Center for Meteorite Studies

Greenish rock found in Morocco may be first from planet Mercury

Arizona State University’s Center for Meteorite Studies recently received pieces of one of the rarest meteorites ever found. Aside from its peculiar green color, what makes this space rock so special is where it could come from: It may be the first known visitor from planet Mercury.

Last year, a group of 35 of these unusual space rocks was found in Morocco. Analysis suggests that the meteorite, called NWA 7325, came from Mercury, and not an asteroid or Mars. With its uncharacteristically chartreuse-green fusion crust and curious chemical composition, it does not resemble any other space rock documented by scientists.

Meteorite enthusiast Fredric Stephan donated two pieces of the green rock, totaling 10 grams. CMS now holds 10 grams of the 345 grams found.

“This unusual and precious donation is really an exciting sample and a wonderful addition to the center’s meteorite collection. Scientists have numerous meteorites for study, more than 50,000, but every so often something new comes along that gives us new insights into our solar system. More than anything, this sample will force us to look at what would really be the defining properties of a Hermian meteorite,” said Laurence Garvie, who curates the Center for Meteorite Studies’ collection of more than 1,800 separate meteorites.


Melissa Morris (assistant director of ASU’s Center for Meteorite Studies), meteorite collector Fredric Stephan, and Laurence Garvie (collection manager of ASU’s Center for Meteorite Studies) hold samples of the center’s newest acquisition: A meteorite that has been suggested to hail from planet Mercury. Photo by: Andy DeLisle

Although it has been hailed as the first meteorite from the solar system’s innermost planet, its origin is not certain.

“It is difficult, though modeling shows not impossible, to get a sample ejected from Mercury out to our orbit. Basically, Mercury is so close to the sun, it swallows up most rocks ejected from the surface by impacts,” explains Garvie.

However, based on its composition and low remnant magnetism, it is possible that it originated from the closest planet to the sun. NWA 7325 contains little iron but considerable amounts of magnesium, aluminum and calcium silicates — in line with data sent back from NASA’s MESSENGER spacecraft currently in orbit around Mercury.

Although scientists can’t say for sure where the meteorite comes from, they can say it is exceptional and very old, with an estimated age close to ~4.56 billion years. And even if this meteorite turns out not to be from Mercury, it still has properties that scientists have not observed before in a sample, and is, therefore, extremely interesting.

“CMS has a long tradition of working with private meteorite collectors for the benefit of planetary science. We are especially grateful to Fredric for his generosity in making this important contribution along with the many other valuable specimens he has donated to the center,” says Meenakshi Wadhwa, director of CMS and a professor in the School of Earth and Space Exploration.

Members of the public are invited to see this unusual sample that is now on exhibit on the second floor of ASU’s Interdisciplinary Science and Technology Building IV.

(Nikki Cassis)

Category: CMS News

Comments are closed.

Sign Up for Center Updates!

Be the first to learn about CMS events and news; sign up for email updates here!


Upcoming Events

September 2016
Sunday Monday Tuesday Wednesday Thursday Friday Saturday
August 28, 2016 August 29, 2016 August 30, 2016 August 31, 2016 September 1, 2016 September 2, 2016 September 3, 2016
September 4, 2016 September 5, 2016 September 6, 2016 September 7, 2016 September 8, 2016 September 9, 2016 September 10, 2016
September 11, 2016 September 12, 2016 September 13, 2016 September 14, 2016 September 15, 2016 September 16, 2016 September 17, 2016
September 18, 2016 September 19, 2016 September 20, 2016 September 21, 2016 September 22, 2016 September 23, 2016

Earth & Space Open House

September 24, 2016
September 25, 2016 September 26, 2016 September 27, 2016 September 28, 2016 September 29, 2016 September 30, 2016 October 1, 2016

Frequently Asked Questions

Click here to find the answers to the most common questions asked of the Center for Meteorite Studies!

Graduate Student Spotlight - Prajkta Mane

Prajkta Mane received her B.Sc. in Geology from the University of Mumbai (St. Xavier’s College) in 2008, followed by her M.Sc. in Applied Geology from the Indian Institute of Technology …

Meteorite of the Month


September's meteorite of the month is Carancas, an (H4-5) ordinary chondrite that fell in Peru, the afternoon of September 15, 2007. To date, over 340g of material have been recovered. …

CMS News

Catch up on all the latest news from the Center for Meteorite Studies!