Pictured: An Ancient Martian? ... Credit Copyright: D. McKay ( NASA / JSC ), K. Thomas-Keprta ( Lockheed-Martin ), R. Zare ( Stanford ), NASA Explanation: Alien! ... The tube-like form on the above highly magnified image is now believed by many to be a fossil of a simple Martian organism that lived over 3.6 billion years ago . ... NASA missions to Mars in the next few years include Mars Global Surveyor and Mars Pathfinder , which may uncover data that help confirm or refute this exciting claim. ...