What are the types of Impact craters?
Impact craters range from small, simple, bowl-shaped depressions to large, complex, multi-ringed impact basins. Meteor Crater is a well-known example of a small impact crater on Earth.
How are craters distributed on the surface?
It is distributed outward from the crater's rim onto the planet's surface as debris. It can be loose materials or a blanket of debris surrounding the crater, thinning at the outermost regions. Rays – Bright streaks extending away from the crater sometimes for great distances, composed of ejecta material. What are the different kinds of craters?
What caused the increase in the rate of impact cratering?
Formed in a collision 80 million years ago, the Baptistina family of asteroids is thought to have caused a large spike in the impact rate. Note that the rate of impact cratering in the outer Solar System could be different from the inner Solar System.
Do impact craters produce melted rocks?
Impact craters produce melted rocks as well, but usually in smaller volumes with different characteristics. The distinctive mark of an impact crater is the presence of rock that has undergone shock-metamorphic effects, such as shatter cones, melted rocks, and crystal deformations.
Where are most impact craters found?
Meteors, comets and asteroids have slammed into the earth with a force many times greater than the most powerful nuclear bombs. Sometimes, mass extinction followed. There are roughly 180 known impact craters worldwide and fully a third of them—including some of the biggest—are located in North America.
Where can you find impact craters?
Impact craters on EarthBarringer Crater, a.k.a. Meteor Crater (Arizona, United States)Chesapeake Bay impact crater (Virginia, United States)Chicxulub, Extinction Event Crater (Mexico)Clearwater Lakes (Quebec, Canada)Gosses Bluff crater (Northern Territory, Australia)Haughton impact crater (Nunavut, Canada)More items...
Where are most of the craters on Earth?
10 Ma or moreNameLocationCountryVredefortFree StateSouth AfricaChicxulubYucatánMexicoSudburyOntarioCanadaPopigaiSiberiaRussia34 more rows
Which planet has the most impact craters?
MercuryAll of the planets in our Solar System have had a lot of craters. This was especially true in the past when there were many more asteroids traveling in our solar system than there are today.
Are impact craters rare?
Meteorite craters on earth are comparatively rare -- only about 70 have been identified, and these are recognized mainly on the basis of residual information such as shock-induced changes in the surrounding rock, rather than as prominent land forms.
Why are impact craters much more common on the planet Mercury?
Mercury and the Moon Impact craters dominate the surfaces of Mercury and the Earth's Moon. Both bodies lack liquid water on their surfaces that would erode impact craters over time. They also lack an atmosphere which, on planets like the Earth and Venus, could disintegrate meteoroids before they impact the surface.
Why does Canada have the most impact craters?
About 290 million years ago, two large meteorites crashed into Earth and formed the two impact craters the make up this lake system in Quebec's largest national park. Originally close to the equator, these craters were slowly pushed into northern Canada by millions of years of plate tectonics.
Are there impact craters in the ocean?
So far, no deep sea impact craters have been found, in spite of the large areas of the Earth which are and have been covered by deep seas. Davison and Collins (2007) claim there is still no definite relationship between impactor properties, water depth, and final crater diameter.
Why are impact craters more common on the Moon and Mars than on Earth?
Meteorite craters are more common on the Moon and Mars and on other planets and natural satellites than on Earth, because most meteorites either burn up in Earth's atmosphere before reaching its surface or erosion soon obscures the impact site.
How many impact craters are there on Earth?
But the surface of Earth, constantly eroded by wind and rain, hides its history. Just 128 confirmed impact craters have been spotted on Earth's surface.
What 2 planets have 53 moons?
Read MorePlanet / Dwarf PlanetConfirmed MoonsTotalMars22Jupiter5379Saturn5382Uranus272711 more rows•May 19, 2021
Does Mars have impact craters?
The Martian surface contains thousands of impact craters because, unlike Earth, Mars has a stable crust, low erosion rate, and no active sources of lava. So, impact craters on Mars are not obliterated as they are on Earth.
What is the name of the crater in Arizona?
Impact crater. "Meteor crater" redirects here. For the impact crater in Arizona commonly called "Meteor Crater", see Meteor Crater. An impact crater is an approximately circular depression in the surface of a planet, moon, or other solid body in the Solar System or elsewhere, formed by the hypervelocity impact of a smaller body.
Why are there craters on Mars?
Because of the many missions studying Mars since the 1960s, there is good coverage of its surface which contains large numbers of craters. Many of the craters on Mars differ from those on the Moon and other moons since Mars contains ice under the ground, especially in the higher latitudes. Some of the types of craters that have special shapes due to impact into ice-rich ground are pedestal craters, rampart craters, expanded craters, and LARLE craters .
Why are impact craters less common on Earth?
On other planets and moons that experience more active surface geological processes, such as Earth, Venus, Mars, Europa, Io and Titan, visible impact craters are less common because they become eroded, buried or transformed by tectonics over time.
What are some examples of impact craters?
Impact craters are the dominant geographic features on many solid Solar System objects including the Moon, Mercury, Callisto, Ganymede and most small moons and asteroids .
What is an impact crater?
An impact crater is an approximately circular depression in the surface of a planet, moon, or other solid body in the Solar System or elsewhere, formed by the hypervelocity impact of a smaller body. In contrast to volcanic craters, which result from explosion or internal collapse, impact craters typically have raised rims and floors ...
How often do craters occur on Earth?
The rate of crater production on Earth has since been considerably lower, but it is appreciable nonetheless; Earth experiences from one to three impacts large enough to produce a 20-kilometre-diameter (12 mi) crater about once every million years on average.
How deep is a transient cavity?
The depth of the transient cavity is typically a quarter to a third of its diameter. Ejecta thrown out of the crater do not include material excavated from the full depth of the transient cavity; typically the depth of maximum excavation is only about a third of the total depth.
Explore with Google Earth
While Earth is home to some incredible craters with equally incredible history, not every crater site is easily accessible in real life.
1. Barringer Crater
Barringer Crater is approximately 570 feet (174 meters) deep. (Image credit: Chris Saulit via Getty Images)
2. Lonar Crater
The Lonar crater site features in Hindu mythology and various temples are found along the edge of the crater. (Image credit: CR Shelare via Getty Images)
3. Wolfe Creek Crater
Wolfe Creek Crater lies in Wolfe Creek Crater National Park, Western Australia. (Image credit: Nordseegold via Getty Images)
4. Gosses Bluff (Tnorala)
Gosses Bluff (Tnorala) is a registered sacred site. (Image credit: TED MEAD via Getty Images)
5. Pingualuit Crater
Pingualuit is found in the heart of the Ungava plateau, Canada. (Image credit: Stocktrek Images via Getty Images)
6. Kaali Crater Field
The Kaali crater field is located on Saaremaa, Estonia's largest island. (Image credit: Krivinis via Getty Images)
What are the different types of craters?
Scientists describe other types of craters as well: 1 Multi-ring basins – A very large impact basin surrounded by as many as five or six circular rings of mountain chains in addition to the main basin rim. 2 Irregular craters – Craters with irregular shapes or multiple impact craters formed at the same time. Oblong craters can be created by impacts striking the surface at a very low angle. 3 Degraded craters – Craters that have become eroded due to weathering, lava flows, impacting, or downslope movement of material.
What are the most common surface features on many solid planets and moons?
Craters are the most common surface features on many solid planets and moons—Mercury and our Moon are covered with craters . This portion of the Moon is covered by numerous circular holes. These are impact craters, each of which was formed when an asteroid or comet collided with the Moon's surface.
Why is the crater elevated above the surrounding terrain?
It is elevated above the surrounding terrain because it is composed of material pushed up at the edge during excavation. Ejecta – Rock material thrown out of the crater area during an impact event. It is distributed outward from the crater's rim onto the planet's surface as debris.
How fast does an impactor hit Earth?
The faster the incoming impactor, the larger the crater. Typically, materials from space hit Earth at about 20 kilometers (slightly more than 12 miles) per second. Such a high-speed impact produces a crater that is approximately 20 times larger in diameter than the impacting object.
What are the dark areas on the Moon?
The large circular dark areas in the image are impact basins, created as huge impactors struck the Moon . Lava later flowed across the low floors of the basins, giving them a darker, smoother appearance than the surrounding, brighter highlands. The dark basins can be seen by the naked eye.
How many miles is the impact crater?
The crater has been extensively eroded, but is believed to originally have been as much as 300 kilometers (185 miles) across. Space shuttle image STS51I-33-56AA, courtesy of the Lunar and Planetary Institute.
What is irregular crater?
Irregular craters – Craters with irregular shapes or multiple impact craters formed at the same time. Oblong craters can be created by impacts striking the surface at a very low angle. Degraded craters – Craters that have become eroded due to weathering, lava flows, impacting, or downslope movement of material.
What happens when a solid crashes into something?
When a solid object crashes into something at these super fast speeds, it forms a crater regardless of how hard or tough it is. It immediately vaporizes and creates enormous shockwaves through the ground that melt and recrystallize rock.
How is an impact crater formed?
What Is an Impact Crater? An impact crater is formed when an object like an asteroid or meteorite crashes into the surface of a larger solid object like a planet or a moon. To form a true impact crater, this object needs to be traveling extremely fast—many thousands of miles per hour!
What is the largest impact crater on Earth?
Vredefort crater in South Africa is the largest known impact crater on Earth—almost 200 miles across! At over 2 billion years old, it is also one of the oldest. Because of erosion over this long time period, the crater is a bit difficult to see. article last updated April 23, 2020.
How old is the Tycho Crater?
Tycho Crater, in the moon's southern hemisphere. Credit: NASA. Tycho Crater, in the moon's southern hemisphere, is believed to be about 108 million years old—young, by moon standards.
Where is the meteor crater?
Earth: Meteor Crater. Meteor Crater in Arizona. Credit: image courtesy of the National Map Seamless Server (USGS)". Meteor Crater (also known as Barringer Crater) in Arizona was the first crater discovered to be formed by an extraterrestrial impact.
What is the fourth largest impact crater on Earth?
Technically tied with the Manicouagan Crater as the fourth largest verified impact crater on Earth, the Popigai Crater is said to have been the catalyst of the Eocene–Oligocene extinction event. The impact was so massive that the debris ejected from the collision site landed on other continents!
What is the second largest meteorite impact crater in the United States?
Nearby Landmark: Rocky Mountains. Source: craterexplorer.ca. The second-largest known meteorite impact crater in the United States, the Beaverhead Crater is so weathered and worn that it’s hard to visualize how it must have looked right after impact.
How old is the Vredefort Dome?
Age: 2.02 billion years. Nearby Landmark: The Vaal River. Source: wikimedia.org. The Vredefort Impact Crater is the largest crater in the world. While the ridge of the crater itself has worn away over time, the base of the formation remains and is known as the Vredefort Dome or the Vredefort Impact Structure.
How far is the Kara crater?
Kara Crater. Source: wikimedia.org. The Kara Crater is said to have originally measured closer to 75 miles across immediately following the time of impact, but has been eroded heavily over time. The Ust-Kara site, which lies directly offshore, was initially thought to have been a separate impact site.
What has eaten away the Acraman crater?
Extreme erosion over time has eaten away much of the original structure of the Acraman Crater, requiring scientists to infer its initial size indirectly. Over time, the impact depression naturally accumulated water and formed the salty Lake Acraman.
What is the name of the dam that was once a dry lake?
Nearby Landmark: Daniel-Johnson Dam. Source: wikimedia.org. Now known as the Manicouagan Reservoir, the once-dry Manicouagan Crater filled with water since the time of impact, forming the annular lake that people see today.
How big is the Chesapeake Bay crater?
Chesapeake Bay Crater. Size: 53 miles wide . Location: Virginia, USA. Age: 35 million years. Nearby Landmark: Rappahannock River. Source: wikimedia.org. Considered to be one of the best-preserved “wet-target” impact craters in the world, the Chesapeake Bay Crater is the largest known impact site in the United States.
What are the craters on Mars?
On Mars, impact craters are a key focus in the hunt for the planet’s warmer, wetter past. Rocks ejected by impacts contain minerals that formed in the presence of liquid water; some craters also show signs of ancient lakes.
What is the impact of craters on Mercury?
Impact craters on Mercury helped scientists solve a long-standing mystery. Mercury’s surface is unusually dark—and until flyovers by the MESSENGER probe, no one knew why. Infrared spectrometry showed dark, carbon-rich rock in and around impact craters.
What can we learn from impact craters?
Lessons from impact craters have been essential to developing our understanding of the past and present of the Solar System. Scientists study craters on planets, asteroids and moons to learn about the geological history of those bodies. The Apollo lunar missions opened our eyes to the changing rate of impacts throughout the history ...
How do impact craters work?
During an impact, buried material is ejected while outward pressure pushes the rock at the crater’s edge upward, forming a rim. These processes expose old, long-buried materials, making them accessible to probes and rovers sent to investigate these craters.
What was the original crust of Mercury?
The impacts had blown away the younger surface rocks, revealing Mercury’s original crust: a layer of graphite that floated on the planet’s early magma ocean. Hokusai, an impact crater on Mercury’s surface. NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington.
What happened to the solar system 4.4 billion years ago?
About 4.4 billion years ago, the inner Solar System—including Earth—was pummeled by impacts much larger and more frequent than anything seen today.
What happened to the outer planets as they migrated to their present positions?
Moreover, the giant outer planets were closer to the Sun. As they migrated to their present positions, smaller bodies were thrown into disarray and became impactors. Many details of this period are active areas of research—and impact craters are key to unraveling this complex history.
How many impact craters are there on Mars?
University of Colorado Boulder research team has catalogued 635,000 impact craters on Mars that are roughly a kilometre (0.6 miles) or more in diameter. It is the largest single database ever compiled of impact craters on a planet or a moon in our solar system. The Global Mars Crater Database will help in dating the age and geology of particular regions of Mars. [2]
How many comets are on Mars?
Researchers have estimated that Mars is bombarded by more than 200 small asteroids or bits of comets every year forming impact craters at least 12.8 feet (3.9 meters) across. This estimate is calculated based on the number of impact craters found in a systematic survey of a portion of Mars.
Overview
An impact crater is a depression in the surface of a planet, moon, or other solid body in the Solar System or elsewhere, formed by the hypervelocity impact of a smaller body. In contrast to volcanic craters, which result from explosion or internal collapse, impact craters typically have raised rims and floors that are lower in elevation than the surrounding terrain. Lunar impact craters range fro…
History
Daniel M. Barringer, a mining engineer, was convinced already in 1903 that the crater he owned, Meteor Crater, was of cosmic origin. Yet most geologists at the time assumed it formed as the result of a volcanic steam eruption.
In the 1920s, the American geologist Walter H. Bucher studied a number of sites now recognized as impact craters in the United States. He concluded they ha…
Crater formation
Impact cratering involves high velocity collisions between solid objects, typically much greater than the speed of sound in those objects. Such hyper-velocity impacts produce physical effects such as melting and vaporization that do not occur in familiar sub-sonic collisions. On Earth, ignoring the slowing effects of travel through the atmosphere, the lowest impact velocity with an object from space is equal to the gravitational escape velocity of about 11 km/s. The fastest imp…
Identifying impact craters
Non-explosive volcanic craters can usually be distinguished from impact craters by their irregular shape and the association of volcanic flows and other volcanic materials. Impact craters produce melted rocks as well, but usually in smaller volumes with different characteristics.
The distinctive mark of an impact crater is the presence of rock that has under…
Economic importance of impacts
On Earth impact craters have resulted in useful minerals. Some of the ores produced from impact related effects on Earth include ores of iron, uranium, gold, copper, and nickel. It is estimated that the value of materials mined from impact structures is five billion dollars/year just for North America. The eventual usefulness of impact craters depends on several factors especially the nature of the materials that were impacted and when the materials were affected. In some case…
Martian craters
Because of the many missions studying Mars since the 1960s, there is good coverage of its surface which contains large numbers of craters. Many of the craters on Mars differ from those on the Moon and other moons since Mars contains ice under the ground, especially in the higher latitudes. Some of the types of craters that have special shapes due to impact into ice-rich ground are pedestal craters, rampart craters, expanded craters, and LARLE craters.
Lists of craters
• List of impact craters on Earth
• List of possible impact structures on Earth
• List of craters on Mercury
• List of craters on the Moon
See also
• Cretaceous–Paleogene extinction event – Mass extinction event about 66 million years ago
• Crater illusion – Optical illusion
• Expanded crater
• Impact depth – Depth of projectile penetration