lunar image of the month

november: earth & moon

Seen from a distance of four million miles by NASA's Galileo probe, the Earth-Moon system presents an interesting spectacle. The Moon is the fifth largest satellite in the solar system... larger even than the planet Pluto. Relative to its primary - the Earth - it is nearly the largest of all, being beaten only by Pluto's moon Charon. Both Earth-Moon and Pluto-Charon can reasonably be considered as double planets.

The Earth has an albedo of 0.36, meaning 36% of light shining on it is reflected. The Moon, however, has an albedo on only 0.076, only 1/5 as reflective. Although it seems bright in the sky at night, this comparison shows it for the dark object it is.

Image: Galileo Project, JPL, NASA.