NASA and the European Space Agency (ESA) asked mineralogist Monica Grady to look at recovered pieces of the Hubble space telescope and Eureca satellite. The space agencies wanted to know which caused the most damage - micrometeorites or space debris.

She looked at impact sites on the telescope pieces with an SEM. Using the unique chemical 'signatures' of the objects that caused the impacts, Monica was able to identify them.

The results were surprising. Over one-third of all impacts were caused by space debris: micrometeorites only caused one-tenth. The rest were unidentifiable. There are large amounts of space debris in orbit. Monica has shown that it is a significant problem.