2007 in spaceflight Moon. Japan's Kaguya orbiter, along with the smaller Okina and Ouna relay spacecraft, was launched on 14 September. The spacecraft entered Selenocentric orbit on 3 October. China launched its first Lunar probe, Chang'e 1, on 24 October, with the spacecraft entering Selenocentric orbit on 5 November. In 2009, two satellites launched into highly elliptical Earth orbits in 2007 as part of the THEMIS mission were also sent to the Moon. They are expected to arrive in October 2010. In August, the NASA Phoenix spacecraft was launched towards Mars, followed by the Dawn mission to the Asteroid belt in September. Cassini
Marius Hills The hole, first discovered by the Japanese SELenological and ENgineering Explorer (SELENE) and then later imaged by the Lunar Reconnaissance Orbiter has been the subject of much research and speculation. There is a possibility that this feature could be a skylight in a lava tube. The depth of this hole is estimated to be between and its width is estimated to be several hundreds of meters. This tube could provide radiation shielding for a future underground lunar colony. However, it is unclear whether the tube is open or accessible. Two other lunar sites have been found by remote sensing, including