Is mass extinction happened for dinasoures and other organism's because of asteriods collision?

Answer 1

The general consensus is that the extinction of the dinosaurs about 65 million years ago came about due to an impact with an object from space, most likely an asteroid. The geological evidence supporting this includes "shocked quartz" (alignment of quartz molecules pointing toward the source of impact), a layer of clay at the 65 million year mark, and the faint remnants of a circular impact crater situated around Chicxulub, in the Yucatan. (The Gulf of Mexico, for instance, is considered to be part of this impact crater).

The interesting facts about the layer of clay at 65 million years are that it covers a large and wide-spread area on the Earth's surface, and also that it is high in iridium -- an element that is quite rare on earth but fairly common in asteroids and meteors. The assumption is that an object rich in iridium hit the Earth at high speed, high enough that it was vaporized on contact with the Earth's crust; it mixed with seawater and with the mud from the sea bottom, and fell as a rain of mud that covered much of the planet's surface.

The conservative (scientifically, not politically :-) view is that the meteor strike caused atmospheric disturbances that blocked the Sun for several years (the eruption of Krakatoa in the late 1800s resulted in a similar, though less severe, disruption of the world climate). This caused plants to die; the lack of plants caused plant-eaters to die; the lack of plant-eaters caused meat-eaters to die.

A newer and more radical theory suggests that the explosive effects of an impact of this size would have been sufficient to kill off a large percentage of the world's living things within hours, perhaps even minutes, of hitting the surface. The shock wave, the intense heat, and the tsunami from such an impact, it is believed, would have covered at least half the earth in a very short period of time; the resulting forest and brush fires would have done more damage over the next few days.

And all this is NOTHING compared to the Permian Extinction, which occurred about 251 million years ago. There is even more debate on the trigger of that; what is known is that there was a continuous volcanic eruption that lasted 10,000 years, covering much of the Earth's surface with basalt and filling the atmosphere with carbon dioxide (raising the temperature) and ash and dust (blocking sunlight, causing plant death and eventually death down the food chain). Some geologists and palaeontologists now believe there is evidence that the eruptions may have been triggered by another cosmic collision, with an object even larger than the one at Chicxulub, in the ocean off the coast of what is now Australia. It is by no means universally accepted, but I believe the evidence (shocked quartz, plate fractures, disruption of the crust in a traditional impact pattern) is plausible enough to warrant further study.

Answer 2

There is now evidence that the much worse Permian extinction was caused by a much larger asteroid than the dinosaur asteroid. The leading theory used to be massive vulcanism in Siberia messing with the atmosphere, but now a crater has been identified under the Antarctic ice that would have been at the antipode at the time. The vulcanism may have only been a side effect of converging shock waves traveling through the earth from the other side.

Asteroid impacts in general have played a major role in the geological history of earth. I'd keep an eye on the sky; it could happen again.

Answer 3

Actually, yes and no. Scientist now realize the dinosaurs were slowly on their way out no matter what. For at least 4,000,000 year before the asteroid hit the Earth had been undergoing changes that was detrimental to the dinosaurs. They know this because of the KT layer separating the before and after layer from before the "asteroid." The KT layer shows plant pieces that are neither burned nor any signs of Charcoal. If there had been a massive planetary "fire event" then it would have left massive traces of a fire. It did not. Also, there are not traces of Charcol, meaning that the trees were not burned to a crisp.

So this just leave a small nuclear winter scenario and facts that the trees and plants were already dying off when the asteroid hit. Basically finishing off what had already begun.

Answer 4

That's ONE possibility. There are at least three others.

One other is a massive volcanic eruption. Certain lava fields in North America and in Siberia indicate the presence of enormous volcanic events hundreds and thousands of times larger than Krakatoa. The massive amounts of particulates, including soot and greehnouse gasses, would have caused extinctions similar to those postulated for asteroid impacts.

A third possibility is large solar flares. Rocks brought back from the Moon indicate that there was heating to about 1100 degrees there, within the last ten to twenty thousand years. Normally, the surface temperature on the sunlit Moon is around 325 degrees, like a slow oven. There was a short-term event during which the temperature was so hot, the rocks began to glaze like pottery in a kiln (which 325 degrees is NOT hot enough to do.) The solar flare did not last long enough for the rocks to become molten and flow, they just softened a little and glazed over on their top sides.

On Earth, the oceans would have boiled. There would have been hurricanes of live steam. Any species not killed directly by the radiation and particles from the Sun would have mutated drastically. The enormous amounts of water vapor in the atmosphere would precipitate out, leading to worldwide flooding conditions, and the rise of glaciers and icecaps at the coldest areas, the poles.

(I suspect that the American continents were in sunlight when that happened, leaving them sterilized and then men crossed the ice bridge over the Bering Strait, following herds of game animals which smelled the recovering plant life-- fodder, growing to the east and south.)

NASA has current photos of the polar ice cap on Mars shrinking, as the sun gets a little warmer. This global warming is NOT caused by Earth pollution!

A fourth possibility is that our atmosphere could have become tainted by the introduction of molecules from a cloud in outer space. We know that such clouds of molecules exist, because we have detected them by means of radio astronomy. There are none near us right now, but there may have been millions of years ago. If we passed through such a cloud of chemicals, our gravity would have gathered great amounts of them in. If the atmosphere was rendered poisonous, this kind of natural pollution or contamination could also have been responsible for mass extinctions.

Answer 5

Almost certainly. This is the best explanation for the K-T mass extinction, and it's a scientific theory.