Obolon' crater is a 20 km (12.4 mi) diameter buried meteorite

Meteorite

A meteorite is a natural object originating in outer space that survives impact with the Earth's surface. Meteorites can be big or small. Most meteorites derive from small astronomical objects called meteoroids, but they are also sometimes produced by impacts of asteroids...

 impact crater

Impact crater

In the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with a larger body...

 situated about 200 km (124.3 mi) southeast of Kiev

Kiev

Kiev or Kyiv is the capital and the largest city of Ukraine, located in the north central part of the country on the Dnieper River. The population as of the 2001 census was 2,611,300. However, higher numbers have been cited in the press....

 in Ukraine

Ukraine

Ukraine is a country in Eastern Europe. It has an area of 603,628 km², making it the second largest contiguous country on the European continent, after Russia...

 (Poltava Oblast

Poltava Oblast

Poltava Oblast is an oblast of central Ukraine. The administrative center of the oblast is the city of Poltava.Other important cities within the oblast include: Komsomolsk, Kremenchuk, Lubny and Myrhorod.-Geography:...

).
The site has been drilled, which revealed the presence of shocked minerals and impact melt rock; the high chlorine

Chlorine

Chlorine is the chemical element with atomic number 17 and symbol Cl. It is the second lightest halogen, found in the periodic table in group 17. The element forms diatomic molecules under standard conditions, called dichlorine...

 content of the latter suggesting that the area was covered by shallow sea at the time of impact.
One estimate puts the age at 169 ± 7 million years (Middle Jurassic

Jurassic

The Jurassic is a geologic period and system that extends from about Mya to  Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...

).

Hypothetical multiple impact event

It has been suggested by Geophysicist David Rowley of the University of Chicago

University of Chicago

The University of Chicago is a private research university in Chicago, Illinois, USA. It was founded by the American Baptist Education Society with a donation from oil magnate and philanthropist John D. Rockefeller and incorporated in 1890...

, working with John Spray of the University of New Brunswick

University of New Brunswick

The University of New Brunswick is a Canadian university located in the province of New Brunswick. UNB is the oldest English language university in Canada and among the first public universities in North America. The university has two main campuses: the original campus founded in 1785 in...

 and Simon Kelley of the Open University

Open University

The Open University is a distance learning and research university founded by Royal Charter in the United Kingdom...

, that Obolon' may have been part of a hypothetical multiple impact event which also formed the Manicouagan crater

Manicouagan crater

The Manicouagan Crater is one of the oldest known impact craters and is located primarily in Manicouagan Regional County Municipality in the Côte-Nord region of Québec, Canada, about north of the city of Baie-Comeau. Its northernmost part is located in Caniapiscau Regional County Municipality...

 in northern Quebec

Quebec

Quebec or is a province in east-central Canada. It is the only Canadian province with a predominantly French-speaking population and the only one whose sole official language is French at the provincial level....

, Rochechouart crater

Rochechouart crater

Rochechouart is an impact crater in France.The crater diameter is still under study but is expected to be about . Its most recent age estimate is 201 ±2 million years ago, placing it close to Triassic-Jurassic boundary. Since then the crater has been deeply eroded, and no trace of its original...

 in France

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

, Saint Martin crater

Saint Martin crater

Saint Martin is an impact crater in Manitoba, Canada.It is in diameter and its age is estimated at 220 ± 32 million years . The crater is not exposed at the surface.-Hypothetical multiple impact event:...

 in Manitoba

Manitoba

Manitoba is a Canadian prairie province with an area of . The province has over 110,000 lakes and has a largely continental climate because of its flat topography. Agriculture, mostly concentrated in the fertile southern and western parts of the province, is vital to the province's economy; other...

, and Red Wing crater

Red Wing crater

Red Wing or Red Wing Creek structure is a meteor crater located inMcKenzie County, North Dakota, about southwest of Watford City, North Dakota, United States....

 in North Dakota

North Dakota

North Dakota is a state located in the Midwestern region of the United States of America, along the Canadian border. The state is bordered by Canada to the north, Minnesota to the east, South Dakota to the south and Montana to the west. North Dakota is the 19th-largest state by area in the U.S....

. All of the craters had previously been known and studied, but their paleoalignment had never before been demonstrated. Rowley has said that the chance that these craters could be aligned like this due to chance are nearly zero.