Could there be life on Mars? That's the question that's been bugging scientists ever since the possibility of the Mars being the next conceivable life-sustaining planet in our solar system arose. It seemed as if there was a good chance to find life through evidence of what appeared to be a cavern on Mars, but that wasn't the case.

What seemed to be the image of a cavern taken by NASA's Mars Reconnaissance Orbiter last May 5, 2007, was merely a deep pit crater similar to the ones in Hawaii when underground lava drains away and collapses the overlying rock, forming a well-like formation.

A visual overview taken last August 8 using the High Resolution Imaging Science Experiment camera (HiRISE), showed no evidence of a wall or floor that could indicate the opening to a cavern. This was rather disappointing since caves are often good places to search for life, especially on Mars where they could provide protection from the sun's ultraviolet radiation.

Scientists, however, have designed small spherical robots which could explore such deep "lava tubes." Who knows? There may still be a chance to see a Martian or two after all of this is done.