Aussie dog sniffs out possible life on Mars

While the United States and Britain have invested millions in robot rovers to explore Mars, history may yet record that an Australian dog named Tamarind helped confirm there was life on the Red Planet.

While five probes - including two robot rovers - explore Mars, a Sydney scientist's pet dingo-kelpie cross may have found the evidence so many have been seeking.

When US space agency, Nasa, announced in 1996 that a meteorite recovered from Antarctica appeared to contain fossils of ancient Martian bacteria, there were sceptics.

The rock, blasted off Mars 16 million years ago, fell to Earth 13,000 years ago. Inside it were chemical structures that looked like the work of organisms.

But the sceptics argued that one of the structures could form only at very high temperatures -- far too hot for life.

Now two Australians, Tony Taylor, from the Australian Nuclear Science and Technology Organisation, and Queensland University's Professor John Barry, say they have found an identical structure in dozens of different bacteria thriving in the ooze around Queensland's Moreton Bay.

To find them, Dr Taylor took along his dog, Tamarind.

"She's my research assistant," he told the Sydney Morning Herald newspaper, adding he had taught her to sniff out sediments where the right bacteria lived.

"The stuff smells like sewage."

After Tamarind was set loose she veered off the road, into the bush and five minutes later came back covered in mud.

When Dr Taylor examined 82 bacteria from the spot the dog found, and two other nearby sites, one of them a golf course, he discovered 11 characteristics also found in the alleged Mars fossils, including the structure other scientists claimed could only form under scorching heat.

"That is an extraordinary match," he said.

"Our research shows that the structures found in the Nasa meteorite were more than likely made by bacteria present on Mars four billion years ago, before life even started on Earth."

A biophysicist with the nuclear research centre, Dr Taylor said the problematic structure, resembling "cartilage around tiny backbone discs and vertebra", had never been studied in fine detail in earthly bacteria because electron microscopes had insufficient resolution.

The tiny specimens shook under the powerful electron beams.

"People have been blowing their specimens apart."

But he found a way, with the help of ultraviolet light, to steady the organisms.

He initially looked at Moreton Bay because he suspected the bacteria he was hunting would prefer the region's iron-rich alluvial sediments, resembling the iron-rich surface of Mars. But the bacteria are probably found "almost everywhere" on Earth.

Since the Mars rock that fell over Antarctica may be up to 4.5 billion years old -- older than life on Earth -- our world may have been seeded with life transported aboard meteorites from the red planet.

Dr Taylor forecast that while the sceptics would not give up, "they will go quiet".

But Malcolm Walter, director of Macquarie University's Centre for Astrobiology, remained a sceptic yesterday.

"That's putting it mildly," he said, warning that just because something looked like life did not mean it was once alive.

"It would be very interesting if they have seen these structures in bacteria, but it would be far from convincing," said Prof Walter, who conceded that he had not yet read the scientists' full report.

The scientists' findings, crediting Tamarind's work, were included in the latest edition of the Journal of Microscopy, which was released today.

- NZPA