Meteorite Strike On Moon – This is a cool little story. Scientists are monitoring the moon for meteorite strikes as part of NASA’s plans to return to the moon for a long term exploration. Since the moon lacks a protective atmosphere, even small bits of rock impact the surface. NASA wants to know how often these impacts occur, so the agency is funding a project to monitor the moon with telescopes. Almost from the start, researchers caught this impact on May 2, 2006 in the Sea of Clouds (Mare Nubium). They estimate it was a 25 cm meteoroid travelling at 38 km/s and that it carved out a 14 meter wide, 3 meter deep crater. FYI, 38 km/s is 85,000 mph.
Upper Limit For Moons Explained – It’s an interesting conundrum; Jupiter, Saturn and Uranas all have dozens of moons, yet in each case the combined mass of the moons equals 0.01% of the parent planet. Well a new model seeks to explain how these gas giants garnered such an array of moons. Basically any moon larger than this 0.01% limit was drawn too close to the gas giant and absorbed into the planet. The only exception to this rule was Neptune’s moon Triton, which astronomers think is a captured object that did not form with Neptune.