Hardy moss piglets may have colonised the moon

The colony of hardy bugs that recently crash-landed on the moon, were almost certainly not the first.

Microscopic creatures known as moss piglets or tardigrades, were on board the lander that crashed into the moon in April. Yet, an astronomer says it is likely that others got there first. Picture: Supplied

They were supposed to be the moss piglets who boldly went where no moss piglet had gone before.

Alas, an astronomer has said that the colony of hardy bugs that crash-landed on the moon in April, hailed this week as noble emissaries of the Earth, were almost certainly not the first.

Instead, contamination from lunar landers, astronaut waste and even asteroids makes it likely that they will be welcomed to Earth’s satellite by other eight-legged compatriots who made the same journey long ago. Lunar life may not be as rare as we think.

An Israeli lunar lander crashed into the moon last April. On board were thousands of microscopic creatures known as moss piglets or tardigrades. These are one of the oddest organisms known to biology.

A millimetre long and with a sphincter-shaped face, they are renowned for their ability to survive in environments that would kill almost any other creature. Scientists have shown that they can resist temperatures as high as 150C and as low as -200C. They can also live almost indefinitely in a kind of suspended animation.

Although the Israeli craft failed to land softly as planned, Nova Spivack, who led the mission, said that the tardigrades may not have cared.

“We believe the chances of survival . . . are extremely high,” he said. His announcement was greeted by speculation that the moss piglets had taken one giant leap for hamkind.

Caleb Scharf, director of the Columbia Astrobiology Center, said that it was plausible that the creatures had survived. This was less remarkable than many thought, he added. The hardiness of the tardigrades means that it is highly likely others are already there.

“We know that our efforts to sterilise spacecraft are imperfect,” he wrote in Scientific American. “We know that human spacefarers are an enormous potential cross-contamination problem. On the Moon there are already about 100 baggies of, well, astronaut poop from the Apollo landings.”

We need not necessarily feel depressed that humankind has already contaminated a pristine rock though. Such is the resilience of creatures like the tardigrades that Professor Scharf thinks it likely that others got there first. Large asteroid impacts, of the kind that periodically hit the Earth, tend to throw up huge chunks of surface material.

“It appears that microbial life and tough organisms like tardigrades have a decent chance of withstanding the pressure and temperature extremes during these shockingly violent launches,” he said.

This means that the Moon may be only one of their outposts.

“Nature has been busy cross-contaminating worlds for the past 4 billion years,” he said. “Hardy critters like tardigrades have likely already been deposited far beyond the Earth.”

The Times