Mars may once have been the home to an entire alien race before a cataclysmic collision destroyed the atmosphere and wiped out all signs of life four billion years ago, the Guardian Express reported.

Scientists at NASA's Jet Propulsion Laboratory (JPL) believe that, based on data collected from the Curiosity rover, that life likely existed on Mars billions of years ago. However, they believe a massive collision with a space body the size of Pluto or catastrophic volcano eruptions caused the planet's air to shrink and disappear, killing any life forms on the planet.

Dr. Chris Webster, of the JPL, was the lead author of the study.

"As Mars became a planet and its magma ocean solidified, catastrophic outgassing occurred while volatiles were delivered by impact of comets and other smaller bodies," he said. "Solar wind and the possible impact by a Pluto-sized body is thought to have stripped much of the initial early atmosphere from the planet, and since then the atmosphere has developed as a balance between volcanic injection and loss to space."

The study suggested that the atmosphere on Mars was once much denser and water likely existed, leading scientists to believe oxygen existed on the red planet before it did on Earth.

Researchers found samples of clay minerals, sulfate and other chemicals in drilled bedrock from the planet's surface. They were also able to find traces of hydrogen, carbon and oxygen in rocks collected by Curiosity.

"A fundamental question for this mission is whether Mars could have supported a habitable environment," said Michael Meyer, lead scientist for NASA's Mars Exploration Program. "From what we know now, the answer is yes."

Further data expected from the rover will help scientists reconstruct the evolution of Mars' climate, NASA said. That will allow scientists to better determine if, in fact, the climate could have ever sustained life.

Curiosity is heading toward Mount Sharp, the mountain at the center of the rover's landing spot, the Gale Crater. The mountain is believed to contain answers to many of the red planet's most perplexing and mysterious secrets.

John Grunsfield, a NASA official, said the new data and subsequent findings made him "feel giddy."