For over 150 years, geologists have debated how and when one of the most dramatic features on our planet—the Grand Canyon—was formed. New data unearthed by researchers at the California Institute of Technology (Caltech) builds support for the idea that conventional models, which say the enormous ravine is 5 to 6 million years old, are way off.

Caltech geology graduate student Katie Stack says her Caltech experience has provided her with the best of both worlds. Literally. As one of five Caltech graduate students currently staffing the Mars Science Laboratory mission, Stack is simultaneously exploring the geologic pasts of both Mars and Earth. She and her student colleagues apply their knowledge of Earth's history and environment—gleaned from Caltech classes and field sites across the globe—to the analysis of Curiosity's discoveries as well as the hunt for evidence of past life on the Red Planet.

Andrew Ingersoll, Earle C. Anthony Professor of Planetary Sciences, has been a leader in the investigation of planetary weather and climate for nearly five decades.