The dig, in an area named Brenham Field because of its proximity to the city of Brenham, is probably the most documented excavation yet of a meteorite. The newest find weighs 154 lbs and measures 18 by 12 by 12 inches, which is bigger than most such meteorites but average for this particular field.

    Researchers painstakingly used brushes and hand tools in order to preserve evidence of the impact trail and to date the event of the meteorite strike. Soil samples were also bagged and tagged, and organic material preserved for dating purposes.

    Researchers documented every aspect of the dig from various scientific disciplines. Among them were an archaeologist, a paleontologist, a naturalist, geologists, astronomers, and even an animator, who recreated the meteor fall.

    But Essam Heggy received the most attention. A planetary scientist at the Johnson Space Center's Lunar and Planetary Institute in Houston, it was his ground-penetrating technology that pinpointed the site and proved for the first time that the technology 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," Reiff said.

    Its location in the Pleistocene epoch soil layer puts the date of impact closer to 10,000 years ago, which disputes the commonly held theory that the Brenham meteorite fell 20,000 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."

    The Brenham meteorite scattered more than three tons of meteorite fragments in the vicinity. The meteorite field was discovered in 1882. Pieces of the Brenham meteorite have also been found as far away as 1,000 miles -- transported by Native American traders and buried in mounds by the Hopewell people more than 1,500 years ago.

    Some pieces were pounded into iron knives, ear ornaments, chisels, buttons and beads.

    For thousands of years, meteorites were the primary source of iron metal for peoples around the world. All natural iron rusts, or oxidizes. But only meteoritic iron is mixed with nickel, forming a steel alloy that is extremely strong and rust-resistant.

    The scientific expedition of the meteorite strewn field in western Kansas was put together by the Houston Museum of Natural Science and led by meteorite hunters Steve Arnold and Philip Mani. Johnson Space Center's Lunar and Planetary Institute, the Rice Space Institute at Rice University and George Observatory in Houston also sent researchers.

    "What is unique is not the size, but the fact it was found in context," said Patricia Reiff, director of the Rice Space Institute. Enditem

    (Agencies)