Donald Bogard
The NASA scientist who found Martian air trapped in a meteorite in 1983, proving that some meteorites come from Mars.
Key facts
- Nationality
- American
- Field
- Geochemist
Donald D. Bogard worked at NASA's Johnson Space Center in Houston, where he measured the noble gases, such as helium, argon and xenon, trapped inside meteorites and lunar rocks. These gases can reveal how old a rock is, how long it travelled through space, and where it came from.
For years scientists had wondered about a small group of unusual meteorites, the shergottites, nakhlites and chassignites, known together as the SNC meteorites. They were volcanic rocks that had crystallised only about 1.3 billion years ago or less, far younger than almost any asteroid rock. Some suggested they came from Mars, but proof was missing.
In 1983 Bogard and his colleague Pratt Johnson studied pockets of black glass in the Antarctic meteorite EETA 79001, a shergottite. The glass had formed in an impact and had trapped gas as it melted. When they measured the gas, its mix of nitrogen, argon, xenon and other gases matched the Martian atmosphere as measured by NASA's Viking landers in 1976 almost exactly, and was quite unlike Earth's air.
This was the clinching evidence that the SNC meteorites came from Mars. More than 300 Martian meteorites are now known, and they are the only pieces of Mars that scientists can hold in their hands.
On the timeline
See more
The Shergotty meteoriteThe Nakhla meteoriteThe Chassigny meteorite