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
+ i/ `0 ]0 a4 n/ o5 T" cplanets and moons in our solar system, including our own moon, are pock-marked with loads of craters.
& v" u- C- s- A0 N" stvb now,tvbnow,bttvbBut because Earth has a protective atmosphere and is geologically active — with plate tectonics and volcanic 5.39.217.77:8898' W$ i; c3 U* z1 q1 I- y. B
eruptions, mostly relatively young oceanic crust, and harsh weathering from wind and water — impact * K- ^+ L! z" z5 b
structures don’t last long and can be tough to come by.
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" C2 H. Z9 X+ {tvb now,tvbnow,bttvbBut on a few old pieces of continent, especially in arid deserts, the marks of asteroids have been preserved. 5.39.217.77:8898; C- H% ]) h. a& ~4 H1 P
One well-known example is our own Barringer crater, also known as Meteor Crater, in Arizona. The images here
  w+ N' y1 O. R5 m% w1 `  x" D' dTVBNOW 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。show some of the biggest, oldest and most interesting impact craters on the planet.
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! k( z8 n6 I4 w8 K, K0 b, dTVBNOW 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。Aorounga crater, pictured above and below, is one of the best preserved impact craters on Earth, thanks
+ m7 }1 U" @9 v7 C$ s6 QTVBNOW 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。in part to its location in the Sahara Desert in Chad. The 10 mile-wide crater is probably around 350 million - H% m- v6 b: Q
years old. The stripes are alternating rock ridges and sand layers, known as yardangs, caused by persistent tvb now,tvbnow,bttvb& H0 c9 O# y6 `
unidirectional wind. The image above was taken by astronauts in the International Space Station in July. 5.39.217.77:8898$ p" R7 a7 Q, n; W. X
In the radar image below, taken from the space shuttle in 1994, reveals that Aorounga may be one of two or three craters.% X6 L* {+ _# k. Q; F: J
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% i& J! P, q  f" q# c5.39.217.77:8898The Shoemaker crater in Western Australia, formerly known as the Teague crater, was renamed in honor of the planetary 0 w1 F' v' H% }" |$ V
geologist Eugene Shoemaker for whom the Comet Shoemaker-Levy 9 is also named. The age of the crater unclear, but it . L5 }, C5 y! f7 z
could be 1.7 billion years old, which makes it the oldest known impact in Australia. The brightly colored splotches are 公仔箱論壇3 ~8 ~5 a6 h0 ], [( T" D
seasonal salt-water lakes. This image was taken by the Landsat 7 satellite.
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/ _) a$ N8 s  ^5 l2 WThe Manicouagan Crater in northern Canada is one of the largest impact craters known on Earth. The impact occurred 公仔箱論壇, H( ?' D( S4 P$ i, f  Y
around 210 million years ago at the end of the Triassic period and may have caused a mass extinction that killed around 8 t" M' U+ W, O  A
60 percent of all species. Though the crater has mostly eroded, Lake Manicouagan outlines what is left of the 43-mile wide 公仔箱論壇2 E6 D" w. b: M5 G  d) _# C
impact structure. The asteroid that created the crater is thought to have been about three miles wide. Today the lake is a 5.39.217.77:88988 G7 Y$ i3 Z$ `' W' g
reservoir and popular salmon fishing location.
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- d' R0 U/ Q# I3 ^6 M# D% X9 Dtvb now,tvbnow,bttvbThis crazy looking structure in Western Australia is called the Spider crater, for obvious reasons. Geologists determined it was ) Y2 @' w9 }% @" k0 v& T3 f
an impact crater when they found shatter cones, telltale cone-shaped, grooved rocks found only around impacts. The crazy
* J" c; Y, e  q" E/ i0 ^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。looking legs surrounding the impact are mostly due to erosion of different rock layers. The harder sandstone ridges withstood
) W8 ^$ M& {$ O9 Q1 N& `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。the weathering of wind and water better than the softer intervening layers. The crater is somewhere between 600 million + Y+ V0 i& A8 f- H" ], C) Y" |8 n
and 900 million years old and the raised area at its center is around 1,600 feet wide.
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3 S* C# D/ I" F: P5.39.217.77:8898The image above is a false-color image taken by the Advanced Spaceborne Thermal Emission and Reflection Radiometer on
9 q) @6 ^6 d: X9 {公仔箱論壇NASA’s Terra. The true-color image below was captured by Taiwan’s Formost-2 satellite
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* ~6 C. n9 S2 o! a; K2 y, X2 _5.39.217.77:8898The Gosses Bluff crater in Australia’s Northern Territory sits between two mountain ranges. The raised circular feature in the 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 @6 j6 x1 ~) e5 U
center of the structure is around 2.8 miles across, but the original crater rim was probably at the edge of the surrounding
7 ?- J, i: j, B( S' vTVBNOW 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。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。! _3 l" O' l9 [; P- I/ l

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Clearwater Lakes in Quebec, Canada were formed by a pair of asteroid impact craters. The impacts probably occurred
. y- l& @2 L. j0 Ltvb now,tvbnow,bttvbsimultaneously 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 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。, Z/ X7 U5 c! p: r
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
. [# E7 M( g+ d# |+ _" u$ X9 H, b the space shuttle. Irregular surfaces show up brightly and smooth areas are dark. The white splotch at the bottom of the 公仔箱論壇: L& M4 O( F5 o; s6 `2 H2 f
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
- T' K. ?! p% m# W! X, lejected during the impact, the red is limestone outcrop and the green areas are mostly vegetation. The impact occurred
+ y3 }. x' {8 P9 J/ laround 5 million years ago.
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0 L# _# I$ \% `! r. ]% X# ?) BThe Lonar crater in Maharashta, India is around 6,000 feet wide and 500 feet deep and contains a saltwater lake.
/ U/ w. W4 q0 {3 x& Z5.39.217.77:8898Scientists determined the structure was caused by an asteroid through clues such as the presence of maskelynite, 公仔箱論壇" r' i6 Y0 P' M9 A: \4 F/ M' @3 j
a glass that is only formed by extremely high-velocity impacts. The impact occurred around 50,000 years ago. 0 _/ k; E! t$ R) [# R8 l
This image was captured by the Advanced Spaceborne Thermal Emission and Reflection Radiometer on NASA’s 公仔箱論壇+ a8 `  T/ b% \6 E: @4 w+ Z
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.
' h& i1 @  g7 uThe 155-mile crater is approximately 60 miles southwest of Johannesburg and was formed around 2 billion years ago.
) @) D9 t1 U+ c  ~7 O" c9 qTVBNOW 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。
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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
2 t! X) L0 J+ P( htvb now,tvbnow,bttvba 300-mile wide asteroid would look impacting Earth. This event probably would have killed everything on the planet.
, V/ k, v) R( ~5 [Fortunately, NASA says nothing this big is headed our way anytime soon.