Lat November scientists announced they found evidence of a meteor crater under Greenland's ice sheet.
/ A.M. Costa Rica wire services
photo.



-Published: Wednesday, October 9, 2019-


Climate may not be the biggest fear


By Jay Brodell

Climate alarmists have been likened to the folk character Chicken Little, who thought the sky was falling after being hit on the head by an acorn.

Based on recent discoveries, the sky may really be falling, although climate is not the reason.

The situation was illustrated last April 23 when a space rock the size of a human hand fell into a home in La Caporal de Aguas Zarcas in San Carlos. The meteorite was in the news Tuesday because a collector donated it to the Field Museum in Chicago.

A rock that size is unlikely to do more than local damage. However new technology is revealing that the earth is under constant siege from space.

Lat November scientists announced they found evidence of a meteor crater under Greenland's ice sheet. That crater was 19 miles or 30 kilometers wide. And this year the same group announced they have spotted a second likely crater just 100 miles for the first, also using ground-penetrating radar.

In 2006 another scientific group, using photos from space, said they located a giant crater under the Indian Ocean. They estimated the impact happened about 5,000 years ago.  This one is 18 miles or 29 kilometers in diameter. This impact has been named the Burckle Crater, and evidence of the force can be seen in Madagascar to the west and Australia to the east.  A giant tsunami caused by the impact is believed to have decimated coastal life for thousands of miles.

Scientists found the Burckle Crater by following signs of giant V-shaped hills in Madagascar and similar configurations in Australia. They said they believe these hills were thrown up by a giant tsunami caused by the impact. The hills top out at 600 feet above sea level, so the wave must have been much higher. Remains of sea creatures are in the hills, showing that the material was thrust up from the ocean.

Using the same techniques of tracing tsunami patterns, researchers have found a number of suspected impact craters in the sea, they said, suggesting that such catastrophes are much more frequent than had been thought. Some scientists estimate that a meteor that makes a 19-mile crater would kill about a quarter of the life on the planet.

Researchers are trying to link the craters in Greenland to the rapid end of the last Ice Age or the abrupt change in climate 12,800 years ago. James Kennett, a California professor, speculated in a Science Daily article that the impact caused rapid climatic changes, megafaunal extinctions, sudden human population decrease and cultural shifts and widespread wildfires.

The end of the age of dinosaurs has been attributed to a meteor strike 65 million years ago in Mexico. More recently, the Barringer Crater in Arizona near Flagstaff is estimated to have been created about 50,000 years ago. That meteorite is estimated to have been 160 feet or about 50 meters in diameter. The subsequent crater is 1.2 kilometers wide.

The Tunguska event of 1908 flatted 2,000 square miles of uninhabited Siberian forest  and was blamed on an air burst of a small asteroid.

A 2013 meteor over Chelyabinsk, Russia, also exploded in the air, and this was witnessed by thousands. More than 7,000 buildings were damaged, and the size of the meteor was estimated to be 55 feet or 17 meters in diameter.

Many of the impact craters on earth have been obliterated by time and erosion. No so with the moon that lacks an atmosphere.

The U.S. National Aeronautics and Space Administration has formal programs to keep track of what the agency calls near earth objects. Said NASA:

“At the start of 2019, the number of discovered near-earth asteroids totaled more than 19,000. An average of 30 new discoveries are added each week. The 15,000 milestone, reached on Oct. 13, 2016, marked a 50 percent increase in the number of known near-Earth asteroids since 2013, when discoveries reached 10,000 in August of that year. More than 95 percent of these objects were discovered by NASA-funded surveys (primarily using ground-based telescopes) since 1998, when NASA initially established its Near-Earth Object Observations Program and began tracking and cataloguing them.”

NASA said it estimates that statistics show that about two thirds of the near earth objects larger than 460 feet in diameter have yet to be discovered. The agency picked that number because it said an impact of that or smaller size would only have regional consequences.

“Every day, 80 to 100 tons of material falls upon Earth from space in the form of dust and small meteorites (fragments of asteroids that disintegrate in Earth’s atmosphere),” said the agency.

NASA scientists are keeping an eye on Asteroid Bennu that makes a close approach to earth every six years due to its orbit around the sun. The asteroid will next pass within the moon's orbit in 2035, NASA said. The rock is 1,614 feet or 492 meters in diameter, said the space agency.

Despite popular movies to the contrary, NASA said that no known weapon could intercept a high-speed, earth-bound rock.



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Editor's note: Mr. Brodell, founder and former long-time editor of A.M. Costa Rica, can be reached at jay@amcostarica.com
































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