A partial moon eclipse and comet share double billing over the weekend.
The moon will pass into Earth's outer shadow, or penumbra on Friday night casting a light shadow, while Comet 45P will zoom past Earth early on Saturday morning.
It will be an extremely close encounter as these things go, passing within 12.4 million kilometres of Earth. Its relative speed: 22.9 km per second, or a breakneck 82,270 km/h.
The ice ball - an estimated 1.5km across - comes around every five years.
It will appear glowing green in the constellation Hercules.
Stargazers have been tracking Comet 45P for the past couple of months. It's officially known as Comet 45P/Honda-Mrkos-Pajdusakova, named after the Japanese, Czech and Slovak astronomers who discovered it in 1948.
The eclipse will last more than four hours with the action unfolding early on Saturday in Europe, Africa and western Asia.
It won't be visible from Australia because of the time zone but the comet can be glimpsed in the very early morning on Saturday with the help of a dark sky and binoculars.
