Asteroid Impact Craters on Earth as Seen From Space

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% M% ^: z6 M; N( C- J3 h3 mwww.tvboxnow.comAsteroid impact craters are among the most interesting geological structures on any planet. Many other
+ l4 `& _& A5 g1 e: z5 r! q6 O4 `公仔箱論壇planets and moons in our solar system, including our own moon, are pock-marked with loads of craters. , p* M) D% s* l# a* k& C+ `
But because Earth has a protective atmosphere and is geologically active — with plate tectonics and volcanic 公仔箱論壇, D# q. F! j. _( @( p5 `, S
eruptions, mostly relatively young oceanic crust, and harsh weathering from wind and water — impact
6 f+ _3 @( M* O& U" T9 ?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。structures don’t last long and can be tough to come by.
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But on a few old pieces of continent, especially in arid deserts, the marks of asteroids have been preserved.
* N3 ~. @. k. Y6 ^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。+ j) L5 x! }7 ^, `2 M( a" T
show some of the biggest, oldest and most interesting impact craters on the planet.
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4 [0 i% C  x: U; ?Aorounga crater, pictured above and below, is one of the best preserved impact craters on Earth, thanks
; i) E2 o: q3 n. F( hTVBNOW 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 公仔箱論壇' l# a* \  @. @8 T$ l
years old. The stripes are alternating rock ridges and sand layers, known as yardangs, caused by persistent tvb now,tvbnow,bttvb! a3 h1 N1 S" i4 p6 a8 o$ C) k1 W
unidirectional wind. The image above was taken by astronauts in the International Space Station in July. $ b) H( Y# v" z8 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" W* N2 p2 ?' J5 |
geologist Eugene Shoemaker for whom the Comet Shoemaker-Levy 9 is also named. The age of the crater unclear, but it
& V4 e0 s8 o7 ]6 S! v% tcould be 1.7 billion years old, which makes it the oldest known impact in Australia. The brightly colored splotches are www.tvboxnow.com! w% ~* D3 C8 B) O) |$ b
seasonal salt-water lakes. This image was taken by the Landsat 7 satellite.
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7 t( p9 P$ l# S% |  M) I公仔箱論壇The Manicouagan Crater in northern Canada is one of the largest impact craters known on Earth. The impact occurred
- {7 J: x! \0 d% Laround 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。. {! b0 T' {# M2 F
60 percent of all species. Though the crater has mostly eroded, Lake Manicouagan outlines what is left of the 43-mile wide tvb now,tvbnow,bttvb' `0 ~) I  b$ ?  T- S
impact structure. The asteroid that created the crater is thought to have been about three miles wide. Today the lake is a
1 ]* T. K% h/ C% J; `7 U1 _5 nreservoir and popular salmon fishing location.$ Q3 R$ x" D+ s# K; T
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This crazy looking structure in Western Australia is called the Spider crater, for obvious reasons. Geologists determined it was tvb now,tvbnow,bttvb7 ?$ L0 `  ~) [
an impact crater when they found shatter cones, telltale cone-shaped, grooved rocks found only around impacts. The crazy 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。& A& @% O: W* y+ n8 v
looking legs surrounding the impact are mostly due to erosion of different rock layers. The harder sandstone ridges withstood
0 O: R2 z3 O8 ?. cthe weathering of wind and water better than the softer intervening layers. The crater is somewhere between 600 million
# ]3 x% g+ }' r1 D公仔箱論壇and 900 million years old and the raised area at its center is around 1,600 feet 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。6 Q9 F& w1 t: r
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The image above is a false-color image taken by the Advanced Spaceborne Thermal Emission and Reflection Radiometer on 公仔箱論壇' b* c1 c6 B- F! w" _$ o8 j0 N
NASA’s Terra. The true-color image below was captured by Taiwan’s Formost-2 satelliteTVBNOW 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。! I( _- z! c( r1 ]9 n7 k9 Q
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0 X1 b* K7 l: q) q公仔箱論壇The Gosses Bluff crater in Australia’s Northern Territory sits between two mountain ranges. The raised circular feature in the
8 [$ G( p* J& T: N; [- Z" l, [tvb now,tvbnow,bttvbcenter 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( P# W4 l" E3 x  b
grayish area. The crater was formed caused by an asteroid impact around 140 million years ago.
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+ E5 T, _* i" e" ?5 S公仔箱論壇Clearwater Lakes in Quebec, Canada were formed by a pair of asteroid impact craters. The impacts probably occurred 6 }& f: Z1 B( s8 N" m. f# a6 n
simultaneously around 290 million years ago. The larger crater measures 22 miles across.4 ]- b. G1 _$ N' u
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1 e- j0 K0 N. k5 L' r" s1 mtvb now,tvbnow,bttvbThe Roter Kamm crater in Namibia is hard to see in visible light, but shows up more clearly with imaging radar. The crater’s
3 B+ G7 l  W8 p3 f8 mwww.tvboxnow.com1.5 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
% a( ?+ h1 K/ l' }公仔箱論壇 the space shuttle. Irregular surfaces show up brightly and smooth areas are dark. The white splotch at the bottom of the
9 x) L( S- m6 m" |% ^* e6 u- P' cwww.tvboxnow.comphoto is a rocky hill, the darkest areas are wind-blown sand dunes, the blue around the crater’s rim may be material that was
* f, J. S5 G% o$ d2 `4 [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。ejected during the impact, the red is limestone outcrop and the green areas are mostly vegetation. The impact occurred
0 n$ L$ X1 r2 h5 n: K2 Y& f公仔箱論壇around 5 million years ago.5 E& G% p6 O- j/ Q# @6 p% D

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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.
$ v' ^! y( k) _5 x% fScientists determined the structure was caused by an asteroid through clues such as the presence of maskelynite, 1 J$ d9 w2 K* |0 c3 J; d( g. P5 ~: |
a glass that is only formed by extremely high-velocity impacts. The impact occurred around 50,000 years ago.
3 a6 g1 }9 q& h# oTVBNOW 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。This image was captured by the Advanced Spaceborne Thermal Emission and Reflection Radiometer on NASA’s www.tvboxnow.com# S1 c0 Q, n, |5 S7 v
Terra satellite. It is a simulated true-color imagewww.tvboxnow.com  l# ~' p7 E$ W8 }  v% k

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, Y! V! L+ \# z0 D+ l, e; pThe Vredefort Dome in South Africa is possibly the oldest and largest clearly visible asteroid impact on Earth.
0 e/ q, ^8 A5 b9 K8 H9 V6 ^1 S3 Vtvb now,tvbnow,bttvbThe 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 & r$ }* l% Y8 J6 t% _$ x5 [
a 300-mile wide asteroid would look impacting Earth. This event probably would have killed everything on the planet. # I3 I- J8 {4 Q; `) S' C
Fortunately, NASA says nothing this big is headed our way anytime soon.