A probe was sent on its long mission to the new planet to conduct experiments along the way to assist the teams in determining as much as they are able before a manned mission is undertaken. The probe, Aeneas I, along with powerful earth-based telescopes provided some early images of Artemis. though they revealed not surface detail, they did allow the teams to determine the diameter of the planet.

Using the small angle formula coupled with the known distance, the diameter was found by the teams to be 1,326 miles. For a planet this is small, very small as we see in the list of diameters below.