A patch of very faint nebulous light sometimes seen in the night sky opposite the position of the sun. It is thought to be the image of the sun reflected from gas and dust outside the atmosphere.
- ‘But the gegenschein is very faint, a few magnitudes fainter than the Milky Way.’
- ‘The gegenschein is distinguished from zodiacal light by the high angle of reflection.’
- ‘The gegenschein is visible as faint patch of light at the center of the image.’
- ‘The spectrum of the gegenschein is similar to that of the Sun, and it is generally believed that it is the result of the reflection of sunlight from meteoric material or other dust in the Earth's orbital plane.’
- ‘There have been reports that under very favorable viewing conditions the zodiacal light extends to the gegenschein.’
Late 19th century: German Gegenschein, from gegen ‘opposite’ + Schein ‘glow, shine’.
We take a look at several popular, though confusing, punctuation marks.