Space between the stars looks empty, but it's filled with a vast, thin soup of gas and dust called the interstellar medium — the raw material of new stars and the recycled remains of stars that have already died. This episode explores what this material is made of, how molecular clouds collapse to form stars, and how astronomers use the dimming and reddening of distant starlight to map material they can't see directly.

You'll come away understanding what fills the space between stars, how stellar nurseries form inside molecular clouds, why the elements in your own body were forged inside long-dead stars, and how astronomers detect and measure a medium that gives off almost no visible light of its own.

Talking Science is sponsored by Kinsoft. Visit www.kinsoft. ...