1. MERCURY This is the first planet from the Sun we humans call Mercury. No not the big yellow ball or even the little black smudge on the left. Mercury is that little dot in the middle. This is a picture of it crossing the sun in 2006. Many many objects in space have crashed into it over the years leaving it heavily cratered just like the Moon. This is the Caloris Basin – one of the largest impact craters in the solar system. It is surrounded by mountains two kilometers high. The colours in this picture, from 2008 when we flew a space probe there, were enhanced to show the different stuff (chemicals and minerals) that make up the planet. Because it’s the closest planet to the sun we often think of it as small burning ball – but here it looks like a calm moon.