Scientists may have overestimated how old Saturn's rings and moons are—by more than 4 billion years. In fact, the planet's rings and many of its 62 moons likely didn't form until dinosaurs were around to see it happen, Discovery reports. Researchers from the SETI Institute measured changes in the orbits of Saturn's moons and rings—caused by the tidal forces they constantly exert on each other—to create a computer model capable of mapping their histories, according to a press release. They figured out the orbits of the icy moons closer to the planet hadn't changed as much as would be expected had they formed along with the planet 4.5 billion years ago as previously believed. Conversely, the planet's rings were shifting too quickly to be that old.
Instead, it's likely the moons and rings were created in the most recent 2% of Saturn's history—or about 100 million years ago—when older moons circling the planet crashed into each other. Dinosaurs roamed the Earth from about 230 million years ago to 66 million years ago, CNN reports. Researchers published their findings Thursday in the Astrophysics Journal. They hope to use them to figure out the ages of other moons in the Solar System. "It’s pretty crazy to think that moons were forming in our Solar System during a time on Earth that many of us can actually envision," Science Alert states. "Cosmically speaking, it's like it only happened yesterday." (NASA is baffled by red arcs on one of Saturn's moons.)