A study published last month in the journal Nature found that two “blobs of unusual material” near the center of the earth could be remnants of an ancient planet that collided with Earth billions of years ago in the same impact that created the moon. The “blobs,” or large low-velocity provinces, were discovered in the 1980s. Still, geophysicists didn’t know what they were but had long-hypothesized they were remnants of an ancient, smaller planet called Theia. One of the study's authors, Dr. Paul Asimow, a professor of geology and geochemistry at Cal Tech University, joined the show this week to discuss the findings and disprove the "Hollow Earth" theory.