The science highlights that defined 2015.

New Horizons has revealed that the surface of Pluto has somehow been refreshed, activity that may be tied to an underground ocean or ice volcanoes.

Pluto is back to being everyone’s favourite planet that’s not a planet.

Pluto has been jilted by astronomers as often as it has been serenaded – now is its time to shine.

A Nasa spacecraft has sailed past Pluto, capping a journey of 4.88-billion kilometres that began nine and a half years ago.

When New Horizon left, Pluto was still classified as a planet. Now the dwarf planet will divulge its secrets as the probe whizzes past at 50 000km/h.