Moeraki Boulders at sunset, South Island, New Zealand

© Douglas Pearson/eStock Phot

Rocks and rollers. Moeraki Boulders, South Island, New Zealand

Are you ready to rock the new year? Today is Old Rock Day, a day for celebrating and learning about old rocks and fossils. Rocks are common and few of us take the time to consider how amazing they are. But forged in volcanoes or molded by millennia of pressure, these solid masses of minerals hold the key to understanding how our planet formed. Rocks can also contain fossils, the remnants of long-extinct organisms, which give scientists clues about what creatures and plants have lived on Earth during its 4.5-billion-year history.