Scientists in Egypt have found a footprint from a human ancestor that may be as old as 2 million years! The footprint was most likely made in mud that hardened into rock. This imprint is considered a fossil and its exact age can be determined by looking at plants found in the same rock. Scientists can use Carbon dating, which takes advantage of a rare radioactive isotope of Carbon called Carbon 14.
Can you imagine someone finding your footprint in 2 millions years?
http://www.cnn.com/2007/TECH/science/08/20/egypt.footprint.reut/index.html
http://www.msnbc.msn.com/id/20360598/
