Nature Notes: The Odessa Meteor Crater

Limestone strata were raised and bent by the impact of the Odessa meteor, and the folded rocks form the rim of the crater today.
Limestone strata were raised and bent by the impact of the Odessa meteor, and the folded rocks form the rim of the crater today.

The Odessa Meteor Crater: A Subtle Feature Tells a Cosmic Story

By Andrew Stuart

Five miles west of Odessa, a 600-foot-wide circular hole marks the West Texas landscape. It’s shallow – just 15 feet deep. The Odessa Meteor Crater is a subtle feature, but it tells an explosive story – with truly cosmic implications.

“Trying not to appear in the least excited before these cow-men is a job, to say the least,” Daniel Barringer Jr. wrote to his father in June 1926. He’d just visited the Odessa crater, and he thought he’d seen paydirt.

Twenty-four years earlier, Barringer’s father had acquired a site in Arizona – a deep, mile-wide hole that’s now Meteor Crater National Landmark. Most geologists said it was volcanic. Barringer was convinced it was from a meteor’s impact. There were iron rocks at the site. Barringer believed that beneath the crater lay the meteor’s main mass – and a fortune in iron.

The Barringers knew Odessa was something similar. They tried to purchase it – and failed. Just as well. Neither the Arizona nor the Odessa craters contained an iron “motherload,” and Barringer nearly went broke mining in Arizona.

Yet, in his theory of meteor impact, he’s been vindicated.

Debate continued till the 60s, but scientists now agree that objects from space have shaped the Earth’s landscape. Odessa was among the first sites identified as a meteor crater.

It happened some 63,000 years ago. Out of the northwest, an object came blazing out of the sky. It was relatively small – perhaps 50 feet in diameter. But it was traveling very, very fast.

Charles Hemann is president of the West Texas Astronomers. The meteor, he said, was moving up to 26 kilometers per second – or 60 thousand miles an hour.

“They think that in a 2-kilometer radius from the impact site, you would have had instant death, whatever was there, from the explosion and the shock wave,” Hemann said. “They estimate the wind speeds right after the explosion to be 621 mph. So it’s a pretty energetic event.”

Buried limestone strata were thrown to the surface – visitors see these folded rocks today. Once a hundred feet deep, the crater filled over time.

More than 3,000 lbs of meteorite material have been found nearby. But efforts to find the main mass – with a shaft drilled by Works Projects Administration crews in the 40s – were doomed to fail.

“It pretty much detonated as it touched the ground,” Hemann said, “and a lot of that material was vaporized, and then what was left over got strewn all over the place.”

The Odessa Meteor Crater is a National Natural Landmark, and its on-site museum is managed by the Odessa Meteoritical Society.
The Odessa Meteor Crater is a National Natural Landmark, and its on-site museum is managed by the Odessa Meteoritical Society.

Where did this object come from?

Stargazers mark their calendars for known meteor showers – the Perseid, the Leonid. These showers are particles ejected by comets.

But there are also “sporadic meteors,” those unexpected “shooting stars” seen on West Texas nights. These meteors originate in the asteroid belt, between Mars and Jupiter. Most are destroyed in the atmosphere. Some – like the Odessa meteor – reach the ground.

Geologists were initially skeptical the Earth’s landscape was altered by such abrupt events, as opposed to slow processes. The Odessa crater helped change our understanding.

We now know that in the early solar system, the Earth was routinely bombarded. Indeed, the Moon was created when a Mars-sized object struck a “glancing blow” to the Earth. Such collisions declined as the solar system aged – but they haven’t stopped.

The Odessa meteor’s effects were intense, but local. But larger meteors can fundamentally alter life on Earth. The impact of a 6-miles-wide meteor likely contributed to the dinosaurs’ extinction.

Across the world, only a few dozen craters have been found. West Texas is home to two. Sierra Madera, a low mountain near Fort Stockton, was created by a meteor, long before Odessa.

The implications are disconcerting, to say the least. Scientists around the world are monitoring for potentially devastating meteors. In 2012, NASA will test a defense mission – launching a spacecraft to collide with an asteroid and change its trajectory.

“If we can catch them early,” Hemann said, “and know what their orbits are, we can actually figure out: 20 years from now, this thing is going to come back around and it’s got a pretty good chance of hitting us – what can we do? There are a lot of ideas about how we can deal with those kinds of events, if we have enough warning.”

The Odessa crater might be unassuming, but it puts our place in the universe in perspective.

Nature Notes is supported by the Shield-Ayres Foundation. This episode was written by Andrew Stuart.