Mars mystery rock 'looks like a jelly doughnut'

What's that red jelly doughnut-shaped thing doing on the red planet?

It's like nothing we've ever seen before.- Steve Squyres, lead Mars Exploration rover scientists

That's what befuddled NASA engineers are asking themselves, after the Mars rover Opportunity snapped photos of a mysterious rock they say materialized recently in front of the automated explorer.

"It looks white around the edge in the middle and there's a low spot in the centre that's dark red," lead Mars Exploration rover scientist Steve Squyres told scientists last week at a Jet Propulsion Laboratory anniversary event.

"It looks like a jelly doughnut."

It's also about the size of one of the ringed pastries.

Images captured 12 Martian days before the strange sighting show an empty outcrop. Then, according to Squyres, the rock "just plain appeared" in front of Opportunity's field of vision.

'Total surprise'

Squyres said the rovers have never rolled over that spot.

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Of all the stunning images fed back to Earth so far from the Martian surface, the discovery of this rock now named Pinnacle Island was perhaps the most startling.

"It was a total surprise," Squyres said. "We were like, 'Wait a second, that wasn't there before, it can't be right. Oh my God! It wasn't there before!'"

When Opportunity's instruments took readings and measurements of the weird celestial object, the engineerswere even more puzzled by data they received about the composition of what Squyres described as "the jelly" filling.

"It's like nothing we've ever seen before," he said. Its very high in sulphur, its very high in magnesium, its got twice as much manganese as weve ever seen in anything on Mars."

2 theories

Although Squyres said NASA scientists have been arguing about what this all means, he said two prevailing theories have emerged about how the doughnut ended up in Opportunity's path.

One possibility is the wheels of the rover may have flicked the object, flinging it a metre or two away. Another is that "a smoking hole" emerged somewhere on the planet's surface after a meteor struck the area.

He believes the likely explanation is the rock was displaced by Opportunity's movements.

One way or another, Squyres said the mysteries of Mars continue to fascinate researchers.

Thats the beauty of this mission," he said. "What Ive realized is that we will never be finished. There will always be something tantalizing, something wonderful just beyond our reach that we didnt quite get to and thats the nature of exploration.