Astrophysics (Index)About


(Gravity Recovery and Interior Laboratory)
(2011 NASA lunar orbiters to collect gravity data)

GRAIL (for Gravity Recovery and Interior Laboratory) was a NASA lunar mission to study the Moon's gravitational field. Two separately-launched spacecraft (GRAIL A aka Ebb and GRAIL B aka Flow) exchanged timing information with each other and with stations on Earth, to record precise location information of each over time. Through analysis, much information on the gravitational field, thus on gravity anomalies could be determined. The primary science data collection required only three months and after some additional data collection, the probes were deliberately crashed into the moon a year after the launch. Instruments:

Further reading: