He is the science correspondent for the PBS News Hour, a producer, director, writer and correspondent for the PBS documentary programs NOVA and FRONTLINE and an aviation analyst for CNN. He owns MOBIAS Media, Inc., a production company that creates award winning documentary films primarily for PBS as well as several educational and corporate clients.

For nearly seventeen of his thirty-nine years in the news business, he was a staff correspondent and anchor with CNN, based in Atlanta and New York. He served as the science, environment and aerospace correspondent and the anchor of various programs, including American Morning.

While at CNN, O’Brien secured a deal with NASA to become the first journalist to fly on the space shuttle. The project ended with the loss of Columbia and her crew in 2003 – a story he told to the world in a critically acclaimed sixteen-hour marathon of live coverage. He later served for ten years as a member of the NASA Advisory Council, offering strategic advice to the NASA administrator.

Prior to joining CNN, he worked as a reporter at television stations in St. Joseph, MO, Albany, NY, Tampa, FL and Boston. He began his television career as a desk assistant at WRC-TV in Washington, DC.

O’Brien is an accomplished pilot and is frequently called upon to explain the world of aviation to a mass audience.

He has won numerous awards over the years, including six Emmys, a Peabody and a DuPont.

He has produced, written and directed nine films for PBS NOVA: Mind of a Rampage Killer (2013), Manhunt Boston Bombers (2013), Megastorm Aftermath (2013), Why Planes Vanish (2014), Nuclear Meltdown Disaster (2015), Fifteen Years of Terror (2016), The Nuclear Option (2017), Inside the Megafire (2019) and The Great Electric Airplane Race (2021).

He also produced, wrote and directed FRONTLINE Coronavirus Pandemic (2020) and was a writer and correspondent for four FRONTLINES: Flying Cheap (2010), Flying Cheaper (2011), Nuclear Aftershocks (2012) and Dollars and Dentists (2012).

In February of 2014, a heavy equipment case fell on his forearm while he was on assignment. He developed Acute Compartment Syndrome, which necessitated the emergency amputation of his left arm above the elbow. Despite the loss of his arm, he has completed two marathons, several ultra-distance bike rides, a half Ironman, and has returned to flying airplanes.

Born in Detroit and raised in Grosse Pointe Farms, MI, he is based in Vero Beach, Florida. He was a history major at Georgetown University. Miles has two grown children. His son is a US Navy Lieutenant stationed in Catania, Italy and his daughter is a social worker in New York City.