A cup of hot coffee put in refrigerator cools down instantly. Similarly, if the sun was suddenly “switched off”, which in reality is physically impossible, the Earth, compared with the surrounding space, would remain hot for several million years after that. However, the inhabitants of our planet would feel the cold much earlier.
Within a week, the average global temperature of the surface would drop to 17° Celsius, and within a year – down to 40° C below zero. The upper layers of the oceans would freeze, but the ice would keep the water in the depths of the oceans warm and would prevent freezing for hundreds of thousands of years.
“Millions of years after, the Earth would reach a stable temperature of minus 160° C, when the heat from the planet’s core would be equal to the heat it radiates into space,” explains Professor of Planetary Sciences at Caltech David Stevenson.
And although some microorganisms that live in the earth’s crust could survive, life on earth would stop very quickly. Photosynthesis would stop immediately, so most of the plants would die in a few weeks. However, large trees could live for several decades due to a slower metabolism and substantial reserves of sucrose.
People could stay in submarines in the deep and warm parts of the ocean, but a nuclear and geothermal habitat would be a more attractive option. Iceland would be the best place to stay in such a situation. Its population now heats 87% of their homes using geothermal energy, and, according to a professor of astronomy at the University of Rochester Eric Blackman, people could use the volcanic heat for hundreds of years.
Certainly, the Sun not only heats the Earth, but also keeps it in orbit. If its mass suddenly disappeared, which in principle is impossible, then our planet would just fly like a balloon inflated to the limit and sharply released from one’s hands.