It was 0.7 lunar distances at closest, with an apparent magnitude of 18.5-19.0.

On 8 November 2011 it passed 0.85 lunar distances (324,900 kilometers; 201,900 miles) from the Earth.

It approaches to within 30 Gm, or about 80 lunar distances, of Earth 17 times in the 21st century.

The navigator then consults a prepared table of lunar distances and the times at which they will occur.

Having measured the lunar distance and the heights of the two bodies, the navigator can find Greenwich time in three steps.

The first correction to the lunar distance is the distance between the limb of the Moon and its center.

The almanac gives lunar distances as they would appear if the observer were at the center of a transparent Earth.

A lunar distance changes with time at a rate of roughly half a degree, or 30 arc-minutes, in an hour.

The older method, called "lunar distances", was refined in the 18th century.

Mostly the same vehicle, it lacked the larger antenna needed to communicate at lunar distance.