JANUS, the high-resolution camera on ESA’s JUICE mission, observed Earth during the August 2024 Lunar–Earth Gravity Assist. Images from a close flyby captured night- and day-side atmospheric phenomena, and a distant view resulted in a low-resolution Earth portrait. These observations validate JANUS performance and demonstrate the instrument’s capabilities. We focus our analysis on characterizing atmospheric systems that provide relevant examples for future studies of Jupiter’s atmosphere.