Herschel is a 304 kilometer

impact crater An impact crater is a circular depression in the surface of a solid astronomical object formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact crater ...

in the Martian southern hemisphere, at 14.5°S, 130°E, located in the Mare Tyrrhenum region of

Mars Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury. In the English language, Mars is named for the Roman god of war. Mars is a terrestrial planet with a thin at ...

. The crater is jointly named after the seventeenth/eighteenth century father and son

astronomer An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, moons, comets and galaxies – in either ...

William Herschel Frederick William Herschel (; german: Friedrich Wilhelm Herschel; 15 November 1738 – 25 August 1822) was a German-born British astronomer and composer. He frequently collaborated with his younger sister and fellow astronomer Caroline ...

and John Herschel. PSP 002860 1650 RED

Moving Sand Dunes

Mars Global Surveyor ''Mars Global Surveyor'' (MGS) was an American robotic space probe developed by NASA's Jet Propulsion Laboratory and launched November 1996. MGS was a global mapping mission that examined the entire planet, from the ionosphere down through t ...

spacecraft originally photographed fields of dark sand dunes within Herschel. Images from the

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the US federal government responsible for the civil List of government space agencies, space program ...

Mars Reconnaissance Orbiter ''Mars Reconnaissance Orbiter'' (MRO) is a spacecraft designed to study the geology and climate of Mars, provide reconnaissance of future landing sites, and relay data from surface missions back to Earth. It was launched on August 12, 2005, an ...

showed that sand dunes on the floor of the Herschel crater are not stationary (as previously believed), but moved over time. Images from photos taken by the Orbiter's

High Resolution Imaging Science Experiment High Resolution Imaging Science Experiment is a camera on board the ''Mars Reconnaissance Orbiter'' which has been orbiting and studying Mars since 2006. The 65 kg (143 lb), US$40 million instrument was built under the direction o ...

(HiRISE) on March 3, 2007 and December 1, 2010 show clear shifting of dunes and ripples. Research published in Icarus stated that the dunes in Hershel Crater moved 0.8 m in a time span of 3.7 Earth-years. Also, it was determined that dune ripple moved 1.1 m in that time period.Cardinale, M., S. Silvestro, D. Vazd, T. Michaels, M. Bourke, G. Komatsu, L. Marinangeli. 2016. Present-day aeolian activity in Herschel Crater, Mars. Icarus: 265, 139-148.

Moving Sand Dunes

References

See also