Opportunity's Microscopic Imager found this intriguing object, looking more like Rotini pasta. Its odd shape has stirred up Mars researchers, both inside and outside of the NASA Mars Rover Exploration team. Whether or not this object is related to biology has prompted a variety of views.
[Looks like it could be some form of bacteria currently dubbed spirochete - http://www.ucmp.berkeley.edu/bacteria/spirochetes.html. But I don't know what magnification that pic was taken at....probably too big to be a bacteria:) - Nano]