3 ms·
Why does the Earth have one billion years left?
by ezequiel-garzon 9y ago
Why does the Earth have one billion years left?
- Banthum 9y agoIn about a billion years the sun will exhaust enough nuclear fuel to cool and expand, boiling the oceans, blowing off our atmosphere, and turning Earth back into a sterile rock. It's predicted by astronomers and physicists who study stellar evolution.
- antisthenes 9y agoNo, that doesn't happen until 5 billion years into the future. The Sun will gradually keep getting hotter and slightly more luminous up to that point. Earth will be a desert long before the Sun exhausts nuclear fuel to start expanding and becoming a red giant.
- maze-le 9y agoAll stars become gradually hotter the older they get. G-type stars like our sun are no exception to this. On a certain point in time (currently estimated at 1Gy from now), the energy output of our sun is so big, that the Carbonate–silicate cycle[0] cannot continue uninterrupted. Thus CO2 and CO cannot be absorbed by the geosphere. The breaking of this process will gradually enrich the atmosphere with CO2, leading to a runaway greenhouse effect (a bit like on Venus). But I would not worry about that. It took 500My for life to evolve from trilobites to humans. This timespan is twice as long... [0]: https://en.wikipedia.org/wiki/Carbonate%E2%80%93silicate_cycle https://en.wikipedia.org/wiki/Carbonate%E2%80%93silicate_cyc...