20 September 2013

Expert on Martian meteorites to speak at October 2013 Science Café


TALLAHASSEE, Fla. — While the Mars Curiosity rover scours the Red Planet for clues to its geology, a MagLab researcher is unearthing many of the planet's deepest secrets by analyzing its meteorites. You can learn more about these space rocks, and the information scientists glean from them, when MagLab geochemist Munir Humayun hosts the next Science Café on Oct. 1, from 6:15 to 7:30 p.m., at the Backwoods Bistro on East Tennessee near Leon High School. To get a good seat, plan to arrive early!

Geochemist Munir Humayun inside a clean lab.Geochemist Munir Humayun inside a clean lab.He'€™ll discuss how he determines if a rock is a meteorite from Mars or the Moon and how analysis of these stones reveals information about a planet’s volcanoes, water, weather and potential for life. He'll talk about the split personality, geologically speaking, that Mars appears to have. And he’ll talk about why a sliver of black rock has the world of outer-space geochemistry buzzing.

"Even though Martian meteorites are exceptionally rare — there are only about 100 or so known — most have been samples of a volcanic rock called basalt, and most have had surprisingly young ages," says Humayun, a professor at Florida State University and one of a handful of experts in Martian and Moon meteorites. "But now, a new Martian meteorite is providing a unique perspective on Martian geology. It's a collection of broken fragments of many different rocks formed by impact on Mars's surface and then cemented together by impact melt. It's also of great antiquity."

He estimates the meteorite, nicknamed Black Beauty, is more than 4 billion years old.

How this Martian rock landed in his hands is also an intriguing story, one that begins in West Africa.

"It was found by a Bedouin tribesman in the Sahara desert," Humayun says. Many of the Martian meteorites that exist today have been found in the Sahara by Bedouin tribesmen, who are known as "the best meteorite hunters in the world because they know that these rocks can fetch a pretty price in the marketplace of Casablanca."

And that's where these five stones, all part of the same unique meteorite, eventually surfaced. Three were bought by a wealthy American collector, while at least one was bought by a Frenchman, who rightly suspected that the stone was somehow different. He asked a museum in Paris to determine what it was — and the museum sent it to one of the world's leading meteorite detectives, Tallahassee'€™s Humayun.

When he analyzed the rock, using the MagLab's sophisticated mass spectrometers, he made a discovery that made him triple-check his own results.

"One of the more surprising aspects of Martian meteorites is that they are chemically unlike the rocks that the NASA rovers Spirit or Curiosity find in their travels over Mars's cratered surface," he says. "But the new meteorite is very much like the rock samples taken by the Martian rovers. It's very high in potassium, uranium and thorium, which are all radioactive."

Since its discovery, Black Beauty's value has jumped from $50 a gram to $15,000 a gram. You will be able to see part of the meteorite, as well as a lunar meteorite, at the café.

To find out more about this year's schedule, please visit our Science Café page.

The National High Magnetic Field Laboratory is the world’s largest and highest-powered magnet facility. Located at Florida State University, the University of Florida and Los Alamos National Laboratory, the interdisciplinary National MagLab hosts scientists from around the world to perform basic research in high magnetic fields, advancing our understanding of materials, energy and life. The lab is funded by the National Science Foundation (DMR-1157490) and the state of Florida. For more information, visit us online at nationalmaglab.org or follow us on Facebook, Twitter, Instagram and Pinterest at NationalMagLab.