Triton
Where is Triton?
Look south, about 38° up at 00:15 in Pisces.
- Rises
- 18:12
- Highest
- 00:14
- Sets
- 06:15
- Best after dark
- 00:15 · 38°
Can I see Triton tonight?
Triton always stays within a small fraction of a degree of Neptune, so its position tonight is Neptune’s position.
From London tonight, Triton is above the horizon after dark. It’s highest after dark at 00:15, in the south at 38°.
This is position and timing only: clouds, haze and light pollution aren’t included.
What does Triton look like?
Eyes
Not visible.
Binoculars
Not visible.
Telescope
Around magnitude 13.5 and never far from Neptune. A telescope of about 200 mm (8 inches) or more, high magnification and steady air are needed to see it as a faint point beside Neptune’s tiny disk.
About Triton
Triton is Neptune’s largest moon, about 2,700 km across. It was found by William Lassell in 1846, just 17 days after Neptune itself was discovered.
It orbits Neptune backwards, opposite to the planet’s spin. No large moon could form that way, so Triton was probably a Kuiper Belt object, like Pluto, that Neptune captured long ago.
When Voyager 2 flew past in 1989, it found one of the coldest surfaces in the Solar System, a pinkish crust of frozen nitrogen, and dark streaks from geyser-like plumes. Triton’s orbit is slowly shrinking, and in the far future it is expected to break apart near Neptune.
Triton is one of the few moons known to be geologically active. Its surface temperature is around −235 °C, yet it has a thin nitrogen atmosphere, few impact craters and an unusual wrinkled region nicknamed cantaloupe terrain.
Triton holds more than 99% of the mass of everything that orbits Neptune, apart from Neptune itself. It is even larger than the dwarf planet Pluto.
Neptune and its moons
Questions
What telescope do I need for Triton?
Why does Triton orbit backwards?
Sources: SkyMate; star chart: Wikidata (CC0). Positions computed for your place and time with astronomy-engine. Data & Licences