Overall, Earth’s pretty good. If you take humans out of the equation, it’s a great place to raise a family — of lemurs, wallabies, or any animal, really. But what if our terrestrial home were a little more like one of the gas giants? Apropos of nothing, what if Earth had rings? Some very smart scientists tell Inverse the answer is unsurprisingly complex.
According to astronomer Edward Guinan, who is credited with discovering Neptune’s ring system back in 1982, the first thing worth noting is that Earth did in fact have rings long ago.
“About 4.4 to 4.5 billion ago when the Earth likely collided with another body (near the size of Mars, sometimes called Theia), it almost tore the Earth apart,” Guinan explains. “The debris ejected from the event orbited the Earth, and via collisions and gravity eventually formed the Moon. This is called the ‘Big Splat’…[and] at the time the Earth would have had a dense ring system.”
Obviously there’s no way to determine exactly what that ring system looked like. It probably wasn’t as extensive as Saturn’s, since we’re a smaller planet with a smaller gravity field. Still, our rings probably played an important role in our early history.
One idea is that from these rings of debris, at least two bodies formed — the makings of what would be Earth’s moon and a smaller moon, which eventually collided with the proto-moon.
“These secondary collisions explain the difference in cratering and internal mass distribution between the two hemispheres of the Moon,” Guinan says.
Artist's rendition of early Earth. (Image: NASA/Simone Marchi)
But let’s just say we all lived in an ideal universe and that Earth had a ring system right now. Caitlin Ahrens, an astronomer at the University of Arkansas, says we’d literally be living in space utopia — and hell — at the same time.
“If we did have a large ring system, our views would be spectacular,” she says. “Our moon could cause rippling in our rings because of our tidal lock, and rippling could lead to snowballing more moons. [It could also] push material out of gravitational hold and fall to Earth. So we would be in more danger of falling objects.”
A ring system would also have implications for our weather, depending on the thickness of said rings. Ahrens says thick rings could effect local sunlight, which wouldn’t be great for farmers.
Even in a hypothetical scenario, Earth’s rings couldn’t outshine Saturn’s — literally.
“The composition of [Earth’s] rings would be different,” Ahrens explains. “Most of Saturn’s are rock and ice. Ice would not survive where we are in the Solar System so most of our rings would be iron and dust based. Our rings would be dark for sure.”
Saturn and its rings, taken by NASA's Cassini spacecraft back in 2011. Show off.
So while nothing can compare to Saturn’s and its illustrious rings — even in a completely hypothetical universe — it’s nice to imagine Earth tuggin’ around some space debris. That said, maybe it’s best we don’t live in constant fear of random objects raining down on us.
