My first night out was spent trying to capture images of Jupiter. By combining my usual wildlife lens (EF 100-400L) with a 2x convertor I was able to produce a passable image by stacking multiple exposures. I was pretty excited that I managed to capture the four moons as well as Jupiter itself. The picture below shows the shot I captured alongside an image generated by the Stellarium planetarium software.
Canon EOS 7D, multiple exposures
Canon EOS 7D - 10mm. 30s @ f3.5 ISO 3200