The GRAIL mission was launched by NASA on September 10, 2011 and consisted of two small spacecraft, GRAIL A and GRAIL B. The acronym GRAIL stands for Gravity Recovery and Interior Laboratory and aimed to measure in very high quality the gravitational field of the moon. The two spacecraft, nicknamed Ebb and Flow, orbited the Moon for almost a year, starting on 31 December 2011, and ending on December 17, 2012 when they both impacted the surface of the moon. In the images generated, see above, the red zones are areas of above average gravitational pull, while blue areas are below the average gravitational attraction. The data gathered by Ebb and Flow will be used to help create much more accurate fuel consumption models for future missions to and around the moon.