How close to the Sun could you survive?

The visible surface of the Sun is about 5,500 °C and the corona above it is hotter still by a factor of hundreds, though it is so thin that its heat content is low. Any material object approaching would vaporise, and there is no engineering path around it at close range. What is possible is standing off behind a shield: NASA's Parker Solar Probe passed within roughly 6.1 million kilometres of the surface with a carbon-composite heat shield running around 1,400 °C while the instruments behind it stayed near room temperature. For an unshielded human, the limit is set long before heat — radiation and the solar wind become lethal well outside Mercury's orbit. Even at Earth's distance, unfiltered sunlight in vacuum will cause severe burns on the sunward side while the shaded side radiates heat away.

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 could you survive in the Mariana Trench? Unprotected, no measurable time at all — the pressure is over a thousand times atmospheric. In a submersible, as long as the life support lasts.
• 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 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.