What is the spread of chemical isotopes on other planets?

Pamela wants to know whether the distribution of chemical isotopes is the same on other planets as it is on Earth. Take carbon, for example, 99% of which is carbon-12 on Earth while 1% is carbon-13? To find the answer, James Tytko asked Xander Byrne from the University of Cambridge's Institute of Astronomy... Like this podcast? Please help us by supporting the Naked Scientists