By Stephanie Pappas
A strange slab of rock discovered in Russia more than 20 years ago appears to be a combination sundial and moondial from the Bronze Age, a new study finds.
The slab is marked with round divots arranged in a circle, and an astronomical analysis suggests that these markings coincide with heavenly events, including sunrises and moonrises.
The sundial might be “evidence of attempts of ancient researchers to understand patterns of apparent motion of luminaries and the nature of time,” study researcher Larisa Vodolazhskaya of the Archaeoastronomical Research Center at Southern Federal University in Russia told Live Science in an email.