Caerols, H., & Asenjo, F. A. (2020). Estimating the MoontoEarth Radius Ratio with a Smartphone, a Telescope, and an Eclipse. Phys. Teach., 58(7), 497–501.
Abstract: From ancient times, the different features of planets and moons have created a huge interest. Aristarchus was one of the first to study the relative relations among Earth, Moon, and Sun. This interest has remained until today, and therefore it is always relevant to make this knowledge more appealing to the younger generations. Nowadays, smartphone technology has become an important tool to teach physics, and this gives us a huge opportunity to bring science closer to students in a simpler manner. In this work, we show how simple photographs of a partial lunar eclipse are sufficiently good to estimate the ratio between the Moon and Earth radii. After taking the photographs, the procedure for the calculation is straightforward and it can be reproduced easily in a one–hour class

Caerols, H., Carrasco, R. A., & Asenjo, F. A. (2021). Using smartphone photographs of the Moon to acquaint students with nonEuclidean geometry. Am. J. Phys., 89(12), 1079.
Abstract: NonEuclidean geometry can be taught to students using astronomical images. By using photographs o the Moon taken with a smartphone through a simple telescope, we were able to introduce these concepts to highschool students and lowerlevel college students. We teach students how to calculate lengths of mountain ranges or areas of craters on the Moon's surface and introduce ideas of geodesics and spherical triangles. Students can see that accurate measurements cannot be
obtained using at geometry. Instead, by using three{dimensional curved geometry, estimates of lengths and areas can be computed with less than 4% error.
