At first, not many scientists agreed with the Alvarezes’ theory. Then, in 1990, geologists looking for oil off Mexico’s coast discovered a huge impact crater. It was buried under a mile of limestone. Underground imaging equipment showed that the crater fit the Alvarezes’ theory. It is exactly the right size and formed at exactly the right time to support their idea. | Meteors and Moon Rocks | Kids Discover
Could another large object hit Earth? In 1908, a rocky object exploded in Western Siberia with the force of several nuclear bombs. No one was killed in that sparsely settled place. But the explosion leveled trees in an area the size of New York City. | Meteors and Moon Rocks | Kids Discover
Earth would have craters just like the Moon’s if it didn’t have an atmosphere. That layer of gases allows Earth to have climate and weather. Rain and wind erode old craters. Plants and water cover them up, and natural disasters cause changes. Canyon Diablo in Arizona (above) is a rare case of a giant impact crater that has survived pretty much intact. A 15,000-ton meteorite crashed there about 50,000 years ago. | Meteors and Moon Rocks | Kids Discover
If oil spills in the Arctic and no one is around to clean it up, does it just stay there?
Not all rock formations are above ground. New Mexico’s Carlsbad Caverns began forming just before the time of the dinosaurs. Over millions of years, natural acids in water ate away at cracks in the underground limestone structure. The limestone was eroded, and cave-ins helped form giant underground chambers. One is called the Big Room. It’s 25 stories high and a third of a mile wide. | Ayers and Other Famous Rocks | Kids Discover