The measurements by Curiosity rover of NASA, the most advanced spacecraft to land on Mars, the Red Planet, re-instated the fact, in the month of July 2013, that the planet was composed of mostly carbon dioxide and a few other gases. These measurements match very closely with the findings of the Viking which had revealed about this in late 1970s. Apart from this, the scientists had also revealed the same earlier with clues from the Martian meteorites that fell on Earth.
It was revealed lately that the atmosphere of Mars was mostly dominated by carbon dioxide. However, it was surprising that earlier Viking had found that nitrogen was the second most abundant gas to be found in Mars’s atmosphere. But, measurements from Curiosity found that nitrogen as well as argon was nearly equal in abundance on the Martian air. The differences in the findings could be because of the use of different tools to collect the samples from the atmosphere.
NASA’s Goddard Space Flight Center’s Paul Mahaffy, the in-charge of Curiosity's air sampling experiments explained that despite the difference in findings of Viking and Curiosity, the notion that Mars had lost almost all the original atmosphere to space, is very much clear. This has what led to the change of this planet into the cold desert.
The Curiosity Rover of NASA is the nuclear-powered, six-wheel rover which landed in ancient crater near the equator of Mars in 2012. The study however did not explain anything about the presence of Methane on Mars.
In 2012, the team of Curiosity reported that there was no definitive aroma of Methane near its landing site. Since that time, a lot of air samples have been collected by the rover. In context with this, NASA has already decided to launch a Mars-orbiting spacecraft in order to solve the mystery of Methane on Mars.
This new rover will be called Maven and it will target the Martian atmosphere. Scientists will explore whether Methane actually exists on Mars or not and will also find out about its abundance. Apart from this, Maven will also find out whether it varies year after year. The mission chief scientist of this is Bruce Jakosky of the University of Colorado.