NASA's Mars Curiosity examined the Martian atmosphere recently in the month of October, 2013 and it confirms that some meteorites that have dropped to Earth are really from the Red planet.
The new measurement of the inert gas argon in Mars's atmosphere by NASA's Curiosity provides an evidence of the origin of Mars meteorites. The new measurement is a high precision count of the two forms of argon - Argon 36 and Argon 38 which were measured by the Sample Analysis at Mars (SAM) instrument on-board the rover. These two isotopes of Argon exist naturally throughout the solar system. The lighter form of Argon was taken away more readily because it rises to the top of atmosphere more easily and requires less energy to escape. This has left Martian atmosphere enriched with heavier isotope of Argon (Argon 38). The correct Argon ratio measured by SAM is 4.2. One of the reason scientists are so interested in the argon ratio in the Martian meteorites is that it was - before Curiosity -- the best measure of how much atmosphere Mars has lost since the Red planet's wetter, warmer days billions of years ago. Figuring out the Mars's atmospheric loss would enable us to better understand how Mars transformed from a once water-rich planet like Earth into today's drier, colder and less habitable world.
While argon makes up only a tiny fraction of the gas lost to space from Mars, it is special because it's a noble gas. That means the gas is inert, not reacting with other elements or compounds, and therefore a more straightforward tracer of the history of the Martian atmosphere.
"Other isotopes measured by SAM on Curiosity also support the loss of atmosphere, but none so directly as argon," said Atreya. "Argon is the clearest signature of atmospheric loss because it's chemically inert and does not interact or exchange with the Martian surface or the interior. This was a key measurement that we wanted to carry out on SAM."
The Curiosity measurements do not directly measure the current rate of atmospheric escape, but NASA's next mission to Mars, the Mars Atmosphere and Volatile Evolution Mission (MAVEN), is designed to do so. As part of this mission, NASA has launched the MAVEN on 18th November, 2013. More details of NASA's MARS MAVEN Mission.
The new measurement of the inert gas argon in Mars's atmosphere by NASA's Curiosity provides an evidence of the origin of Mars meteorites. The new measurement is a high precision count of the two forms of argon - Argon 36 and Argon 38 which were measured by the Sample Analysis at Mars (SAM) instrument on-board the rover. These two isotopes of Argon exist naturally throughout the solar system. The lighter form of Argon was taken away more readily because it rises to the top of atmosphere more easily and requires less energy to escape. This has left Martian atmosphere enriched with heavier isotope of Argon (Argon 38). The correct Argon ratio measured by SAM is 4.2. One of the reason scientists are so interested in the argon ratio in the Martian meteorites is that it was - before Curiosity -- the best measure of how much atmosphere Mars has lost since the Red planet's wetter, warmer days billions of years ago. Figuring out the Mars's atmospheric loss would enable us to better understand how Mars transformed from a once water-rich planet like Earth into today's drier, colder and less habitable world.
While argon makes up only a tiny fraction of the gas lost to space from Mars, it is special because it's a noble gas. That means the gas is inert, not reacting with other elements or compounds, and therefore a more straightforward tracer of the history of the Martian atmosphere.
"Other isotopes measured by SAM on Curiosity also support the loss of atmosphere, but none so directly as argon," said Atreya. "Argon is the clearest signature of atmospheric loss because it's chemically inert and does not interact or exchange with the Martian surface or the interior. This was a key measurement that we wanted to carry out on SAM."
The Curiosity measurements do not directly measure the current rate of atmospheric escape, but NASA's next mission to Mars, the Mars Atmosphere and Volatile Evolution Mission (MAVEN), is designed to do so. As part of this mission, NASA has launched the MAVEN on 18th November, 2013. More details of NASA's MARS MAVEN Mission.
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