Mars explorers have detected what they call a “periodic signal” in the ancient rock of the Red Planet: a 10-layer pattern that repeats at least 10 times. Studying the stair-step formations of Becquerel crater and other craters in the Arabia Terra region reveals that climate cycles over eons on ancient Mars left rhythmic patterns in sedimentary rock layers.
The rhythm seems to correlate to a known 10-to-one pattern of wobbles in the tilt of the planet’s rotation axis. Each wobble seems to have changed the climate enough to alter how sedimentary rock was laid down. Scientists find similar patterns on Earth.