The Grail Mission

Using a precision formation-flying technique, the twin GRAIL spacecraft mapped the moon’s gravity field, as depicted in this artist’s rendering. Radio signals traveling between the two spacecraft provided scientists the exact measurements required to produce the most accurate gravity map of the moon ever made. The mission answered longstanding questions about Earth’s moon, and provided scientists with a better understanding of how Earth and other rocky planets in the solar system formed. GRAIL was a part of NASA’s Discovery Program. Image credit: NASA/JPL-Caltech

Using a precision formation-flying technique, the twin GRAIL spacecraft mapped the moon’s gravity field, as depicted in this artist’s rendering. Radio signals traveling between the two spacecraft provided scientists the exact measurements required to produce the most accurate gravity map of the moon ever made. The mission answered longstanding questions about Earth’s moon, and provided scientists with a better understanding of how Earth and other rocky planets in the solar system formed. GRAIL was a part of NASA’s Discovery Program. Image credit: NASA/JPL-Caltech