What If the Earth Travelled Into The Sun?

What If the Earth Travelled into the Sun?

Few things are as certain as the Earth’s motion through space. Our planet travels around the sun, completing a full orbit every year, and the moon travels around the Earth, completing a full orbit roughly every month. But what if this wasn’t the case? What if some unknown force or object sent us careening straight for the centre of the solar system, our very own sun, which has a core temperature of 15 million degrees Celsius? While, for a short time, we’d get some nice warm weather, travelling into the sun ultimately spells inevitable doom for not just mankind, but every living creature and organism on the planet.

For the Earth to be launched towards its star, it’d first need to somehow fall out of the elliptical orbit it’s been enjoying for the last 4.5 billion years. Unfortunately for any doom-mongers out there, the Earth’s orbit has traditionally been very stable, as has the motion of all the celestial bodies we’re able to study. This isn’t to say that this couldn’t change; as we know, stars routinely die, and planets are destroyed throughout the entire universe.

In fact, one major theory as to how we could fall out of orbit relies on a sudden unpredictability in the way planets behave. There’s an idea that the orbits of certain planets could destabilise, sending them crashing into each other – for example, Earth could crash into its second-closest neighbour, Venus. There’s a less than 1% chance that the orbits of the planets would ever destabilise, though… and even if they did, there’s an even slimmer 1 in 2,500 chance of Earth and Venus actually crashing. Certainly, though, both Venus and Mercury would be on our way to the sun, if we ever did find ourselves headed in that direction. In which case, an interplanetary collision might be even more desirable than what would happen if we steamed straight into our solar centrepiece.

The good news is that, while cosmologists admit that a big enough force could knock the Earth out of orbit, such a force probably doesn’t exist. The Earth is travelling through space at around 67,000 miles per hour, so that it can complete its 584,000-million-mile journey around the sun in a suitably quick 365 days. In fact, we’re actually inching further and further away from the sun – but only by one millionth of a metre every year. It all means that the Earth’s momentum is so vast, it’d take an impossibly huge force to stop it from orbiting – and prompt it to fall towards the sun.

So, for the purposes of this hypothetical, we have to assume that a miraculous and unpredictable cosmic event has occurred which has caused the planet to simply stop moving. As Newton said, orbiting something is perpetually falling, but travelling fast enough to miss what you’re falling towards – and, in the Earth’s case, that’s the sun.

If we actually wanted to travel towards the sun, rather than spinning out of orbit and plunging into it by mistake, a few brave astronauts could feasibly make the journey. While our current technology would mean it’d be awfully slow to try and traverse those 93 million miles, it’s thought that astronauts in a specially designed ship could theoretically get within just 1.3 million miles before being cooked alive – although, they’d almost definitely die from exposure to cosmic rays approximately halfway into this journey…

The Earth, as a whole, would have just over two months to endure between the point orbit ceases and the point the planet reaches the sun. This is because if orbit stopped, the Earth would keep going at its 67,000 miles per hour, but gradually pick up speed as it gets closer to its star. So, Earth would get faster and faster and faster in its approach, meaning we’d all get hotter and hotter and hotter.

The planet’s average global temperature only has to rise by a few incremental degrees for our world to be rendered uninhabitable – as climatologists keep warning us. But, if we were sun-bound we’d soon see temperature gauges soar into the hundreds. The day-time temperature on Mercury’s surface, for example, is upward of 400 degrees – and the sun’s closest planet is still at least 28 million miles away from it. As with most of the major problems, it all rests on when Earth exits the Goldilocks Zone for life – an area in part dictated by how hot it is outside.

But, rising temperatures wouldn’t be the most immediate danger. It’d take around three weeks to really feel the heat, with average global temperatures rising by around 10 degrees – to match average equatorial figures. The first problem we’d face would feel even more fundamental. Because, at the point the Earth’s path changes, anything that isn’t actually attached to the planet’s surface would be sent flying because of the sudden sideways momentum. Gravity would keep us from being flung out of the actual atmosphere, but we’d still all be aimlessly hurtling around until we hit something – like bugs on a windshield.

But, more than just people and animals tossed into the air, this would also cause enormous tsunamis as all of the world’s oceans sloshed in one direction at once. Entire continents would be flooded without any chance of respite, within only a matter of hours – if not minutes. Depending on your position on Earth, you could also find yourself plunged into endless day or endless night, if the planet also stops rotating. The sudden shift would likely destroy the Earth’s magnetic sphere, too… So, we wouldn’t have any protection from solar radiation, right at the moment when we’d need that protection more than ever.

Say you have yourself a reliable shelter, though. The Indian summer of the first few days can only last so long. Within a couple of weeks, crops across the planet would start to die. Locations closest to the poles would be the last to become uninhabitable, but by the 35th day, the average temperature on Earth comes in at an incredible 60 degrees Celsius – breaking all previous records. Going outside would be totally impossible, not least because there wouldn’t be any shade because trees would now be burning up in vast forest fires. Extinction would be set in for all land mammals, including humans, as there’d be no real escape other than somehow relocating to the bottom of the sea or burrowing deep underground. But, even then, you’d have to be VERY deep underwater, because rising sea temperatures would soon start killing fish that live in the shallows. Even creatures that have specifically evolved to live in the extreme heat of places like the Sahara Desert would be dead just one month into our journey.

Earth reaches its next milestone one week later, as it crosses paths with Venus and officially leaves the Goldilocks Zone. At this point, only tardigrades, the most resilient living organism on Earth, are still alive. The planet’s surface temperature now exceeds 100 degrees, and the oceans are literally boiling – so, say you had hopped onto a submarine in a desperate bid to survive, here’s when your luck would definitely run out. After 50-55 days of sun-wards travel, even the tardigrades are dead, meaning that ‘life on Earth’ is now completely over. As our once lush and green – though now dry and fiery – planet propels toward the 60th day of its journey, it passes Mercury.

By now, because of the constant increase in speed, the temperatures skyrocket into brain-melting numbers. On the last day the planet has to live – roughly day 64 – we’re talking a rapid rise from 800 to 2,000 degrees Celsius. At this point, the floor really is lava, everything burns and any hope there might’ve been of anything surviving is long, long gone. But, it isn’t actually the ridiculous heat that finally ends the Earth. Instead, it’s the sun’s tidal forces, which are now powerful enough to tear the planet into pieces. So, the notion of Earth – or anything else – actually reaching the sun isn’t even possible… Because, before it gets to its solar goal, its entire structure is broken apart into nothingness. And, that’s what would happen if Earth travelled into the sun.