Definition of nightside in English:
1 Astronomy The side of a planet or moon that is facing away from the sun and is therefore in darkness.
- Much of the time, those energetic particles trickle in through the rear flanks of Earth's magnetic tail - on the nightside - and near the polar regions.
- The disk is Earth with its nightside facing the Moon.
- The first satellite, Geotail, was launched in 1992 by Japan's Institute of Space and Astronautical Science to study the distant reaches of Earth's magnetic tail, the region downwind on the nightside of Earth.
Definition of nightside in:
- British & World English dictionary