Imagine an enormous football stranded in the Solar System. I mean, the Earth shaped like one.
What could cause our planet to change its shape so drastically? And what would it mean for all the life inhabiting it?
If you thought the Earth was round, you weren’t exactly right. And if, by any chance, you thought it was flat, you were definitely wrong. The true shape of Earth is called an oblate spheroid. It’s a sphere that’s squashed at the poles so that the equator sticks out a bit.
Although most planets are oblate spheroids, there are some oddly shaped cosmic objects out there. One of Saturn’s moons, Prometheus, for one, resembles a potato. And this comet looks like a rubber duck.
And then there’s an exoplanet shaped exactly like an American football. Imagine if that was our Earth shaped like that.
It wouldn’t be good for us. That football-shaped planet is called WASP-121b. And the reason why it has a shape like that is its very close proximity to its star.
The gravitational tidal forces of that star affect the planet unevenly, stretching it at the equator. And because the star and the planet are so close, the planet’s upper atmosphere reaches 2,500°C (4,200°F). That’s roughly half the temperature of our Sun.
WASP-121b is ridiculously hot. You definitely wouldn’t want Earth to switch places with it. But how about we move our planet closer to our Sun? Would that be enough to reshape the Earth like that?
Earth orbits the Sun at a safe distance of 150 million km (93 million mi). Scientists call this distance one astronomical unit, or AU.
Move the Earth a few million kilometers closer, and it would get very hot on the planet. For example, if we moved our planet into the orbit of Venus, the Sun would be hitting us with 92% more solar energy.
The Earth wouldn’t get scorching hot immediately. First, the increased brightness would cause a runaway greenhouse effect. All our glaciers would melt, and poison our atmosphere with elevated methane levels.
The sea levels would rise, and force people to relocate from the flooded coasts. The increased sea area would cause even more heat absorption, raising the temperature of the oceans even more.
As the greenhouse gases were building up, our planet would be heating up to temperatures of Venus. We’re talking surface temperatures as high as 462°C (864°F). As you might guess, no life could ever inhabit a planet that hot.
But what if the Earth got to keep the shape of a football, minus the extreme heat? Then life would still go on, but it would be a little different. For one thing, the Earth might have to rotate faster in order to keep that shape. A day on Earth might become as short as only a few hours.
Secondly, gravity wouldn’t be distributed evenly throughout the planet. The poles would have lower gravity, while gravitational pull at the equator would be stronger. This is because there’d be more mass around the equator.
Other than that, life would go on. We’d just keep inhabiting a football-shaped planet. And maybe it would solve that age-old argument between the Brits and the Yanks on whose football is better.
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- “Hubble Uncovers a ‘Heavy Metal’ Exoplanet Shaped Like a Football”. 2020. NASA.
- “Strange But True: Earth Is Not Round”. Choi, Charles. 2007. Scientific American.
- “Why are planets all the same shape?”. Kate Baggaley, 2020. Popular Science.
- “How Hot Is The Sun?”. Sharp, Tim. 2017. space.com.
- “The Effects Of Melting Ice Glaciers – Help Save Nature”. 2007. Help Save Nature.
- “How Far Away Is Venus?”. Redd, Nola. 2012. space.com.
- “How Far Is Earth From The Sun?”. Sharp, Tim. 2017. space.com.