Some scientists think that this unassuming image could be evidence of primitive life on Mars. A scanning electron microscope took this image, which shows an unusual tube-like structural form found in the meteorite ALH84001, which was located in Antarctica in 1984. The meteorite is believed to be of martian origin. Scientists are trying to determine whether the tube-like form — which is less than 1/100th the width of a human hair — could be fossil evidence of primitive life on Mars from 3.6 billion years ago.