This picture of a crater resembling a "happy face" was acquired by the Context Camera (CTX) on Mars Reconnaissance Orbiter on January 28, 2008. The unnamed crater is about 3 kilometers (1.9 miles) across. It is located among the Nereidum Montes, north of the Argyre basin, near 45.1°S, 55.0°W. North is toward the right and sunlight illuminates the scene from the upper right. Credit: NASA / JPL / MSSS
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Apparently Mars is dotted with this kind of graffiti. Here are pictures of two more Martian happy faces.
