America’s Largest Asteroid Crater Is… In Iowa?

Welcome to Iowa; home of the hawkeyes, cyclones, and the biggest asteroid impact crater in the U.S.

When this rock hit central Iowa, it leveled nearly everything within a two hundred-mile radius. But it also provided some unexpected lasting benefits to the area.

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How Long Ago Did This Happen?

The giant asteroid struck the area around what is now Manson, Iowa way back during the Cretaceous Period, approximately 74 million years ago.

How Big Is The Crater?

The crater is an astonishing 22 miles wide and nearly three thousand feet deep.

It wasn't discovered until 1959, because it was long ago buried in over 100 feet of sediment, due to glacial retreat.

Did Iowa Look Different Back Then?

You bet it did. In fact, much of western Iowa was covered in a large inland sea. So was South Dakota, Nebraska, North Dakota, and part of western Minnesota.

How Did This Effect The Water?

The impact incinerated all the limestone rock in the region, which is why this part of Iowa still has soft water to this very day. The rest of the state has hard water, because the limestone was left in tact.

For a full look at the asteroid's impact on the region, check out this fantastic YouTube video from Geology Hub.

Story Source: Geology Hub via YouTube