“Mars does not have an atmosphere and does not have a magnetic field today, so the planet doesn't have the protection from radiation that our atmosphere and magnetic fields provide us on Earth.”

American astrobiologist

David H. Grinspoon is an American astrobiologist. He served as Senior Scientist for Astrobiology Strategy at NASA from 2023 to 2025, and earlier held the inaugural Baruch S. Blumberg NASA, Library of Congress Chair in Astrobiology in 2012 to 2013. He is known for work at the intersection of astrobiology and NASA strategy, with roles that connect scientific research and public scholarship. His writing and public remarks often reflect that field, though the facts here identify him mainly through his scientific appointments.