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How does Triton’s atmospheric pressure compare with Earth’s?
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Triton
Image of Triton, Neptune's largest satellite, captured by a camera aboard Voyager 2, 1989.
Triton’s atmosphere is extremely tenuous compared to Earth’s. While standard sea-level atmospheric pressure on Earth is defined as 1,013.25 millibars (or 1.01325 bar), the near-surface pressure on Triton is less than 0.00002 bar.12
This means that the pressure on the surface of Triton is more than 50,000 times lower than the standard atmospheric pressure experienced at sea level on Earth. Triton’s atmosphere is formed by the sublimation of frozen nitrogen due to the moon's remarkably low surface temperature of 38 K (−235 °C).2