The Nördlinger Ries is an impact crater and large circular depression in western Bavaria and eastern Baden-Württemberg. It is located north of the Danube in the district of Donau-Ries. The city of Nördlingen is located within the depression, about south-west of its centre. Etymology "Ries" is derived from Raetia, since the tribe of Raetians lived in the area in pre-Roman times. Description The depression is a meteorite impact crater formed 14.808 ± 0.038 million years ago in the Miocene. The crater is most commonly referred to simply as Ries crater or the Ries. The original crater rim had an estimated diameter of . The present floor of the depression is about below the eroded remains of the rim. It was originally assumed that the Ries was of volcanic origin. In 1960 Eugene Shoemaker and Edward C. T. Chao showed that the depression was caused by meteorite impact. The key evidence was the presence of coesite, which, in unmetamorphosed rocks, can only be formed by the shock pressures associated with meteorite impact. The coesite was found in suevite from Otting quarry, but even before, Shoemaker was encouraged by St. George's Church in Nördlingen, which is built of locally derived suevite. The suevite was formed from mesozoic sediments shocked by the bolide impact. The Ries impact crater was a rampart crater, thus far a unique finding on Earth. Rampart craters have almost exclusively been found on Mars. Rampart craters exhibit a fluidized ejecta flow after impact of the meteorite, most simply compared to a bullet fired into mud, with the ejecta resembling a mudflow. Another impact crater, the much smaller ( diameter) Steinheim crater, is located about west-southwest from the center of Ries. It had previously been thought that the two craters formed simultaneously by the impact of a binary asteroid 14.8 million years ago, but a study published in 2020 suggests that Steinheim could actually be about 500,000 years younger than Nördlinger Ries. Recent computer modeling of the impact event indicates that the impactors probably had diameters of about (Ries) and (Steinheim), had a pre-impact separation of some tens of kilometers, and impacted the target area at an angle around 30 to 50 degrees from the surface in a west-southwest to east-northeast direction. The impact velocity is thought to have been about . The resulting explosion had the power of 1.8 million Hiroshima bombs, an energy of roughly 2.4 joules. The