This changes everything," Steve Desch, an astrophysicist and professor in the School of Earth and Space Exploration at Arizona State University, who was not involved in the study, told Live Science. "The debate about the origins of Earth's water has centered for decades on whether Earth got its water from comets or chondrites (rocky meteorites)," he said. This study suggests that dust and gas around the sun was an important contributor as well, calling for re-evaluation of earlier conclusions that overlooked the role of material within the so-called solar nebula.