On the Moon, they would only be needed for 13.7 days - the length of the lunar night.

On November 24, 1967, the spacecraft was shut down for the 2 week lunar night.

The call came two weeks later, in the middle of the night-the real lunar night.

A polonium-210 radioactive heat source was used to keep the rover warm during the long lunar nights.

We spent a lot of time during the long lunar nights using minimal power, trying to conserve.

Two men had suited up and stepped out into a lunar night.

The long lunar night was nearing the end of its second week.

It was during the lunar night that most of the exploration was done.

It was evidently brittle as glass in the cold of the lunar night.

It would also be a suitable term for an observer on the moon seeing the Earth during the lunar night.