Ever since the sun was born around 4.6 billion years ago, the solar system has been a violent place. Like a pinball machine filled to the brim, our cosmic neighborhood was once packed with meteors, comets, and even baby planets crashing into each other, leaving scars in the form of impact craters.

Today, we know that space rocks of all shapes and sizes continue their jostling dance. But it’s not clear how the number of impacts has actually changed over time.

Now, researchers using data from a NASA moon probe report something startling in the journal Science: 290 million years ago, the rate of impacts on the moon—and thus, Earth—increased dramatically, and that onslaught has possibly not yet died down.

This