If they aren't from Mars, they are from a planet exactly like it, scientists concede.
Previously, researchers believed that the mineral might have hinted at an ancient, dry Mars - but researchers at the University of Nevada, Las Vegas (UNLV) believe that it may have formed from another mineral (whitlockite) during the shock of ejection from Mars.
Scientists at the University of Nevada, Las Vegas analyzed a mineral called merrillite found in Martian meteorites, according to a study published Monday in the journal Nature Communications.
Researchers are still trying to get a handle on that Martian "water budget".
The Valles Marineris is shown in this undated composite image of the surface of the planet Mars.
An artist's impression of what Mars might have looked like with water, when any potential Martian microbes would have evolved. However, what could really prove these theories is a piece of Mars itself.
The crux of the study is based on Mars mineralogy. "Unfortunately, these meteorites have all experienced shock from being ejected of the Martian surface during impacts". Even still, those conditions lasted for only 100 billionths of a second. They are also believed to have come from only a few regions on Mars, and were likely ejecta created from impact events. This cause the once wet mineral to turn into a dry merrillite.
Still, there's only so much that can be learned from lab experiments and studies of Mars meteorites, study team members said. Scientists, with the help of Berkeley Laboratory, California conducted simulations on an ancient Martian mineral that has nosed out in Martian meteorites.
For the sake of their study - titled "Shock-Transformation of Whitlockite to Merrillite and the Implications for Meteoritic Phosphate", which appeared recently in the journal Nature Communications - the global research team considered another possibility.
For the study, researchers generated a synthetic version of the Martian mineral called whitlockite and conducted some shock-compression tests on the mineral samples. Whitlockite contains hydrogen atoms, merrillite does not.
The only problem is, most of the source material for merrillite-rich Martian meteorites found on Earth is buried more than a half-mile beneath the surface of the Red Planet. "If true, it would indicate more water in the Martian past and the early Solar System". And last November, NASA reported a huge underground body of water ice on Mars, in one area. Whitlockite can be dissolved in water and contains phosphorous, a crucial element for life on Earth.
"As far as life goes, our results are very favorable for the possibility - but we need more data". "Had there ever been an environment that enabled a generation of life on Mars?"
And sample returns are certainly on the horizon.
Or go to Mars, collect some rocks and bring them home. On Earth, wherever water is found, life is also found.
These missions are scheduled to launch the summer of 2020, when the planets will be at their closest again.