A Not-So-Deep Impact
Sweaty search for a cosmic pebble in Arizona desert is 'real' science.
CASA GRANDE, ARIZONA — In this year's movies, scientists are forced to save the earth from asteroids the size of small European nations that are just waiting to smash into the planet, topple the Empire State Building, and end life as we know it.
In the desert outside Tucson, Ariz., however, David Kring would love to just find an intergalactic pebble or two.
"So far today, we've found barbed wire, lead from bullets, lots of fragments of rusty cans ... I also found a horseshoe," says Dr. Kring, a University of Arizona geologist who is leading a crew of scientists examining the area.
For Kring and his team of researchers, this lonely stretch of creosote-covered desert is where fiction and reality diverge.
A film about their sweaty-limbed, dust-coated search this week for fragments of a meteor that blazed across the sky and exploded in a fireball earlier this month wouldn't win any Oscars. But it is just this type of methodical search, repeated the world over, that has yielded clues into the deepest mysteries of the universe, and - just two years ago - gave scientists reason to think that life once existed on Mars.
Here in Arizona, though, Kring hopes he can find anything at all. "We don't know if there are any particles on the ground," he says. "This thing could have been completely pulverized during the explosion."
If there is anything left, the fragments would likely range from a fraction of an inch wide to the size of a basketball.
Fortunately, through hundreds of eyewitness accounts of the explosion from all over Arizona and parts of New Mexico and California, the team has narrowed the search to the vicinity of the small city of Casa Grande and the gas-stop town of Gila Bend. But that's still an area of about 100 square miles, making the quest a little like trying to find a needle in a haystack.
According to Kring, the explosion was so widely observed because it occurred in between two major metropolitan areas - Tucson and Phoenix. Also, the timing of the event, 8:58 p.m., meant many were outside enjoying the cool night air.
In addition, the interest in this meteorite has been heightened by a Tucson meteorite collector's offer to pay a reward of $5,000 for the first fragment found - $10,000 if the piece weighs more than a kilogram (2.2 pounds).
Both the UA Meteorite Recovery Program in Tucson - one of the few such university programs in the US - and the Center for Meteorite Studies at Arizona State University in Tempe will look at any rock for free. Most turn out to be average stones.
About 1 of every 200 is a meteorite, Kring says, adding with a laugh that he expects that average to worsen with the heightened interest. But, mind you, he's appreciative of that interest.
Without the hundreds of eyewitness calls, he doubts he and his colleagues would have been able to determine a starting point for the search.
Now the goal of the team, embarking on its second meteor search in 10 years, is to find any part of the meteorite's strewn field. That would allow the team to focus its search even more.
On Monday, the crew conducted the first of its series of field surveys - which will last throughout the summer - to the click-chirping of locusts in 103-degree temperatures.
A group of five scientists lined up at distances of between five and 10 yards and walked back and forth in straight lines, covering blocks of the one-square-mile site until the whole section had been covered.
Three scientists, including Kring, were equipped with metal detectors.
The rare moments of anticipation - "Target," Kring says, braking to a stop - turned out to be tinfoil from gum wrappers, wire, and other debris.
"When people throw gum wrappers out of the car, they don't know where it goes," Kring quips. "Let me tell you. It ends up here in the desert."