(Fox News) It was a complete unknown — it was a rolling stone.

A mystery rock that appeared before NASA’s Opportunity rover in late January — and bore a strange resemblance to a jelly donut — is no more than a common piece of stone that bounced in front of the cameras, NASA said Friday.

The strange rock was first spied on Jan. 8, in a spot where nothing had sat a mere two weeks earlier. Dubbed “Pinnacle Island” by NASA scientists, it was only about 1.5 inches wide. But the rock’s odd appearance — white-rimmed and red-centered, not unlike a jelly donut — made many sit up and take notice.

Now researchers with NASA’s Jet Propulsion Laboratory at the California Institute of Technology have finally cleared up the mystery.

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