Couper was born in Wallasey, Cheshire. She studied astrophysics at the University of Leicester and researched clusters of galaxies at the University of Oxford. After this, she was named senior planetarium lecturer at the Royal Observatory, Greenwich. She also hosted two TV series on Channel 4, "The Planets" and "The Stars". On radio, she presented the award-winning programme "Britain's Space Race" as well as the 30-part series "Cosmic Quest" for BBC Radio 4. She worked on the Millennium Commission, for which she was named a CBE in 2007. Asteroid is named in her honour.