In search of Planet X

Mysteries of Science by Fun Kids

Feb 28, 202522:44Kids & family

Ciaran and Dan look at what makes a planet in this classic episode of Mysteries of Science, and whether there's a mysterious extra planet – Planet X – just beyond Neptune, lurking in our cosmic neighbourhood.

Related Episodes

Continue listening to more episodes from Mysteries of Science.

How did everything begin?

Aug 14, 2026 - 23:45

Dan and Michael explore the biggest mystery of them all: how did everything begin? Around 75 years ago, B...

Feeling lucky?

Jul 17, 2026 - 22:41

Are you a lucky person? Do you have a lucky number, a lucky shirt, or a favourite pair of lucky pants? In...

Fairies and other amazing hoaxes

Jun 18, 2026 - 28:12

We're in the archives for another episode of Mysteries of Science. In our first of season three, released...

The Ice Mummy

May 22, 2026 - 19:46

Two hikers stumble upon something in the ice: a mummy. Called, Ötzi, over the next few days, the mum...

The Truth About Dragons

Apr 23, 2026 - 24:21

Dan and Ciaran open an archive case: Are dragons real? Why do stories of fire-breathing, winged beasts ap...

What came first, the chicken or the egg?

Mar 27, 2026 - 20:35

This special episode is packed with real experts answering the burning questions sent in by you, our curi...

Where's Bigfoot?

Feb 27, 2026 - 30:10

In this monster-sized episode, Dan and Ciaran lace up their hiking boots to probe one of North America's...

Deepfakes

Jan 30, 2026 - 19:48

Can you believe everything you see and hear online? Dan and Michael navigate the fascinating and unsettli...