Earth Had Rings Like Saturn Millions of Years Ago, Study Suggests

Astrophysics was once so crazy in love with Earth, it put a ring on it. But the engagement didn’t last, and the halo formation fell away.

While the Beyonce references are ours, the conclusion that our planet once had a ring system was reached by a trio of Earth scientists from Australia’s Monash University. In a new study, published in the journal Earth and Planetary Science Letters, they analyzed almost 500-million-year-old meteorite impact craters from around the world. They concluded that it was incredibly unlikely the alien bodies originated from an asteroid belt. Instead, they believe Earth once had a ring around it, chunks of which eventually rained down through the atmosphere—a discovery that could fundamentally alter how we think about the evolution of Earth’s climate.

It’s not as crazy as it might sound. Earth is actually notable for its lack of a ring system. Though Saturn’s rings are the most prominent, the researchers point out in the study that all of our solar system’s large planets have rings, though their composition varies. There’s also some evidence that Mars once had a ring of its own.

The impacts the scientists examined occurred during what’s known as the Ordovician, a geologic period that began 485 million years ago and lasted for almost 42 million years. During that time, Earth experienced an unusual number of meteorite strikes, 21 of which were examined for the study. The researchers looked at both the chemical composition of the craters, which showed a disproportionate amount of material that is often found in L chondrite meteorites. It’s a sign that the material came from meteorites resulting from a single asteroid breaking up.

They also looked at the locations of the craters. Meteorites tend to fall randomly, but the majority of the impacts were centralized within 30 degrees of the equator. That’s pretty tough to explain as happenstance, given that 70% of the Earth’s crust lies outside this area. They determined the chances of the impacts being random were minuscule, at just 1 in 25 million.

As for how the ring formed in the first place, they were obviously not constructed by an ancient alien race as a galactic defense against the Flood. Instead, it was the result of a near-impact with a very large asteroid 466 million years ago. The asteroid passed so close to Earth that its gravity caused it to disintegrate, leaving its debris to orbit the planet. Such an object would have had to cross Earth’s Roche limit, the critical distance where tidal forces overcome the asteroid’s structural integrity, causing it to break apart.

“Over millions of years, material from this ring gradually fell to Earth, creating the spike in meteorite impacts observed in the geological record,” said Andy Tomkins, a professor at Monash University’s School of Earth, Atmosphere and Environment, who led the study, in a press release. “We also see that layers in sedimentary rocks from this period contain extraordinary amounts of meteorite debris.”

If there was a ring around Earth, it would have had an enormous impact on the climate of the time. The material would have shaded the winter hemispheres and reflected light towards the summer hemispheres, leading to increased cooling in the former, and some slight increase to warming in the latter. As the meteorites fell to Earth, the dust they generated would also have contributed to cooling. This all, in turn, would have resulted in a major disruption to the chemical composition of the atmosphere, including CO2 levels.

“The idea that a ring system could have influenced global temperatures adds a new layer of complexity to our understanding of how extra-terrestrial events may have shaped Earth’s climate,” said Tomkins.

There wouldn’t have been much life, if any, capable of appreciating the halo overhead. Life on Earth at the time was mostly aquatic, including primitive fish, cephalopods, corals, and early vertebrates. Land was largely barren, with only simple plants like mosses beginning to emerge.

While Tomkins and his colleagues paint a compelling picture for their theory, there are some issues they acknowledge still need to be resolved. Dating techniques show the craters that were studied mostly fell into two separate eras. To explain why they didn’t fall at around the same time, the scientists said it’s possible some of the debris formed a mini-moon, which also eventually crumbled under the force of Earth’s gravity. They also admit that more study is needed on the geology of sedimentary rocks near the equator to verify their hypothesis.

While more work clearly needs to be done, the theory is believable and just goes to show Earth is even more of a survivor than we thought. As the meteorites fell, our planet was definitely jumpin’, jumpin’.