NASA's Curiosity Mars rover is moving on with its ultimate science goal after some recent excitement tapered out.

According to Space.com, Curiosity generated some buzz when it spotted what looked like a thighbone on the surface of the Red Planet. The rover also determined that the "Bonanza King" rock was not suited well enough for drilling.

While Curiosity may have found enough evidence to suggest Mars could have once supported microbial life, complex organisms have still stayed outside the realm of possibility.

"Seen by Mars rover Curiosity using its MastCam, this Mars rock may look like a femur thigh bone," officials at NASA's Jet Propulsion Laboratory (JPL) said in a statement. "Mission science team members think its shape is likely sculpted by erosion, either wind or water.

"If life ever existed on Mars, scientists expect that it would be small simple life forms called microbes. Mars likely never had enough oxygen in its atmosphere and elsewhere to support more complex organisms. Thus, large fossils are not likely."

On Wednesday, the "Bonanza King" rock shifted slightly during drilling preparations, so mission managers chose to move on instead of finding a new target in the area. Curiosity has been on a course to Mount Sharp, a mountain in the middle of the Gale Crater.

Bonanza King was located in the northeastern end of the "Hidden Valley," which curiosity had to avoid due to issues with wheel traction. Curiosity's mission managers are taking a patient and deliberate approach to reaching Mount Sharp.

"We have decided that the rocks under consideration for drilling, based on the tests we did, are not good candidates for drilling," Jim Erickson, a Curiosity project manager at JPL, said in a press release. "Instead of drilling here, we will resume driving toward Mount Sharp.

"After further analysis of the sand, Hidden Valley does not appear to be navigable with the desired degree of confidence... We will use a route avoiding the worst of the sharp rocks as we drive slightly to the north of Hidden Valley."