In 1983, an unseen comet struck the rings of Saturn. Almost a decade later, a comet collided with Jupiter. These events tilted and left residual ripple patterns in the rings of both planets, according to a pair of papers in Science that piece together a planetary puzzle.
Published online at ScienceExpress, the studies indicate that a planet’s rings can act like a giant record, preserving the effect of every passing comet. Studying the subtle spiral patterns these comets leave behind allows scientists to play back the history of impacts years and even decades later.