How can I find out how old I am on another planet?
You would be the same age wherever you were! I assume, though, what you mean is 'how do you work out your age in, say, Mars years or Jupiter years as opposed to Earth years?'. This is actually quite easy. You just need to know how long it takes each planet to orbit the Sun:
Karen was a graduate student at Cornell from 2000-2005. She went on to work as a researcher in galaxy redshift surveys at Harvard University, and is now on the Faculty at the University of Portsmouth back in her home country of the UK. Her research lately has focused on using the morphology of galaxies to give clues to their formation and evolution. She is the Project Scientist for the Galaxy Zoo project.