SAN FRANCISCO — For a frigid hunk of rock and ice more than a billion kilometers away, Titan acts a lot like Earth. Lakes and seas that adorn Saturn’s largest moon may have formed in ways similar to ...

Lake Turkana in northern Kenya is often called the cradle of humankind. Home to some of the earliest hominids, its fossil-rich basin has helped scientists piece together the story of human evolution.

It’s right there in the name: “plate tectonics.” Geology’s organizing theory hinges on plates—thin, interlocking pieces of Earth’s rocky skin. Plates’ movements explain earthquakes, volcanoes, ...