Atmosphere of Mars energy to escape the planet. In this process the light isotope of carbon (C) is most likely to leave the atmosphere. Hence, the carbon dioxide left in the atmosphere would be enriched with the heavy isotope (C). This higher level of the heavy isotope is what was recently found by the "Curiosity" rover that sits on the surface of Mars. The atmosphere of Mars is enriched considerably with the noble gas argon, in comparison to the atmosphere of the other planets within the Solar System. Unlike carbon dioxide, the argon content of the atmosphere does not condense, and hence the
Carbon dioxide in Earth's atmosphere time in 55 years of measurement—and probably more than 3 million years of Earth history." The current concentration may be the highest in the last 20 million years. Carbon dioxide concentrations have varied widely over the Earth's 4.54 billion year history. It is believed to have been present in Earth's first atmosphere, shortly after Earth's formation. The second atmosphere, consisting largely of nitrogen and co2 was produced by outgassing from volcanism, supplemented by gases produced during the late heavy bombardment of Earth by huge asteroids. A major part of carbon dioxide emissions were soon dissolved in water and incorporated in