Saturn leads the Moon down the western sky this evening. The planet looks like a bright star just below the Moon. Venus, the much brighter “evening star,” is to their lower right at nightfall.

Saturn is best known for its beautiful rings. But it’s not the only “ringed” planet in the solar system. The three other giants also have rings. There’s also evidence that Mars had rings in the distant past. And Earth might have had rings, too – more than 450 million years ago.

Scientists looked at 21 impact craters that formed around that time. They used computer models that simulate the motions of Earth’s crust to learn the latitude of the craters when they formed. And they found that all the craters were fairly close to the equator. That suggests the space rocks that gouged the craters had a common origin.

From that and other evidence, the research team proposed that an asteroid several miles in diameter was captured into Earth orbit. The asteroid got so close to Earth that it was ripped apart by the planet’s gravity. The debris then formed a ring. But big chunks eventually fell to Earth. When they hit, they formed the craters that we see today.

Researchers also suggest that the ring could have “shaded” part of Earth. That could have caused the surface to cool – perhaps playing a role in creating the coldest ice age of the past half-billion years – a chill from our own beautiful ring.

More about falling space rocks tomorrow.

Script by Damond Benningfield