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
planets and moons in our solar system, including our own moon, are pock-marked with loads of craters. ; `2 [5 I3 I- e- y7 f) I: F, ^
But because Earth has a protective atmosphere and is geologically active — with plate tectonics and volcanic
& N$ B) [; f& m- A6 f5.39.217.76eruptions, mostly relatively young oceanic crust, and harsh weathering from wind and water — impact 公仔箱論壇  h& P) c6 g+ I$ y
structures don’t last long and can be tough to come by.3 `. ]8 N6 [1 x/ S* u
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But on a few old pieces of continent, especially in arid deserts, the marks of asteroids have been preserved.
One well-known example is our own Barringer crater, also known as Meteor Crater, in Arizona. The images here
$ w/ V) Q1 }8 A8 h8 g8 Q公仔箱論壇show some of the biggest, oldest and most interesting impact craters on the planet.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。8 _9 g2 n* L6 Q) Q
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Aorounga crater, pictured above and below, is one of the best preserved impact craters on Earth, thanks 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。, E& w" T, R* @/ F3 j* E& {
in part to its location in the Sahara Desert in Chad. The 10 mile-wide crater is probably around 350 million
* L' \3 v) d7 W# {" nyears old. The stripes are alternating rock ridges and sand layers, known as yardangs, caused by persistent 5 \/ Z$ B+ G. C& b9 r  R6 w7 J
unidirectional wind. The image above was taken by astronauts in the International Space Station in July. tvb now,tvbnow,bttvb/ ^7 |6 m' j% x3 ]+ K
In the radar image below, taken from the space shuttle in 1994, reveals that Aorounga may be one of two or three craters.5.39.217.767 @- i$ O, ~9 X9 W6 a' d+ O
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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" G, S5 d5 {0 N$ M' I( D
geologist Eugene Shoemaker for whom the Comet Shoemaker-Levy 9 is also named. The age of the crater unclear, but it
5 e" R9 u& K2 j2 Etvb now,tvbnow,bttvbcould be 1.7 billion years old, which makes it the oldest known impact in Australia. The brightly colored splotches are
seasonal salt-water lakes. This image was taken by the Landsat 7 satellite.tvb now,tvbnow,bttvb$ C8 b: [; v# S( ~6 P7 K  {

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The Manicouagan Crater in northern Canada is one of the largest impact craters known on Earth. The impact occurred & k6 B, O, @8 b  x" t% b
around 210 million years ago at the end of the Triassic period and may have caused a mass extinction that killed around
8 V4 S0 O% E/ X( N, x60 percent of all species. Though the crater has mostly eroded, Lake Manicouagan outlines what is left of the 43-mile wide
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.
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This crazy looking structure in Western Australia is called the Spider crater, for obvious reasons. Geologists determined it was
( z& R( I# O! M6 T: J, i# Man impact crater when they found shatter cones, telltale cone-shaped, grooved rocks found only around impacts. The crazy 5.39.217.767 j, o$ L7 a$ l( z2 K3 `3 m3 w% k
looking legs surrounding the impact are mostly due to erosion of different rock layers. The harder sandstone ridges withstood 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。) {. p3 y& L' N: O! [
the weathering of wind and water better than the softer intervening layers. The crater is somewhere between 600 million 5.39.217.76! U# b6 z9 ?3 t* y
and 900 million years old and the raised area at its center is around 1,600 feet wide.# i; k, a! I9 `- b: }# h) \/ Q

$ K! L5 d9 B1 BThe image above is a false-color image taken by the Advanced Spaceborne Thermal Emission and Reflection Radiometer on
. O4 k' V4 t$ F+ n, z% V3 GNASA’s Terra. The true-color image below was captured by Taiwan’s Formost-2 satellite
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The Gosses Bluff crater in Australia’s Northern Territory sits between two mountain ranges. The raised circular feature in the , H; h" q1 I% c* I
center of the structure is around 2.8 miles across, but the original crater rim was probably at the edge of the surrounding 公仔箱論壇3 {, _; \7 X; D
grayish area. The crater was formed caused by an asteroid impact around 140 million years ago.公仔箱論壇2 F. C6 r$ l5 C1 N& I

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2 `1 [/ m' I8 F$ B5 ZClearwater Lakes in Quebec, Canada were formed by a pair of asteroid impact craters. The impacts probably occurred 8 i# C$ t+ |( t: c# ]# Q8 d
simultaneously around 290 million years ago. The larger crater measures 22 miles across.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。" l6 V' c( j- X( ~

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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
2 R, a1 `! U9 A) t1.5 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
; F# p  P; b! |7 E% W6 C1 {6 j the space shuttle. Irregular surfaces show up brightly and smooth areas are dark. The white splotch at the bottom of the tvb now,tvbnow,bttvb" K9 v& \0 j: o  b
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 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。8 K" k" M2 F0 z! v' a
ejected during the impact, the red is limestone outcrop and the green areas are mostly vegetation. The impact occurred 7 d( E7 k1 E0 Y0 X) X5 }+ w
around 5 million years ago.
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: F8 f/ d5 T* y. d# b, p6 d5.39.217.76The Lonar crater in Maharashta, India is around 6,000 feet wide and 500 feet deep and contains a saltwater lake.
7 I" r; M# X  E6 L; SScientists determined the structure was caused by an asteroid through clues such as the presence of maskelynite, 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。$ v7 ~5 L9 c# m- C
a glass that is only formed by extremely high-velocity impacts. The impact occurred around 50,000 years ago.
This image was captured by the Advanced Spaceborne Thermal Emission and Reflection Radiometer on NASA’s
Terra satellite. It is a simulated true-color image  h# l- e9 u, Q* G6 P( r
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The Vredefort Dome in South Africa is possibly the oldest and largest clearly visible asteroid impact on Earth.
. ?* j9 `) P- @! e5 tThe 155-mile crater is approximately 60 miles southwest of Johannesburg and was formed around 2 billion 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。' ^' Q% r* f, U4 H

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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
% s1 }" ~' E& p, L- Q; u- Ia 300-mile wide asteroid would look impacting Earth. This event probably would have killed everything on the planet.
. T: \$ j- b& n: v( F公仔箱論壇Fortunately, NASA says nothing this big is headed our way anytime soon.