The primary gas found in the atmosphere of Mars is carbon dioxide (CO2), which constitutes about 95.3% of its thin atmosphere. Other gases present include nitrogen, argon, and traces of oxygen and water vapor. The Martian atmosphere is considerably less dense than Earth's atmosphere, making it challenging for humans and most life forms to survive without assistance. The high concentration of carbon dioxide is significant for scientific research, as it impacts potential future colonization efforts and the search for signs of past or present life on the planet. It also plays a role in understanding Martian climate and geology.