The moon in the smartphone

At our observatory, clever young astronomers appear again and again, who have techniques that the old hands do not have on their screen. One of these colleagues has now shown us what he can do with his smartphone. Jannis Lauff from the Waldbröl Comprehensive School had borrowed one of our Newtonian telescopes from the school observatory. He bought a cell phone holder for it and now delivered pictures of the moon, which he made in the last full moon phase at home. He achieved a magnification of 36x at a telescope focal length of 900mm with a projection through a 25mm eyepiece (900mm / 25mm = 36). In doing so, he only had to expose for 1/160-second. The image is “upside down” because of the telescope optics. Remarkably, the image is not only sharp but shows well-known but for the eye invisible formations. Especially the crater Tycho at the upper lunar rim is to be emphasized, whose impact rays reach into the dark Mare Nubium.