A bug scientist says NASA can stop looking for life on Mars now, because he's already found it.
Entomologist William Romoser, an emeritus professor at Ohio University, says photos taken by the space agency's rovers clearly show there are insects on the red planet.
"There has been and still is life on Mars," he said, presenting his claims at a scientific conference earlier this week in St Louis, Missouri.
"There is apparent diversity among the Martian insect-like fauna which display many features similar to Terran insects that are interpreted as advanced groups - for example, the presence of wings, wing flexion, agile gliding/flight, and variously structured leg elements."
Terran is a word usually found in science fiction to denote an inhabitant of the Earth. But Dr Romoser says there's nothing fictional about his claims.
"An exoskeleton and jointed appendages are sufficient to establish identification as an arthropod," he said. An arthropod is a creature with an exoskeleton, such as a bug, spider or crab.
"Three body regions, a single pair of antennae, and six legs are traditionally sufficient to establish identification as 'insect' on Earth. These characteristics should likewise be valid to identify an organism on Mars as insect-like.
"On these bases, arthropodan, insect-like forms can be seen in the Mars rover photos."
The images include not just fossils, but what he says are living bugs. Some of them he said resemble bees.
"The presence of higher metazoan organisms on Mars implies the presence of nutrient/energy sources and processes, food chains and webs, and water as elements functioning in a viable, if extreme, ecological setting sufficient to sustain life," he added. 'Metazoan' is another term for 'animal'.
Dr Romoser is no hack - he's taught and studied at Ohio University for nearly five decades, publishing a number of books on entomology. But NASA says he simply must be wrong this time.
"We have no scientific data that would support this claim," a spokesperson told tech site CNET. "There is insufficient oxygen to sustain the metabolism of metazoans on Mars. On Earth, animals, especially as complex as these, need lots of oxygen. There are only traces in Mars' atmosphere."
NASA's Curiosity rover has been picking up some weird readings lately. In June, it detected a "startlingly high" spike in methane, a gas that here on Earth is produced through biological processes - New Zealand's dairy industry for example is a large emitter of methane, also a greenhouse gas.
And just last week, it was reported Curiosity has measured huge variations in the amount of oxygen in the atmosphere, which scientists are struggling to explain.
But on average, the Martian atmosphere is only about 0.16 percent oxygen - on Earth, where insects as we know them definitely evolved, it's almost 21 percent.
Dr Romoser said at the very least there's a "solid justification for further study", and hinted his research would spark not just questions about biology, but "social and political" questions too.
NASA's next mission to Mars will launch next year, touching down on the red planet in February 2021. It will be able to look for search for evidence of ancient microbial life, NASA assuming there's none there at the moment but might have been in the past.
