Photos sent from the Mars Rover Curiosity suggested that microbial life once existed on the planet. The photos of the sedimentary rocks have remarkable resemblance to the structures on Earth. The images were taken on the Gale crater, a crater near the northwestern part of the Aeolis quadrangle. According to some researchers few samples need to be brought on the earth to have a core and detailed study in order to confirm the resemblance of these structures with the structures on Earth.
A study published in the journal Astrobiology states that some prominent sedimentary rocks shown in Mars Curiosity photos have a remarkable similarity to structures created by life on Earth.