Space and Physics
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It is Terrifying Affair Thursday, and we are imagining a scenario that could never happen, but is wonderfully fun to explore. And in case it becomes a ridiculous conspiracy theory like Earth losing gravity for 7 seconds, at least we are ahead of the curve in debunking it. The scenario for the day is what if the Sun somehow disappears? Magically vanishes from the center of the Solar System. What would happen next?
The rest of this article is behind a paywall. Please sign in or subscribe to access the full content.Well, for the first 8 minutes and 20 seconds, literally nothing would happen. We wouldn’t even know it’s gone, and our planet wouldn’t feel it. That's because the Sun is about 150 million kilometers (around 93 million miles) away, and 8 minutes and 20 seconds is the time it takes for both its light and gravity to reach us.
Light and gravity both move with the same speed – the speed of light, or 300,000 kilometers (186,000 miles) per second – in a vacuum, something that was suspected for a long time and finally confirmed by the detection of gravitational waves. We wouldn't notice anything was wrong at first because we are always looking at the Sun as it existed just over 8 minutes ago. Which means we'd still be traveling around the spot it used to be for 8 minutes, too.
After we realize the Sun is gone, things would go bad pretty quickly. Yet, maybe not as quickly as you might imagine.
Both hemispheres would be in darkness, and our planet would go off on a literal tangent, a mostly straight line from the last place it felt the gravity of the Sun. You might think there will be chaos, what with seven other planets also losing their star, but every Solar System body would begin moving in a straight line, and they are extremely unlikely to cross. Planets are pretty far away from each other, despite what pictures of the Solar System show.
One possibility for chaos is Jupiter (it's always Jupiter). The Sun contains most of the mass in the Solar System – a whopping 99.86 percent – but the king of the planets holds the next biggest fraction. Big enough to technically not orbit the Sun at all. The Sun and Jupiter's gravitational dance keeps plenty of asteroids in certain regions; without the Sun, these would be disrupted in quite creative ways that could bring about collisions.
In general, though, collisional scenarios are very unlikely. Anyway, we have bigger worries on Earth. It would be a matter of days before the surface temperature plummets below zero. With some optimistic approximation, we'd get about 20 days before the average surface temperature is at the freezing point of water.
In that time, most plants and animals would have died off, either directly from the lack of sunlight and drop in temperature or due to the death of their food source. Humans would also start dying in the millions. Temperatures would continue to plummet, eventually reaching a temperature similar to what’s measured on Pluto today, just tens of degrees above absolute zero.
Is this the end for life on Earth? Not necessarily. The deep ocean might remain liquid for a long time, and our planet’s internal heat would be sufficient for the organisms thriving in the proximity of deep oceanic vents.
Humans, too, might have a chance to survive. While life in submarines is certainly a possibility, the best chance for humanity to survive is Iceland. The country already uses geothermal energy for a large fraction of its current use, so it could step it up as the rest of us die frozen and in the dark.
But seeing as we have been consuming the planet's natural resources at a rate that far exceeds its capacity to renew them for a number of years now, sorry, there's likely no happy ending with this one!
