NASA’s Interstellar Boundary Explorer has made the first detection of neutral atoms coming from the Moon (background image). The color-coded data toward the bottom shows the neutral particles and geometry measured at the Moon December 3, 2008. IBEX spins at four rotations per minute with its field of view sweeping over the Moon each spin over about 10 hours. The neutral atoms are summed in 6° bins with the lunar direction indicated by the white arrow. IBEX detects particles produced by reflection and neutralization of the incident solar wind protons at toward the spacecraft. The Earth, Moon, and spacecraft shown toward the top are not to scale.
SWRI, San Antonio, Texas