Since I became the Vatican Observatory’s director I haven’t had much time to spend in the lab, so I was particularly pleased when a scientific paper with my name on it actually appeared in print this month.

For nearly 25 years we’ve been measuring certain basic properties of meteorites, those rocks that have fallen to Earth from the asteroid belt, or the Moon or Mars. One of those properties we measure is heat capacity, which is … well … the capacity of the rock to hold heat.

How much heat does a meteorite give off when it drops one degree in temperature? And how do you measure that? A fellow Jesuit physicist, Fr Cy Opeil, has a lab at Boston College with an elaborate device that can do just that. He’s measured a handful of tiny meteorite slices for us. It’s fabulously accurate, and time-consuming, and expensive.