ESA's Mars Express has provided images of a remarkable crater on Mars that may show evidence that the planet underwent significant periodic fluctuations in its climate due to changes in its rotation axis. On 19 June 2011, Mars Express pointed its high-resolution stereo camera at the Arabia Terra region of Mars, imaging the Danielson and Kalocsa craters. Danielson crater is named after the late George E Danielson, who was instrumental in the development of many spacecraft cameras flown to Mars. Seen to the right (north) in the image, it is the larger crater, roughly 60 km across.