Two generations after Ernst Haeckel’s seminal biological art, American artist Irving Geis (October 18, 1908–July 22, 1997) ushered in a new era of scientific illustration, his intricate hand-drawn work shedding light on such landmark twentieth-century discoveries as the structure of proteins and DNA. When he was only 29, he was commissioned by Fortune to create this stunning drawing of the circulatory system, which would come to influence a wealth of subsequent stunning vintage illustrations of the body and which marked his foray into scientific illustration:

Though best-remembered today as the illustrator behind the 1954 classic How to Lie with Statistics (which remains an essential piece of cultural literacy, all the more relevant in today’s data-driven everything), Geis found himself mesmerized by the world of science by the beginning of the 1960s — a world that had been catapulted into an electrifying renaissance with the discovery of DNA only a few years earlier. And so Geis, formally trained as an architect and thus as far removed from science as formal education makes possible, set out to illuminate the building blocks of life using his singular skill. Soon, he began working with Scientific American and illustrating everything from cellular biology to space travel.

In 1960, a year before he created his now-legendary myoglobin illustration for Scientific American, Geis was commissioned by the magazine to draw a series of diagrams envisioning four alternative flight paths to Venus. An article titled “Interplanetary Navigation,” premised on the idea that space flight between the planets should be a reality “within a year or two,” imagined how an earth-bound navigator would go about bringing a vehicle loaded with scientific instruments to the alluring second planet from the sun, which Scientific American deemed “the planet most likely to be visited first by an interplanetary vehicle.” (They were, of course, wrong — it wasn’t Venus, and it took another ten years to realize the interplanetary dream with Mars.)

Geis’s first task was to revise our conventional models of the cosmos with a third dimension in mind, because treating the solar system as two-dimensional “could cause a vehicle to miss its objective by a thousand miles.” So Geis took the standard two-dimensional diagram…

…and gave it a third dimension, drawing Earth’s orbit on one transparent sheet of plastic and Venus’s on another, then mounting the two sheets in a glass plate and angling them at the approximate angle at which the two planets’ orbital planes intersect each other:

Geis then inspected his three-dimensional model and decided on the best angle at which to translate it into a two-dimensional diagram. The resulting four diagrams depicted the four possible paths to Venus:

Complement Geis’s work with this retrospective of 2,000 years of scientific images and a look at the history of medical illustration.