The Eruption in Alphonsus
A Soviet astronomer said his instrument had caught gas erupting from the central peak of a crater on the Moon.
What was reported
On the night of 3 November 1958, the Soviet astronomer Nikolai Kozyrev was studying the crater Alphonsus with a telescope fitted to split light into its colours. He saw the central peak turn hazy and reddish, and his recording showed a pattern he took as the signature of hot gas being released from the Moon.
At a time when most astronomers thought the Moon geologically dead, his claim of a volcanic outburst caused a stir.
Explanations offered
Some astronomers accepted it as the first evidence of gas escaping from the Moon; others thought his recording could be explained by the instrument or by sunlight. It has never been repeated or confirmed. Later missions did find that small amounts of gas, such as radon, seep out of the Moon in places.
- When
- 3 November 1958
- Where
- Alphonsus crater, the Moon
- Witnesses
- Astronomer Nikolai Kozyrev, at the Crimean Astrophysical Observatory
- Status
- Disputed
Famous cases are real, widely reported events. Each file sets out what witnesses said and the explanations that have been offered, without taking a side.