Oct. 17, 2006 — Scientists were excited when they pulled a 154-pound meteorite from deep below a Kansas wheat field, but what got them most electrified was the way they unearthed it.
The team Monday uncovered the find 4 feet under a meteorite-strewn field using new ground-penetrating radar technology that someday might be used on Mars.
It was that technology which pinpointed the site and proved for the first time that it could be used to find objects buried deep in the ground and to make an accurate three-dimensional image of them.
"It validates the technique so we can use something similar to that instrument when we go to Mars," said Patricia Reiff, director of the Rice Space Institute.
Such GPR systems had been used in the past to locate smaller meteorites in Antarctica where ice allows easier penetration of the sonar. But until the Kansas dig, the technology had not been successfully used for ground detection in heavy soils — like on Mars — to find meteorites or water there.
The dig was likely the most documented excavation yet of a meteorite find, with researchers painstakingly using brushes and hand tools to preserve evidence of the impact trail and to date the event of the meteorite strike. Soil samples also were bagged and tagged and organic material preserved for dating purposes.
"When we find a piece of meteorite, each one is a new sentence we add to the book to understand the evolution of the solar system," said Essam Heggy, planetary scientist at the Johnson Space Center's Lunar and Planetary Institute in Houston.
Even before they had the pallasite meteorite out of the ground, the scientific experts at the site were able to debunk prevailing wisdom that the spectacular Brenham meteorite fall occurred 20,000 years ago. Its location in the Pleistocene epoch soil layer puts that date closer to 10,000 years ago.
"We know it is recent," said Carolyn Sumners, director of Astronomy at the Houston Museum of Natural Science, as she surveyed progress on the dig. "Native Americans could have seen it."
