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moon · moon of Neptune

Triton compared to the Moon

Neptune’s largest moon. It orbits backwards, is probably a captured dwarf planet, and has active nitrogen geysers.

Can you see it?

No small telescope will show you this one; it is here to be understood, not spotted.

How big is Triton compared to the Moon?

Triton is roughly four fifths as wide as the Moon.

How far away is Triton from Neptune compared to the Earth-to-Moon distance?

Triton sits about nine tenths of the Earth-to-Moon distance from Neptune.

How long does Triton take to go once round Neptune?

Triton takes about 5.9 Earth days to go once round Neptune.

How long is a day on Triton compared to Earth?

Triton turns round once in about 5.9 Earth days; Earth takes about 24 hours. Its orbit takes exactly as long, so Triton keeps the same face turned towards Neptune the whole time. And Triton spins backwards.

How much mass does Triton have compared to the Moon?

Triton has roughly one quarter the mass of the Moon.

What is the volume of Triton compared to the Moon?

Triton has roughly half the volume of the Moon.

How much would you weigh on Triton compared to Earth?

On Triton you would weigh roughly one thirteenth of what you weigh on Earth.

How hot is Triton compared to Earth?

On Triton it is −235 °C. Earth runs from −89.2 to 56.7 °C.

Worth knowing about Triton

Where it came from
A moon born alongside Neptune would go round the same way the planet spins; Triton goes the other way, which is why it is thought to have been caught later.
The machines we sent
Voyager 2 (1989) — the only spacecraft ever to visit.
Triton — Rendered from a map, not photographed. The plain part was never seen.
The numbers
Across2,705 km
Distance from the centre of the planet it orbits354,759 km
Once round its orbit5.877 days
One spin5.877 days — and it turns the other way, so the Sun there rises in the west
Temperature−235 °C
Also found therenitrogen, methane, water

How anyone knows this

Games it appears in

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