10 October 1846: Triton, Neptune's largest moon, is discovered
In 60 words
On 10 October 1846, just 17 days after the planet Neptune was discovered, the English astronomer William Lassell found its largest moon, Triton. Triton orbits backwards, against Neptune's spin, and has geysers of nitrogen, seen by Voyager 2 in 1989.
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