Deadly asteroid changed life’s evolution

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The remnants of a mass killer may be hidden away in Paris.

Charlie Glick owns a meteorite that some scientists say could possibly be a part of the giant asteroid that crashed into the Earth between 66 and 65 million years ago and brought the Mesozoic Era of geological time to an immediate end. The impact and the aftermath resulted in the extinction of not only the dinosaurs but also 75 percent of all life on Earth at the time.

So the big question is how could one asteroid strike be so devastating? Nothing in human experience comes close in comparison so understanding the devastation is not easy.

The asteroid was beyond massive. It was at least six miles wide and possibly larger. It was the equivalent of a mountain slamming into the Earth at more than 40,000 mph.

Upon impact, the asteroid blew out a 115-mile wide crater near what is now the Yucatan Peninsula in the Gulf of Mexico. The force of the impact pushed several miles deep into the planet’s crust and immediately vaporized thousands of cubic miles of rock that was ejected high into the atmosphere.

The fireball at ground zero instantly killed everything within a 625-mile radius. Thermal radiation set trees, grasses and other vegetation on fire.

Water displaced by the asteroid resulted in a tsunami that may have reached 1,000 feet high in some locations and penetrated miles inland. As the water flowed back to the sea it dragged untold amounts of land surface material with it and laid down deep deposits of debris fields.

The shock wave triggered an unprecedented earthquake of at least 10.1 on the Richter scale and may have been even more powerful. No earthquake in the time of humans has matched it.

And the bad events just kept coming. About eight minutes after impact, the ejecta from the crater started falling over a wide area. This material was blasted out at molten rock temperature and was still hot while falling. Some areas got buried under hundreds and possibly thousands of feet of hot grit. The falling debris started still more fires in other areas.

At the 45-minute mark, wind moving at 600 mph was generated as the atmosphere recovered.

Life much farther away did not suffer immediate annihilation although the world was ending. The sky grew dark as the ash from the explosion circled the globe in a matter of hours and the planet plunged into darkness.

Scientists differ on how long the darkness lasted. Nothing more than a twilight level of sunlight may have reached the surface for perhaps several years having a dramatic impact on plants and photosynthesis.

Others say the nuclear winter may not have been years long, but in the best-case scenario, it took many months for rainfall to clear the massive amount of soot and ash from the atmosphere. What came out of the air fell as acidic mud.

Worldwide fires caused by the asteroid strike released so many toxins into the air the protective ozone layer was destroyed, allowing the sun’s deadly UV radiation to get through.

While the sun was blotted out, global temperatures fell. When the skies cleared, temperatures went up and shot past normal into a period of excessive global warming because the impact immediately released an estimated 10,000 billion tons of carbon dioxide, 100 billion tons of carbon monoxide and 100 billion tons of methane — all greenhouse gases.

Recent studies also point to an increased period of volcanism in the same time period as the impact. It is possible the volcano activity was on the increase before the asteroid strike and the shock that followed led to continued significant activity, which put more ash and more toxic gases into the atmosphere.

Geologically speaking, it is hard to separate the asteroid impact and highpoint of the Deccan Traps, an ancient volcanic region of India where an area of more than 200,000 square miles is covered in basalt. The volcanic rock is up to 6,500 feet thick in places.

The Earth’s geography was much different 65 million years ago as all of the land was essentially in one location on one side of the world and this may have contributed to the mass extinctions. Two super continents existed as Laurasia and Gondwana. Continental drift — perhaps helped by the shock from the asteroid — eventually formed the globe as it is known today.

Laurasia became North America and Eurasia. South America, Africa, Australia, Antarctica and the Indian subcontinent were all originally part of Gondwana.

There is an argument if the asteroid had landed in one of the deep oceans the results — while devastating to coastal areas and the ocean environment — might not have resulted in a mass extinction of the dinosaurs and other land-based life forms.

If it had happened that way, life on Earth would be much different today having followed another evolutionary path.

We likely would not be here writing and reading about it.