What is the typical size of a visible shooting star? How big must it be to make it to earth?
Most of the meteoroids which enter the Earth's atmosphere are very small - just a few milligrams each. Anything above a few kilograms should make it to the ground. Obviously this depends on the composition. I found a reference to a book on all the known meteorites by Vagn F. Buchwald which might be able to be more precise - perhaps you could try looking at that if you can find it.
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.