Among many of the National Aeronautics and Space Administration's (NASA) missions, one is to determine whether or not the organic and mineralogical makeup of Mars can indicate a sign that there was life on the planet millions and billions of years ago.

And now, four years after NASA's Curiosity rover landed on the Red Planet, an answer is within reach.

On August 6, 2012, the Curiosity rover landed successfully on Mars and since then, it has managed to help the scientists back on Earth on their quest to understand its history. The rover landed on what is known as the Gale crater.

"Aeolis Mons, known informally as Mount Sharp, is the central mountain within Gale crater where Curiosity landed," said Deputy Project Scientist Ashwin Vasavada in an e-mail correspondence with Universe Today. "It was chosen as Curiosity's landing site because the mountain and the nearby plains have evidence for ancient liquid water in the form of channels and debris fans, as well as minerals that form when liquid water interacts with rock."

Gale crater was believed to be once filled with water, as indicated by the sedimentary deposits. To better understand what Mars could've looked like billions of years ago, NASA's Curiosity rover began drilling into Mount Sharp on September 24. It will then send the images of the drill back over to NASA's Jet Propulsion Laboratory (JPL), and it will undergo analysis to determine its makeup and properties.

So far, the lower layers of Mount Sharp indicated that Mars once had water-rich "ancient environments." The Curiosity rover will continue to go higher up and the same analysis will be given to each sample in hopes of creating a better image of how Mars looked like before it became the cold and dry place it is today.

"The team also is searching for additional evidence of organic molecules that would help them understand whether the raw ingredients of life were present and how they degrade over time," said Vasavada. "The degradation is important to understand for the M2020 Mars rover mission that will search for signatures of ancient microbial life."

Aside from its growing pile of responsibilities, the Curiosity rover and the team behind is also monitoring the weather, climate, and atmosphere of Mars to better understand its meteorology.

Watch: Curiosity Rover Report (August 5, 2016): Four Years on Mars