Asteroid Impact Craters on Earth as Seen From Space

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Asteroid impact craters are among the most interesting geological structures on any planet. Many other ; }7 D! R& f) N% n& D
planets and moons in our solar system, including our own moon, are pock-marked with loads of craters.
But because Earth has a protective atmosphere and is geologically active — with plate tectonics and volcanic 2 w: y/ @$ A: p- I( o! Q1 M2 V
eruptions, mostly relatively young oceanic crust, and harsh weathering from wind and water — impact
* D' ^  V9 t  H+ g公仔箱論壇structures don’t last long and can be tough to come by.9 k& ?( H: ?6 ]

But on a few old pieces of continent, especially in arid deserts, the marks of asteroids have been preserved. % O0 h- c4 ~% T/ ~) J9 _6 a  b
One well-known example is our own Barringer crater, also known as Meteor Crater, in Arizona. The images here TVBNOW 含有熱門話題，最新最快電視，軟體，遊戲，電影，動漫及日常生活及興趣交流等資訊。" B1 p$ C& f' D
show some of the biggest, oldest and most interesting impact craters on the planet.4 r5 y' s% c6 ]% E: i0 ~
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Aorounga crater, pictured above and below, is one of the best preserved impact craters on Earth, thanks
8 c: l' I. ]- Cin part to its location in the Sahara Desert in Chad. The 10 mile-wide crater is probably around 350 million
years old. The stripes are alternating rock ridges and sand layers, known as yardangs, caused by persistent 2 T  _9 U. R/ z4 m4 e
unidirectional wind. The image above was taken by astronauts in the International Space Station in July. 公仔箱論壇: Z0 ?5 T! v6 u+ b# N
In the radar image below, taken from the space shuttle in 1994, reveals that Aorounga may be one of two or three craters.
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The Shoemaker crater in Western Australia, formerly known as the Teague crater, was renamed in honor of the planetary 公仔箱論壇3 r9 n$ O& A# W
geologist Eugene Shoemaker for whom the Comet Shoemaker-Levy 9 is also named. The age of the crater unclear, but it ; b# M; V% R$ Z9 T- z
could be 1.7 billion years old, which makes it the oldest known impact in Australia. The brightly colored splotches are : o) D) Y* l) V
seasonal salt-water lakes. This image was taken by the Landsat 7 satellite.tvb now,tvbnow,bttvb' Z! V$ S2 ?9 a. Z
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The Manicouagan Crater in northern Canada is one of the largest impact craters known on Earth. The impact occurred * `; v$ Z7 g9 y% V9 u/ {
around 210 million years ago at the end of the Triassic period and may have caused a mass extinction that killed around TVBNOW 含有熱門話題，最新最快電視，軟體，遊戲，電影，動漫及日常生活及興趣交流等資訊。- L9 n  E* p) l: w/ Q
60 percent of all species. Though the crater has mostly eroded, Lake Manicouagan outlines what is left of the 43-mile wide TVBNOW 含有熱門話題，最新最快電視，軟體，遊戲，電影，動漫及日常生活及興趣交流等資訊。, d- X+ D8 q3 z
impact structure. The asteroid that created the crater is thought to have been about three miles wide. Today the lake is a
reservoir and popular salmon fishing location.5.39.217.777 H# q, x, ]0 d( k/ F
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This crazy looking structure in Western Australia is called the Spider crater, for obvious reasons. Geologists determined it was
an impact crater when they found shatter cones, telltale cone-shaped, grooved rocks found only around impacts. The crazy
4 T  I# c/ I9 C9 |looking legs surrounding the impact are mostly due to erosion of different rock layers. The harder sandstone ridges withstood 1 ?8 I( z5 A; W& K
the weathering of wind and water better than the softer intervening layers. The crater is somewhere between 600 million tvb now,tvbnow,bttvb1 E- b  I6 H- h) M3 e
and 900 million years old and the raised area at its center is around 1,600 feet wide.
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The image above is a false-color image taken by the Advanced Spaceborne Thermal Emission and Reflection Radiometer on
; I1 V# {0 K$ h' X; w5.39.217.77NASA’s Terra. The true-color image below was captured by Taiwan’s Formost-2 satellite公仔箱論壇3 S* ~6 p# D0 x
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The Gosses Bluff crater in Australia’s Northern Territory sits between two mountain ranges. The raised circular feature in the ' e  F/ \( ?$ V4 h
center of the structure is around 2.8 miles across, but the original crater rim was probably at the edge of the surrounding
! {8 r$ |9 |5 W9 r0 W公仔箱論壇grayish area. The crater was formed caused by an asteroid impact around 140 million years ago.TVBNOW 含有熱門話題，最新最快電視，軟體，遊戲，電影，動漫及日常生活及興趣交流等資訊。1 ~8 ]1 M$ H  u4 L7 @; x
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* [4 b+ ^2 _3 nClearwater Lakes in Quebec, Canada were formed by a pair of asteroid impact craters. The impacts probably occurred
3 Z3 n5 M/ T; u- ^3 L. \simultaneously around 290 million years ago. The larger crater measures 22 miles across.
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The Roter Kamm crater in Namibia is hard to see in visible light, but shows up more clearly with imaging radar. The crater’s
1.5 mile-wide rim stands out as a bright ring in the lower left of the image, which was taken by a radar instrument on board
( y' n0 v0 g% ~0 J5 k4 `" }- L. C the space shuttle. Irregular surfaces show up brightly and smooth areas are dark. The white splotch at the bottom of the
photo is a rocky hill, the darkest areas are wind-blown sand dunes, the blue around the crater’s rim may be material that was
' ~/ ~# E$ x0 A7 w2 [! c5.39.217.77ejected during the impact, the red is limestone outcrop and the green areas are mostly vegetation. The impact occurred
3 [2 v' y0 x8 `2 N, U9 haround 5 million years ago.' N: l4 T8 [# U. j! `4 ]4 v; z
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The Lonar crater in Maharashta, India is around 6,000 feet wide and 500 feet deep and contains a saltwater lake. / f3 |& P% H* H, [7 y* |3 d2 Q
Scientists determined the structure was caused by an asteroid through clues such as the presence of maskelynite, . q% T! e  E: C  \
a glass that is only formed by extremely high-velocity impacts. The impact occurred around 50,000 years ago.
5 L  v8 z7 ]2 g7 A4 D( b( I' o: PThis image was captured by the Advanced Spaceborne Thermal Emission and Reflection Radiometer on NASA’s
Terra satellite. It is a simulated true-color image
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The Vredefort Dome in South Africa is possibly the oldest and largest clearly visible asteroid impact on Earth.
The 155-mile crater is approximately 60 miles southwest of Johannesburg and was formed around 2 billion years ago.
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Artist’s rendering of a space object or phenomenon, so we couldn’t resist this beauty. This is one man’s idea of what
* c( ?4 @; F9 \a 300-mile wide asteroid would look impacting Earth. This event probably would have killed everything on the planet.
1 Y3 k! ^& ~! U: O! l+ O& aFortunately, NASA says nothing this big is headed our way anytime soon.