By Tyler MacDonald WATCH RELATED VIDEO Submit After analyzing the oxygen isotope levels in rocks from the Earth and the moon, the scientists concluded that the moon was the result of a head-on collision with the forming planet Theia. Advertisement © 2017 HNGN, All rights reserved. Do not reproduce without permission. Advertisement 0 COMMENTS CLOSE COMMENT Get HNGN's Top Stories Newsletter Everyweek You have already subscribed. Thank you.