How long could you survive in the Mariana Trench?

The deepest point in Challenger Deep is close to 10,935 metres, where pressure is around 1,100 times sea-level atmospheric — roughly 1.1 tonnes on every square centimetre. A human body is mostly water and would not be crushed flat in the cartoon sense, but every gas-filled space would collapse instantly: lungs, sinuses, middle ear and gut. There is no version of a person surviving that unaided, and no breathing gas mixture that works at that pressure. Inside a pressure hull the environment is ordinary — Trieste in 1960 and several modern submersibles have carried people down and back — and the limit becomes battery, scrubber and oxygen capacity, typically half a day with large reserves. It is also completely dark and about 1-4 °C.

Physiology, not instruction. Every figure here is a population range under particular conditions, and individual variation is large — temperature, exertion, fitness and health move all of them substantially. Nothing on this page is medical advice.

Places

• How long could you survive in deep space? About fifteen seconds of consciousness, and roughly ninety seconds before the damage becomes irreversible.
• Could you survive on Mars? Unprotected, under two minutes. In a pressurised habitat, indefinitely — the limits become supply and radiation.
• How long can you survive in the death zone on Everest? Hours to a couple of days. Above about 8,000 metres the body deteriorates no matter what you do.
• How long can you survive adrift in the open ocean? In warm water with a raft, three to five days without drinking water — but immersion in cold water is measured in hours.
• How long could you survive on the Moon? About fifteen seconds of consciousness without a suit. With one, the record stay is 75 hours.
• How long can you survive in Antarctica? Minutes to an hour unprotected in a winter storm — or indefinitely, since around a thousand people overwinter there every year.
• How long can you survive in the Sahara Desert? Around a day without water in summer daytime heat, and several days if you can stay in shade and move only at night.
• How long could you survive on Venus? Seconds. The surface is 465 °C at ninety-two times Earth's atmospheric pressure — the hardest place in the solar system to land on.
• Could you survive on Jupiter? There is no surface to survive on — you would fall inward until pressure and heat ended it, within minutes.
• How close to the Sun could you survive? Nothing solid survives contact — but a shielded spacecraft has flown within about 6 million kilometres of the surface.
• How long could you survive on a desert island? Fresh water decides it. With a spring or reliable rain, years; without, about three days.
• How long can you survive on the International Space Station? Indefinitely while it is resupplied — it has been continuously crewed since November 2000.
• How long can you survive in the Arctic? Hours unprotected in winter — but roughly four million people live above the Arctic Circle permanently.
• How long can you survive in a cave? With water and warmth, months — people have done it deliberately. Without light or a way out, hypothermia is the clock.