NASA’s Curiosity Rover Confirms Martian Meteorites on Earth Originated From Mars

Latest analysis of the Martian rock sample conducted by NASA's Curiosity rover confirms that the meteorites found on Earth did originate from the Red Planet. The latest research also provides a new way to rule out Martian origins of other meteorites.

The  study results are based on the new analysis of the Mars' atmosphere by Curiosity Rover, the largest robotic rover sent by NASA to Mars.

The researchers determined the origin of the meteorites discovered on Earth using Curiosity's Sample Analysis at Mars (SAM). The instrument SAM on Curiosity accomplished high precision count of two forms of argon gas -Argon 36 and Argon 38. These lighter and heavier forms of argon gas are seen naturally existing throughout the solar system.

On Mars, the ratio of light to heavy argon is distorted as plenty of the planet's original atmosphere was lost to space. The Red Planet currently has high levels of heavier Argon-38 as the lighter Argon left the planet since it easily rises to the top of the atmosphere and requires less energy to escape

According to the researchers, argon is the clearest and strongest signature of the Martian atmospheric loss as it is chemically inert and does not react with the Martian surface.

Based on the gas bubbles trapped inside the Martian meteorite, the scientists had earlier summed up the Martian argon ratio between 3.6 and 4.5 (that is 3.6 to 4.5 atoms of Argon-36 to one atom of Argon-38). In the 1970's, measurements made by NASA's Viking landers placed the Martian atmospheric ratio to arrange of 4-7. But the correct argon ration provided by the new SAM direct measurement on Mars is 4.2.

"We really nailed it," said Sushil Atreya of the University of Michigan, Ann Arbor, the lead author of a paper, according to a news release. "This direct reading from Mars settles the case with all Martian meteorites," he said.

By understanding the atmospheric loss of the Red Planet, the scientists can better understand how the Red plan converted from a water-rich planet to a dry, cold and inhabitable planet.

"Other isotopes measured by SAM on Curiosity also support the loss of atmosphere, but none so directly as argon," Atreya concluded.

The findings were published in the Geophysical Research Letters, a journal of the American Geophysical Union.