The Nördlinger Ries is an

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 ...

and large circular depression in western

Bavaria Bavaria ( ; ), officially the Free State of Bavaria (german: Freistaat Bayern, link=no ), is a state in the south-east of Germany. With an area of , Bavaria is the largest German state by land area, comprising roughly a fifth of the total l ...

and eastern

Baden-Württemberg Baden-Württemberg (; ), commonly shortened to BW or BaWü, is a German state () in Southwest Germany, east of the Rhine, which forms the southern part of Germany's western border with France. With more than 11.07 million inhabitants across a ...

. It is located north of the

Danube The Danube ( ; ) is a river that was once a long-standing frontier of the Roman Empire and today connects 10 European countries, running through their territories or being a border. Originating in Germany, the Danube flows southeast for , pa ...

in the district of

Donau-Ries Donau-Ries (''Danube-Ries'') is a ''Landkreis'' (district) in Swabia, Bavaria, Germany. It is bounded by (from the north and clockwise) the districts of Ansbach, Weißenburg-Gunzenhausen, Eichstätt, Neuburg-Schrobenhausen, Aichach-Friedberg, Au ...

. The city of

Nördlingen Nördlingen (; Swabian: ''Nearle'' or ''Nearleng'') is a town in the Donau-Ries district, in Swabia, Bavaria, Germany, with a population of approximately 20,674. It is located approximately east of Stuttgart, and northwest of Munich. It wa ...

is located within the depression, about south-west of its centre.

Etymology

"Ries" is derived from

Raetia Raetia ( ; ; also spelled Rhaetia) was a province of the Roman Empire, named after the Rhaetian people. It bordered on the west with the country of the Helvetii, on the east with Noricum, on the north with Vindelicia, on the south-west ...

, since the tribe of

Raetians The Raeti (spelling variants: ''Rhaeti'', ''Rheti'' or ''Rhaetii'') were a confederation of Alpine tribes, whose language and culture was related to those of the Etruscans. Before the Roman conquest, they inhabited present-day Tyrol in Austria, ...

lived in the area in pre-

Roman Roman or Romans most often refers to: * Rome, the capital city of Italy * Ancient Rome, Roman civilization from 8th century BC to 5th century AD *Roman people, the people of ancient Rome *''Epistle to the Romans'', shortened to ''Romans'', a lett ...

times.

Description

The depression is a

meteorite A meteorite is a solid piece of debris from an object, such as a comet, asteroid, or meteoroid, that originates in outer space and survives its passage through the atmosphere to reach the surface of a planet or moon. When the original object ...

formed 14.808 ± 0.038 million years ago in the

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

. 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 A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plat ...

origin. In 1960 Eugene Shoemaker and

Edward C. T. Chao Edward Ching-Te Chao (; November 30, 1919 – February 3, 2008) was one of the founders of the field of impact metamorphism, the study of the effects of meteorite impacts on the Earth's crust. Born in Suzhou, China, he was best known for ...

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

, which is built of locally derived suevite. The suevite was formed from mesozoic sediments shocked by the

bolide A bolide is normally taken to mean an exceptionally bright meteor, but the term is subject to more than one definition, according to context. It may refer to any large crater-forming body, or to one that explodes in the atmosphere. It can be a ...

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 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 ...

. 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 The Steinheim crater is a meteorite crater in Steinheim am Albuch, Heidenheim County, Baden-Württemberg, Germany. The crater is located at the north-eastern end of the Swabian Alb, 40km west of the much larger (24-km-diameter) Nördlinger Rie ...

, 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 A binary asteroid is a system of two asteroids orbiting their common barycenter. The binary nature of 243 Ida was discovered when the Galileo spacecraft flew by the asteroid in 1993. Since then numerous binary asteroids and several triple a ...

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

joule The joule ( , ; symbol: J) is the unit of energy in the International System of Units (SI). It is equal to the amount of work done when a force of 1 newton displaces a mass through a distance of 1 metre in the direction of the force appli ...

s. The Ries crater impact event is believed to be the source of moldavite tektites found in

Bohemia Bohemia ( ; cs, Čechy ; ; hsb, Čěska; szl, Czechy) is the westernmost and largest historical region of the Czech Republic. Bohemia can also refer to a wider area consisting of the historical Lands of the Bohemian Crown ruled by the Bohem ...

and

Moravia Moravia ( , also , ; cs, Morava ; german: link=yes, Mähren ; pl, Morawy ; szl, Morawa; la, Moravia) is a historical region in the east of the Czech Republic and one of three historical Czech lands, with Bohemia and Czech Silesia. The ...

(

Czech Republic The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The ...

). The tektite melt originated from a sand-rich surface layer that was ejected to distances up to downrange of the crater. The shape of the strewnfield suggests that the direction of impact was from the

west-southwest The points of the compass are a set of horizontal, radially arrayed compass directions (or azimuths) used in navigation and cartography. A compass rose is primarily composed of four cardinal directions—north, east, south, and west—each ...

. Stone buildings in Nördlingen contain millions of tiny

diamond Diamond is a solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. Another solid form of carbon known as graphite is the chemically stable form of carbon at room temperature and pressure, b ...

s, all less than across. The impact that caused the Nördlinger Ries crater created an estimated of them when it impacted a local

graphite Graphite () is a crystalline form of the element carbon. It consists of stacked layers of graphene. Graphite occurs naturally and is the most stable form of carbon under standard conditions. Synthetic and natural graphite are consumed on la ...

deposit. Stone from this area was quarried and used to build the local buildings.

Archaeology

On one edge of the Nördlinger Ries are the

Ofnet Caves The Ofnet Caves (german: Ofnethöhlen) are the remains of an underground karst system on the edge of the Nördlinger Ries in Germany. They are located on a limestone hill near Nördlingen, Bavaria. The caves became famous in 1908 when 33 prehisto ...

, where, at the beginning of the 20th century, archaeologists discovered thirty-three human skulls dating to the

Mesolithic The Mesolithic ( Greek: μέσος, ''mesos'' 'middle' + λίθος, ''lithos'' 'stone') or Middle Stone Age is the Old World archaeological period between the Upper Paleolithic and the Neolithic. The term Epipaleolithic is often used synonymo ...

period.

Astronaut training

The landing site for

Apollo 14 Apollo 14 (January 31, 1971February 9, 1971) was the eighth crewed mission in the United States Apollo program, the third to land on the Moon, and the first to land in the lunar highlands. It was the last of the " H missions", landings at ...

is a heavily craterized terrain, and one of the science goals of the mission was to sample ejecta from the impact that formed

Mare Imbrium Mare Imbrium (Latin ''imbrium'', the "Sea of Showers" or "Sea of Rains", "Sea of Tears") is a vast lava plain within the Imbrium Basin on the Moon and is one of the larger craters in the Solar System. The Imbrium Basin formed from the colli ...

. Nördlinger Ries is an easily accessible, large impact crater, making it a convenient analog for lunar craters. Because of this, it was used as a location to train Apollo 14 astronauts, so that they would be able to investigate lunar impact structures and related rocks. Astronauts

Alan Shepard Alan Bartlett Shepard Jr. (November 18, 1923 – July 21, 1998) was an American astronaut, naval aviator, test pilot, and businessman. In 1961, he became the second person and the first American to travel into space and, in 1971, he beca ...

and

Edgar Mitchell Edgar Dean Mitchell (September 17, 1930 – February 4, 2016) was a United States Navy officer and aviator, test pilot, aeronautical engineer, ufologist, and NASA astronaut. As the Lunar Module Pilot of Apollo 14 in 1971 he spent nine ...

, as well as Apollo 14 backup astronauts

Eugene Cernan Eugene Andrew Cernan (; March 14, 1934 – January 16, 2017) was an American astronaut, naval aviator, electrical engineer, aeronautical engineer, and fighter pilot. During the Apollo 17 mission, Cernan became the eleventh human being t ...

and Joe Engle, trained here from August 10 to August 14, 1970.

References

External links

Ries at Earth Impact Database

{{DEFAULTSORT:Nordlinger Ries Impact craters of Germany Miocene impact craters Neogene Germany Paleontological sites of Europe Landforms of Bavaria Landforms of Baden-Württemberg Natural regions of the Swabian Keuper-Lias Plains Geological type localities Donau-Ries