Mysterious Crater Widens to Antarctica

March 31, 2008 -- A new report of tiny beads of meteor impact glass strewn high in Antarctica's Transantarctic Mountains may expand a debris field to a tenth of Earth's surface -- despite no sign of the crater which spewed out the molten rock 800,000 years ago.

The accidental discovery of the glass "microtektites" in the high mountains of Antarctica extends what's called the Australasian tektite strewn field south by nearly 2,000 miles (3,000 kilometers).

The microtektites were found while a team of researchers were searching the exposed rocks atop the Transantarctic Frontier Mountain for more pieces of an unrelated meteorite that disintegrated in the skies there long ago.

"The gradiometer kept on beeping at every fracture of the granitic bedrock surface," recalled Italian researcher Luigi Folco of the Museo Nazionale dell'Antartide, Università di Siena and the Italian Programma Nazionale delle Ricerche in Antartide.

A magnetic gradiometer detects minute changes in magnetic fields caused by rocks containing magnetic minerals. The most likely cause for the beeping was magnetic minerals in volcanic ash from one of the relatively recent volcanoes in the region.

"When we get back to the lab, to our great surprise, we found thousands of micrometeorite and cosmic spherules thus explaining the magnetic signal," Folco told Discovery News.

But they also found glass spheres 0.5 millimeter in diameter with a pale-yellow color, which is unusual for glassy cosmic spherules, which are the debris of meteors melting in Earth's atmosphere.