The Discussion: Christmas in Cydonia and teaching science to children through astronomy education.

The News: Kicking off 2015 we round off the events that concluded 2014: the successful test flight of NASA's Orion capsule; NASA's Mars Science Laboratory pieces together the clues that tell us how Mount Sharp (the mountain Mars Curiosity is exploring) was formed; and science findings from ESA's Rosetta and Philae spacecraft that suggest water was not delivered to Earth by comets like 67P Churyumov Gerasimenko.

The 5 Minute Concept: This month Paul delves into the fundamental nature of our universe. We take a look at the Cosmological Principle, which tells us that the universe and the forces within it are the same wherever we look, and explore huge structures that put strain on this accepted model of cosmology.

The Interview: Ralph & Paul speak with the creators of the 'Essex Space Agency', Matt Kingsnorth and Phil St Pier who are building a high altitude balloon with cameras to photograph the Earth's curved horizon from the edge of space in their Helium Tears project.

Q&A: Listeners' questions via email, Facebook & Twitter take us on a journey into the astronomy issues that have always plagued our understanding or stretched our credulity. This month Ralph & Paul answer:

• Are there Van Allen Belts & Aurora on other planets? Any photos from satellites orbiting other planets in our solar system? Mariecor Agravante in San Diego via twitter.
• Why was the moon so large the other night?Ian Cheale in Cambridgeshire via the Facebook Group.