An international team of researchers say they've found evidence of biological activity inside a meteorite that fell to Earth from Mars three years ago--in other words, possible evidence that there was once life on the red planet.
But other scientists aren't convinced.
The meteorite in question is the "Tissint" specimen, which famously fell on the Moroccan desert on July 18, 2011.
As the team of researchers--including scientists in China, Japan, Germany, and Switzerland--report in a new paper, chemical, microscopic, and isotope analyses show traces of organic carbon within tiny fissures in the space rock, and that the carbon had to have been deposited before the rock left Mars. Just check out the video above describing the research.
“I’m completely open to the possibility that other studies might contradict our findings," Dr. Philippe Gillet, director of the EPFL Earth and Planetary Sciences Laboratory in Lausanne, Switzerland and a co-author of the paper, said in a written statement. "However, our conclusions are such that they will rekindle the debate as to the possible existence of biological activity on Mars--at least in the past."
And contradiction wasn't long in coming.
As Dr. Marc Fries, a scientist with NASA's curation office at the Johnson Space Center in Houston who was not involved in the meteorite research, told The Huffington Post in an email, "The research group claims that this carbonaceous material is evidence of past life on Mars. I do not agree, and it is not the current consensus of the scientific community that their claim is valid."
Fries said the meteorite could have been contaminated with carbon from terrestrial sources, even if the carbon did come from Mars.
"A biological origin is not the only possible explanation for the carbon found in Tissint," he said in the email. "Other possibilities include volcanic and/or hydrothermal activity on Mars which could permeate Tissint with carbon-bearing fluids... Regardless of whether this particular meteorite contains evidence of life, the implications are more complicated than any simple yes or no answer to whether there is or was life on Mars."
The study was published online in the journal Meteoritics and Planetary Science on November 26, 2014.