The planets in our solar system are remarkable and captivating objects for beginning astronomers to study. While merely observing the planets is fairly easy, it can be difficult to capture the high-quality images beginners hope for. The methods used for deep-sky astrophotography are optimized for dim, fairly large objects using large apertures and long exposure times. These tools do not work nearly as well for the planets, which have the reverse properties: they are bright and very small. As such, the planets can serve as great teaching tools for capturing astronomical images, using software processing tools, and understanding the role of angular size in a flat image. In this paper, we will explain how to implement “Lucky Imaging,” a simple but powerful process for photographing the planets. World-class facilities use Lucky Imaging in conjunction with adaptive optics, but we will show how you can achieve striking telescopic images with only a commonly available smartphone. We will show an example of how this tool can be combined with an image processing tool like PhotoShop to create imaginative images of what the planets might look like if Earth were in a different place. These tasks also enable the students to grapple with the implications of the fact that we perceive angular size rather than linear size.

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Linear distances on the focal plane are related to the angular size of objects in the field of view by the ratio of the image size to the focal length. A full-frame 24-mm width CMOS chip in a DSLR camera with a 40-mm lens would be able to encompass 24/40 of a radian, or roughly 33°.
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