Meteorite From Mars is Water-Rich

by Nancy Atkinson on January 3, 2013

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Martian meteorite NWA 7034 weighs approximately 320 grams (11 ounces). Credit: NASA

A 2-billion-year-old rock found in the Sahara desert has been identified as a meteorite from Mars’ crust, and it contains ten times more water than any other Martian meteorite found on Earth. It also contains organic carbon. The age of the rock, called NWA 7034, would put its origins in the early era of the most recent geologic epoch on Mars, the Amazonian epoch. While its composition is different from any previously studied Martian meteorite, NASA says it matches surface rocks and outcrops that have been studied by Mars rovers and Mars-orbiting satellites.

“The contents of this meteorite may challenge many long held notions about Martian geology,” said John Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington. “These findings also present an important reference frame for the Curiosity rover as it searches for reduced organics in the minerals exposed in the bedrock of Gale Crater.”

This new class of meteorite was found in 2011 in the Sahara Desert. Designated Northwest Africa (NWA) 7034, and nicknamed “Black Beauty,” it weighs approximately 320 grams (11 ounces). Research teams from the University of New Mexico, the University of California at San Diego and the Carnegie Institution in Washington analyzed mineral and chemical composition, age, and water content.

NWA 7034 is made of cemented fragments of basalt, rock that forms from rapidly cooled lava. The fragments are primarily feldspar and pyroxene, most likely from volcanic activity.

“This Martian meteorite has everything in its composition that you’d want in order to further our understanding of the Red Planet,” said Carl Agee, leader of the analysis team and director and curator at the University of New Mexico’s Institute of Meteoritics in Albuquerque. “This unique meteorite tells us what volcanism was like on Mars 2 billion years ago. It also gives us a glimpse of ancient surface and environmental conditions on Mars that no other meteorite has ever offered.”

There are about one hundred Martian meteorites that have been collected on Earth. They were all likely blasted off the Red Planet by either an asteroid or comet impact, and then spent millions of years traveling through space before falling to Earth.

Researchers theorize the large amount of water contained in NWA 7034 may have originated from interaction of the rocks with water present in Mars’ crust. The meteorite also has a different mixture of oxygen isotopes than has been found in other Martian meteorites, which could have resulted from interaction with the Martian atmosphere.

Scientists say the age of NWA 7034 is important because it is much older than most other Martian meteorites.

“We now have insight into a piece of Mars’ history at a critical time in its evolution,” said Mitch Schulte, program scientist for the Mars Exploration Program at NASA Headquarters.

Most Martian meteorites are divided into three rock types, named after three meteorites; Shergotty, Nakhla, and Chassigny. These “SNC” meteorites currently number about 110. Their point of origin on Mars is not known and recent data from lander and orbiter missions suggest they are a mismatch for the Martian crust. Although NWA 7034 has similarities to the SNC meteorites, including the presence of macromolecular organic carbon, this new meteorite has many unique characteristics.

“The texture of the NWA meteorite is not like any of the SNC meteorites,” said co-author Andrew Steele, who led the carbon analysis at the Carnegie Institution’s Geophysical Laboratory. “This is an exciting measurement in Mars and planetary science. We now have more context than ever before to understanding where they may come from.”

Sources: NASA, Carnegie Institution for Science

This article was updated on 1/4/13.

About 

Nancy Atkinson is Universe Today's Senior Editor. She also is the host of the NASA Lunar Science Institute podcast and works with Astronomy Cast. Nancy is also a NASA/JPL Solar System Ambassador.

Be a Mentor January 3, 2013 at 11:08 PM

This is fascinating. I like to think that previously in another time Mars was not a barren waste land.

Ian McLeod January 3, 2013 at 11:54 PM

Everything changes.

Simon Donaldson January 4, 2013 at 1:03 AM

Please forgive my ignorance on the subject – but how does a piece of rock somehow defy the law of gravity and make its way out the atmosphere of a planet?

Some kind of violent super-volcano eruption? A bodily-impact on the planet surface that rickets some rocks outwards?

Sorry for the dumb-question – I genuinely would LOVE to know, anyone know the answer? ^^

Tim Amato January 4, 2013 at 2:00 AM

Martian meteorites have been blasted off the surface of Mars from impacts of their own from what I’ve been informed. Could it be from a volcanic explosion? Mars has lower gravity and thinner atmosphere than our own Earth allowing for different laws of physics. So you could be making correct assumptions.

Torbjörn Larsson January 4, 2013 at 8:13 AM

I wouldn’t call lower surface gravity or lower density atmosphere (even 2 billion years ago lower than Earth’s) making different laws of physics. But certainly different outcomes. (Say, impact scars look slightly different on different planets because of such factors.)

There is a “transport belt” of material flowing between planets like Mars and Earth, caused by so called hypervelocity impactors.

Here is how it happens, as I remember it from the top of my head from astrobiology class. (I will use Earth as example, as I have the figures in my head.)

Earth has an orbital velocity of ~ 30 km/s. If it catches up with an asteroid that doesn’t coorbit, it can meet it at speed. The average asteroid impact speed as it meets Earth atmosphere is ~ 20 km/s. (Comets, who are falling in from way outside the inner planets, meets at ~ 50 km/s average.)

At the same time the escape velocity, the needed velocity to get away from Earth’s gravity, is ~ 10 km/s.

So if any impactor hits Earth and the impact process launches some rocks at similar speed, it can escape. Let us check this:

Satellites and ISS orbits above ~ 200 km to get away from air resistance. A sufficiently large impactor, say 10 km in diameter, will not be slowed down by the ~ 100 km of denser atmosphere we have in a few seconds. (Smaller impactors may do this, as the compressed air will set up sufficient resistive force. This is why they end up free falling and land with cool insides.)

So a large impactor can hit at hypervelocity. This term means that the impact speed is faster than sound speed in rocks. In air, sound travel ~ 300 m/s. In crystalline rock it can travel ~ 10 times as fast, ~ 2-3 km/s. (And in more homogeneous metals as an iron rod perhaps a factor 2 faster.) But the impactor hits at larger speed.

This means the kinetic energy can’t be transported away efficiently by mechanical means. Instead the impactor and the impacted surface will melt and vaporize, and in the surrounding rock shock waves will occur.

Shock waves will spallate, kick away, material from surfaces. This will happen up to the same velocity as the shock.

If you keep track of the velocity and its loss through all of this, you find that average sufficiently large asteroids will spallate away material above 10 km/s speed.

IIRC when you run models, rocks will be ejected from a planet amounting to about 3-5 % of the (sufficiently large) hypervelocity impactor mass.

Mars orbits outside of Earth, so slower. Maybe ~ 20 km/s? On the other hand it is much less massive, so I believe the escape velocity is merely half Earth’s, 6 km/s (as opposed to 11 km/s). The much lower atmosphere density nowadays means “sufficiently large” asteroids are now much smaller than in our case. And Mars is closer to the asteroid belt.

In any case, the amount of mass coming from Mars to Earth, I believe estimated to ~ 200 kg/year, is supposedly larger than the amount of mass going from Earth to Mars. We haven’t had any sufficiently large impactors in a while, I think.

Simon Donaldson January 4, 2013 at 10:49 PM

A Fascinating Answer – I’m glad to know that others also put their time and effort into explaining something complicated to those that ask.

Thank you

zkank January 4, 2013 at 7:52 AM

I sincerely don’t mean this to sound harsh, but as you’ve already confessed, that really is a dumb question!

I can tell by your post spelling and grammar that you’re not a child, and have made your way somewhat considerably through the education system, but why don’t you crack open some books to educate yourself on astronomy instead of looking for established science answers in blogs, of all places!

Jeez – you could have answered that question with a simple Google search!
Make an effort to get the answers yourself, first!
Much more rewarding, and much more accurate information.

Regarding volcanoes ejecting material from Mars – I’ll only comment because of Tim’s erroneous post.

No volcanoes; impacts are the only cause that sent Martian rocks to Earth.

I3VI5 January 6, 2013 at 1:41 AM

Congratulations, you’re a douchebag.

JM January 4, 2013 at 6:38 AM

Amazing…found in the Sahara Desert. Seems that would be akin to finding a needle in a haystack.

Hans Peter Uhrig January 4, 2013 at 9:46 AM

Interesting!
While the researchers of the above article were focused on the water content and source of the NWA Mars meteorites they also “stumbled across” the richness in organic C and O which supports the findings of another group of researchers looking at the same class of meteorites from Mars recently:

DISCOVERY OF BIOLOGICAL STRUCTURES IN THE TISSINT MARS METEORITE
http://www.panspermia.org/tissintfinal.pdf

Torbjörn Larsson January 4, 2013 at 4:40 PM

Well, I hope you don’t take anything published with Wickramasinghe’s name on it seriously. The man is a pseudoscience transpermia producer. In this case they do the obligatory pattern search for structures and leave it at that.

[As a comparison from Earth, paleontologist Schopf, one of the astrobiology experts that supports NASA, used to do that a lot in the 80's - 90's, but academically acceptable.

However, that type of research and his previous results got rejected one by another, until paleontologist Brazier et al delivered a definite paper on how _not to_ do these things somewhere in the later 00's. You want corroborative evidence from rigorous chemistry tied to the morphology.

Of course, it was a windup for them to present their own candidate for "oldest fossil". :-) It has then been superseeded, I believe, and the subject itself profited from the clearing up.

Now these rigorous standards need to be applied to the area of meteorites as well.]

The SNC meteorites are, as the article says, known for their organic content. Those in turn are known to be created encapsulated in minerals during volcanic processes. ( http://www.space.com/15860-mars-meteorites-life-building-blocks.html ; http://www.universetoday.com/95892/organics-found-in-mars-meteorites-but-nothing-biological/ ):

“Ten of the meteorites possessed complex hydrocarbons — compounds of carbon and hydrogen atoms — encased within grains of crystallized minerals that formed within cooling magma.

“When the minerals crystallized from the magma, they trapped carbon in them, and over time, organic compounds formed within these mineral bottles,” Steele said.”

Hans Peter Uhrig January 7, 2013 at 9:01 AM

So why everybody still wonders how life came into existence if it is so easy? Expanding on that why does everybody think it was only possible on Earth?

By the way the science crews of the “other side of the fence” also use these vague null hypothesis approach – just the other way around claiming that if there is a way for abiogenesis it must be the only resolution. :)

Think about it and have a look at the SEM close-ups of the carbon/oxygen globules in the linked paper without paying attention to the text if you don’t like the authors. Its not about patterns only here but about linked and approved chemical data (see research of the above article).

I wonder too how long the science communities can keep up with the hard skepticism regarding exo-life without ridiculing themselves in the long run.

Michael Roberts January 5, 2013 at 6:19 PM

so for me it seems that scientists go back and forth arguing about Mars and its past, I think mars just got too cold

I3VI5 January 6, 2013 at 1:44 AM

Interesting stuff!
By the way, how do they know this specific rock came from mars?

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