The pieces were analysed by an international team of scientists that included experts at London's Natural History Museum.
A one kilogram lump of the meteorite measuring about 12 centimetres across is now on display in the museum's The Vault gallery.
Dr Caroline Smith, meteorites curator at the Natural History Museum, said: "Any meteorite that is seen to fall - they're called "fall meteorites" - are particularly interesting because they suffer from very little contamination.
"One of the main things we found was that some of the chemical signatures in this meteorite indicate it must be from quite close to the surface of Mars, or even on the surface."
The meteorite contains large amounts of black glass, created by heat from a shock impact melting rock.
Scientists know that elements found inside the glass cannot have resulted from contamination from Earth.
One of them turned out to be cerium, an element from the Martian surface. The unusual levels of cerium suggested they had been deposited by a leeching process involving water.
Mars Curiosity Pictures
(01 of05)
Open Image Modal
In this image released by NASA on Monday, Aug. 27, 2012, a chapter of the layered geological history of Mars is laid bare in this color image from NASA's Curiosity rover showing the base of Mount Sharp, the rover's eventual science destination. The image is a portion of a larger image taken by Curiosity's 100-millimeter Mast Camera on Aug. 23, 2012. Scientists enhanced the color in one version to show the Martian scene under the lighting conditions we have on Earth, which helps in analyzing the terrain. The pointy mound in the center of the image, looming above the rover-sized rock, is about 1,000 feet (300 meters) across and 300 feet (100 meters) high. (AP Photo/NASA/JPL-Caltech/MSSS) (credit:AP)
(02 of05)
Open Image Modal
In this image released by NASA on Monday, Aug. 27, 2012, an image taken by the Mast Camera (MastCam) highlights the geology of Mount Sharp, a mountain inside Gale Crater, where the rover landed. Prior to the rover's landing on Mars, observations from orbiting satellites indicated that the lower reaches of Mount Sharp, below the line of white dots, are composed of relatively flat-lying strata that bear hydrated minerals. Those orbiter observations did not reveal hydrated minerals in the higher, overlying strata. The MastCam data now reveal a strong discontinuity in the strata above and below the line of white dots, agreeing with the data from orbit. Strata overlying the line of white dots are highly inclined (dipping from left to right) relative to lower, underlying strata. The inclination of these strata above the line of white dots is not obvious from orbit. This provides independent evidence that the absence of hydrated minerals on the upper reaches of Mount Sharp may coincide with a very different formation environment than lower on the slopes. The train of white dots may represent an "unconformity," or an area where the process of sedimentation stopped. (AP Photo/NASA/JPL-Caltech/MSSS) (credit:AP)
(03 of05)
Open Image Modal
In this image released by NASA on Monday, Aug. 27, 2012, An image from a test series used to characterize the 100-millimeter Mast Camera on NASA's Curiosity rover taken on Aug. 23, 2012, looking south-southwest from the rover's landing site. The 100-millimeter Mastcam has three times better resolution than Curiosity's 34-millimeter Mastcam, though it has a narrower field of view. The gravelly area around Curiosity's landing site is visible in the foreground. Farther away, about a third of the way up from the bottom of the image, the terrain falls off into a depression (a swale). Beyond the swale, in the middle of the image, is the boulder-strewn, red-brown rim of a moderately-sized impact crater. Farther off in the distance, there are dark dunes and then the layered rock at the base of Mount Sharp. Some haze obscures the view, but the top ridge, depicted in this image, is 10 miles (16.2 kilometers) away. Scientists enhanced the color in one version to show the Martian scene under the lighting conditions we have on Earth, which helps in analyzing the terrain. (AP Photo/NASA/JPL-Caltech/MSSS) (credit:AP)
(04 of05)
Open Image Modal
In this image released by NASA on Monday, Aug. 27, 2012, a photo taken by the Mast Camera (MastCam) highlights the geology of Mount Sharp, a mountain inside Gale Crater, where the rover landed. Prior to the rover's landing on Mars, observations from orbiting satellites indicated that the lower reaches of Mount Sharp, below the line of white dots, are composed of relatively flat-lying strata that bear hydrated minerals. Those orbiter observations did not reveal hydrated minerals in the higher, overlying strata. The MastCam data now reveal a strong discontinuity in the strata above and below the line of white dots, agreeing with the data from orbit. Strata overlying the line of white dots are highly inclined (dipping from left to right) relative to lower, underlying strata. The inclination of these strata above the line of white dots is not obvious from orbit. This provides independent evidence that the absence of hydrated minerals on the upper reaches of Mount Sharp may coincide with a very different formation environment than lower on the slopes. The train of white dots may represent an "unconformity," or an area where the process of sedimentation stopped. (AP Photo/NASA/JPL-Caltech/MSSS) (credit:AP)
Mike Malin, John Grotzinger, Paul Mahaffy, Chad Edwards(05 of05)
Open Image Modal
Chad Edwards, chief telecommunications engineer for NASA's Mars Exploration Program, far right, explains how an international network of telecommunications relay orbiters bring data back from Mars during a briefing at NASA's Jet Propulsion Laboratory in Pasadena, Calif., Monday, Aug. 27, 2012. Curiosity already has returned more data from the Martian surface than have all of NASA's earlier rovers combined. Relay robotic spacecraft orbiting Mars seen on graphic: NASA's Mars Reconnaissance Orbiter, MRO, and Mars Odyssey ODY. Scientists from left: Mike Malin, imaging scientist for the Mars Science Laboratory, John Grotzinger, MSL project scientist, California Institute of Technology, Paul Mahaffy, NASA Goddard Space Flight Center, and Dr. Edwards. (AP Photo/Damian Dovarganes) (credit:AP)
"This enrichment has happened because of the weathering process you get at the near surface of Mars," said Dr Smith. "Water, or fluids, have picked up the cerium and gone into gaps in the rock."
No-one knows when this occurred, but it would have been some time before the rock was ejected from Mars.
Nitrogen originating from Martian atmosphere was also identified in the black glass.
Findings from the research, conducted by 20 scientists in five countries, appear today in the journal Science.
Lead researcher Professor Hasnaa Chennaoui Aoudjehane, from the Hassan II University in Casablanca, Morocco, said: "The Tissint Martian meteorite found in Morocco is very important because it is so fresh. We have conclusively shown, for the first time, the chemical signatures of weathering processes on Mars."
Dr Smith said scientists on Earth could analyse the rock with a precision not possible using robots such as the rover Curiosity, which recently landed in a Martian crater.
"Meteorites are known as the poor man's space probe," she said.
She added there was absolutely no suggestion of any sign of Martian life in the meteorite.
"I can say hand on heart that people have not found anything indicative of little green men or little green bugs," she said.
In 1996 scientists at the American space agency Nasa claimed to have discovered evidence of fossil microbes in a Martian meteorite from Antarctica known as ALH84001.
Since then other experts have argued that the "bugs" probably have a non-biological origin.