GRAIL A and B are lunar satellites launch by NASA that will be studying the gravitational field of the Moon (see GRAIL). The spacecrafts just arrived at the moon on December 31st 2011 and January 1st 2012. To get the general public involved in the mission, NASA decided to hold a competition for elementary school students in which they proposed new, more creative names for GRAIL A and B. The winners are a class of fourth grade students from Montana, who came up with the names "Ebb" and "Flow". Ebb means to move back or away (like a receding tide), where as flow means to move forward, like a flowing stream. The Moon's gravity is what causes the tides to occur, and since GRAILS primary mission is to study the Moon's gravity and how it affects Earth, these names are quite appropriate. Keep an eye out for other space related competitions that you can participate in on the NASA website: www. NASA.gov
Image Credit: NASA
