Heather Couper investigates the mysteries of our solar system and beyond.

01The Hunt For Planet X20041229The solar system's outer edge is cold and unexplored.
Could another planet lurk beyond Pluto?
02To Catch A Comet20050105The lure of the comet is centuries old.
Helen meets those who hope to land a probe on one of them.
03 LASTOther Worlds20050112Heather follows the search for planets circling other stars.