A bug expert who claims to have found evidence of insects on Mars has fallen victim to a phenomenon called pareidolia, a rival bug expert has claimed.
Earlier this week entomologist William Romoser, an emeritus professor at Ohio University, presented evidence he said showed there are fossilised and living bugs on the red planet. He showed off photos taken by NASA rovers appearing to show shapes that resembled insects here on Earth.
"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," he told a scientific conference.
"On these bases, arthropodan, insect-like forms can be seen in the Mars rover photos."
But insect evolution specialist David Maddison of Oregon State University says Dr Romoser's eyes are deceiving him.
"I, personally, have pareidolia with respect to insects, beetles in particular," he told space.com.
Pareidolia is the scientific term for seeing things that aren't there. A famous example is the so-called face on Mars - a 1976 photograph of the Cydonia region appeared to show a 2km-wide human face staring into space. High-resolution photos taken in the 2000s proved there was no such face.
"Through the years I have built into my brain a pattern-recognition system for picking out beetles," he said, acknowledging how easy it is to fall victim to pareidolia - particularly when there are no beetles around.
"My eyes don't naturally get drawn to the real beetles, instead latching on to whatever beetle-like blob is out in the landscape."
That's what he says has happened to Dr Romoser.
"It is vastly more parsimonious to presume the blobs are simply rocks."
NASA has rubbished Dr Romoser's claims, pointing out there's not enough oxygen in Mars' atmosphere to support Earth-like bugs.
Its next mission to the red planet will include tools that will search for evidence of past microbial life - not live bugs.
