But the image managed to furrow the brows of researchers too, for included is its sweep of the Martian landscape at Meridiani Planum was a small object that looked remarkably like a set of bunny ears.

"It's obviously something from the spacecraft," said Jeff Johnson, part of the Mars rover's panoramic imaging team and a scientist with the United States Geological Survey's astrogeology team. "It could be part of the airbags, or any number of bits of material."

Johnson's money, though, is on the airbags.

The detection of the bunny ears-shaped object and the subsequent lighthearted investigation into what it might be was a good practice of what Johnson calls "change detection," the practice of looking for changing conditions on Mars over time. A similar, and more serious, study is being conducted by Mars Exploration Rover (MER) researchers in an attempt to detect dust devils swirling around the red planet, as well as study the accumulation of dust on the rover itself.

But it was the "bunny ears" that caught the public's eye and nearly forced MER scientists to explain it to the public. The object, which is about two inches (five centimeters) long, first appeared in Opportunity's mission success panorama that drew massive attention from the public when it was released by NASA officials at the Jet Propulsion Laboratory (JPL), which is managing the mission.

"[JPL] was flooded with e-mails and they started pleading for somebody to look into it," Johnson told SPACE.com. It was Johnson who was later appointed to hunt down the "bunny."

After analyzing Opportunity's first panoramic image, Johnson tried to retake the picture at a higher resolution only to find out the object had moved. In early navigation camera images, taken the day Opportunity landed, the object was further away, leading Johnson to conclude it was blowing toward the rover lander. Once the rover had rolled off it's landing platform, the "bunny" was seen again, this time underneath the egress landing platform where a light Martian breeze had apparently blown it.

Rob Manning, JPL's lead engineer for MER entry, descent and landing, said there are several possibilities for what the object is, none of them alien in origin. It could be a piece of felt insulation, or airbag material, or cotton insulation, but it is certainly not part of the parachute, which is apparent in its yellow color, Manning added. The parachute is composed of blue, undyed nylon and red dyed nylon.

The "bunny" object does, however, appear to be the same color as the lander's airbags, Johnson said.

This isn't the first time an unknown object has piqued the interest of Mars mission ground controllers.

In the 1997, scientists with the Mars Pathfinder team were puzzled over an object they called "Pinky" sitting in front of the rock target Yogi. While never conclusively identified, the yellowish object was most likely a piece of Kapton tape adhesive used on the Pathfinder mission.

"So it's not unprecedented," Johnson said.