Bernard Quatermass
Professor Bernard Quatermass was a British scientist. Whether he was real or fictional was unclear.
He was implied to have worked alongside Dr. Rachel Jensen in the British Rocket Group (DW: Remembrance of the Daleks). In 1997, paranoid and full of bleak pessimism, he possibly appeared on television with Dr. Patrick Moore in a panel discussion regarding the possibility of life on the planet Mars. (NA: The Dying Days)
UNIT scientific advisor Professor Malcolm Taylor named a unit of measurement after Bernard Quatermass, but Taylor might have been talking about a television character, not a real man. (DW: Planet of the Dead)
Behind the Scenes
Background
Quatermass and the British Rocket Group had originally appeared as the protagonist of a series of four horror-science fiction television serials written by Nigel Kneale. The first three aired during the 1950s on the BBC. (The last serial simply entitled Quatermass aired in 1979, though not on the BBC.) These would have great influence onDoctor Who serials as The Web of Fear and Image of the Fendhal, to name only two. The Lazarus Experiment all but re-made the first Quatermass story.
For his part, the creator of Bernard Quatermass, Nigel Kneale, was on record as having hated Doctor Who, and refused to write for the programme when invited.
Quatermass also inspired the Nightshade, a television serial in the Doctor Who Universe.
In 2005, the BBC aired a remake of one of the original serials, The Quatermass Experiment. Appearing in the serial were David Tennant and Indira Varma prior to their involvement as the Tenth Doctor and Suzie Costello, respectively. Mark Gatiss, longtime performer and writer of Doctor Who spinoff productions, scriptwriter for the new series, and later a guest star in The Lazarus Experiment, also appears in the production.
Canonicity of the character
Whether or not Bernard Quatermass is a real person in the Doctor Who Universe is very much a matter of opinion. At no point in any piece of Doctor Who fiction was any character referred to as "Professor Bernard Quatermass". In The Dying Days, a character is announced midway through a sentence as "-ermass" and then subsequently "Professsor" and "Bernard" are used to refer to him. In Remembrance of the Daleks, his last name is never uttered. And in ''Planet of the Dead, Malcolm Taylor delivers his line in such a way that "Quatermass" could be read as Quatermass — that is, he could be referring to the television show as much as a real person.
In the Doctor Who Universe, the Nightshade serials (NA: Nightshade) have many similarities with the Quatermass serials. It is possible to assume that because Bernard Quatermass is real, Nightshade effectively replaces Quatermass in the Doctor Who Universe. It's also equally possible to believe that Nightshade is just a copy of the existing show, Quatermass, as there are many real life instances of two television programmes sharing multiple commonalities.
A number of actors portrayed the character, with none considered "definitive", however Lance Parkin has said that he meant to visualized the elderly, nearly crazed John Mills version from the fourth and final Quatermass serial as the one who appeared in the New Adventures novel The Dying Days.
