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NASA Astronomy Picture of the Day

🌌 NASA Astronomy Picture of the Day

Triton: Neptune's Largest Moon

Date: 1996-10-10

Triton: Neptune's Largest Moon

View HD Image

Explanation:

Today marks the 150th anniversary of the
discovery of Triton. On October 10 1846, William Lassell
was observing the newly discovered
planet Neptune. He was attempting
to confirm his observation, made just the previous week, that Neptune had a ring. But this time he discovered that Neptune
had a satellite as well. Lassell soon proved the ring
was product of his new telescope's distortion, but the satellite
Triton
remained. The above picture of Triton
was taken in 1989 by the only spacecraft ever to pass Triton:
Voyager 2. Voyager 2 found fascinating terrain,
a thin atmosphere, and even evidence for ice volcanoes on this
world of peculiar orbit and spin. Ironically, Voyager 2 also confirmed the existence of complete thin rings around Neptune
- but these would have been quite invisible to Lassell!