A film about the 1960s fear that the Moon would bring back a plague — and about what NASA said in public against what it weighed in private.
In the 1960s, as NASA prepared to land people on the Moon, serious scientists argued that microbial life might have evolved on the lunar surface — and that if it came back with the astronauts it could contaminate the biosphere and cause a plague worse than any in human history. A network of scientists, officials and civil servants built a quarantine protocol to contain that possibility.
Degroot went through what actually happened, and found that what NASA said in public and what it weighed in private ran the other way from each other — and that the protocol was riddled with failures, many of them never disclosed.
What makes it a serious piece of history rather than a scandal is the conclusion. Nobody was corrupt. The probability really was low. The astronauts were three known, present human beings and the Earth’s risk was theoretical and unprecedented. This is what a rational risk calculus produces — which is exactly why it is worth understanding.
We wanted the film to be about the people, not the procedure — the public and what the public believed, the scientists who speculated, and the officials who had to make the call and absorb the criticism. As Degroot puts it, they gambled the fate of the Earth. So the film shows the Earth, and it shows a great many people, and it stays away from the technical apparatus entirely.
The whole middle of the film is one unbroken chain of transformations, and it carries the argument by itself: the boundary between what was contained and what was told became a broadcast, and then background noise in the room where the decision was made. The stills below follow that chain.

He lets a toy spaceship go and it changes mid-flight — the plastic seams dissolve, fire appears, and by the top of the frame it is a real rocket. The film sets its scale in twenty seconds without a word: the thing that looked like a game was a wager on the biosphere.

The film gives the fear a shape — a bloom of blue spheres — and lets it move across the world.

Scientists, officials and civil servants ringed around the Moon, every thread converging on it. Look at the colour: the field is already split, cool on one side and warm on the other. The public story and the private one are in the same picture before anyone separates them.

The quarantine window becomes a television, the television reaches every living room, and then the same set is playing in the corner of the room where the decision is being made — with nobody watching it. The one real photograph in the whole film sits inside that screen: Armstrong, Aldrin and Collins behind the quarantine glass on the deck of the USS Hornet, with Nixon at the microphone outside.

The public assurance on one pan, the private arithmetic on the other: three known, present people weighed against an unlikely but unlimited risk to Earth. Not villainy: arithmetic.

The film ends by refusing the catastrophe it spent two minutes building. The world the scientists feared to lose is still standing — tree, wheat, city, fish, bird, person. Not a triumph, just still there. The fear was real; the catastrophe was not. And then the boy walks back in, sets the world down, and gives it its weight.
Dagomar Degroot is a historian of environmental change on Earth and across the solar system, and Associate Professor of Environmental History at Georgetown University. The Dan David Prize selection committee was “impressed with Degroot’s highly innovative and timely research on climate history, that provides a novel emphasis on societal adaptation and survival under extreme conditions and successfully integrates insights from the humanities and the sciences, as well as by his commitment to conveying this work to the broader public.”
Each year the Foundation chooses, with the laureate, the subject of the film they are honoured for, and we turn it into script, image and motion. The laureate sees it for the first time on the evening of the prize — on the big screen, in a room full of people who have come to honour them. Afterwards the films go out on social media, YouTube, Facebook, LinkedIn and more, and on the Foundation’s own site, beside the committee’s reasoning and the laureate’s interview, and some laureates carry them into their own classrooms, to show what it is they work on.