NASA’s Perseverance rover may have just brought us one step closer to answering one of humanity’s greatest questions: Is there life on Mars? Scientists announced on Wednesday, Sep. 10, that the rover uncovered unusual rocks in a dried-out riverbed that may contain chemical clues linked to ancient microscopic organisms. The discovery reignited global interest in the search for extraterrestrial life, marking a major milestone in NASA’s long-term Mars exploration program.
The discovery was made in Neretva Vallis, a river channel that once flowed into Jezero Crater. Perseverance drilled into reddish, clay-rich mudstones known as the Bright Angle formation and collected its 25th sample. In those rocks, researchers found tiny specks enriched with iron phosphate and iron sulfide—minerals that on Earth often form when microorganisms break down organic matter. Suggesting unique chemical reactions that could have involved biological activity billions of years ago.
“This is the closest we’ve actually come to discovering ancient life on Mars,” said Nicky Fox, NASA’s science mission chief.
She stressed that the evidence is far from conclusive and that more testing is needed before anyone can declare the existence of Martian life, adding that all they can say for now is that one possible explanation is microbial life.
“All we can say is one of the possible explanations is microbial life, but there could be other ways to make this set of features that we see,” Joel Hurowitz, the study’s lead researcher from Stony Brook University, said. “Either way, it’s the best candidate we’ve seen so far.”
The findings were released in the journal Nature, sparking widespread enthusiasm within the scientific community. Nevertheless, scientists not involved in the project have called for caution.
Janice Bishop of the SETI Institute and Matio Parente of the University of Massachusetts Amherst, who was not part of the study, noted that non-biological processes could also explain the findings. Certain mineral formations, they said, can mimic biological patterns which create false positives—a challenge that makes proving life on Mars especially difficult.
“There is no evidence of microbes on Mars today, but if any had been present on ancient Mars, they too might have reduced sulfate minerals to form sulfides in such a lake at Jezero Crater,” Bishop and Parente wrote in an editorial accompanying the study.
The challenge is getting those samples back to Earth. NASA initially hoped to retrieve them in the early 2030s, but increasing costs—now projected at $11 billion—have delayed the mission into the 2040s. The agency is exploring faster and cheaper alternatives, including sending new instruments to Mars for on-site analysis. NASA engineers are also studying whether future landers could retrieve and launch the samples directly from the Martian surface, a task never before attempted.
For now, the 30 samples Perseverance collected remain either stored aboard the rover or stashed on the Martian surface. They sit in time frozen, holding the secrets that could confirm or rule out the possibility of ancient Martian life.