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The rover drilled into Martian rocks and discovered evidence of nitrates, which are essential compounds to the building blocks of life.
"The discovery adds to the evidence that ancient Mars was habitable for life," NASA said in a blog post.
Despite the finding, the space agency said "there is no evidence to suggest that the fixed nitrogen molecules found by the team were created by life."
The nitrates are believed to be ancient and likely came from meteorite impacts or lightning events, according to NASA, which was also pointed out that the surface of Mars is currently inhospitable to known life forms.
Curiosity has also found signs other elements needed for life once existed on the red planet, including liquid water and organic matter, which were located in the Gale Crater billions of years ago, according to NASA.