A noted German astronomer has been celebrated with his very own Google doodle. Head to the Google home page, and you'll see the bearded academic -- complete with his own natty ruff -- being orbited by a small blue planet.
Johannes Kepler was born in Weil der Stadt near Stuttgart in Germany. He is best known for his first law of planetary motion, which states that planets travel in an ellipse to orbit the Sun.
He worked as a maths teacher in Graz, Austria, then became an assistant to astronomer Tycho Brahe. He later became the imperial mathematician to Emperor Rudolf II.
Kepler incorporated religious reasoning into his work. He was motivated by his faith, and believed that he was close to discovering God's geometrical plan for the universe.
It was while studying Mars that he realised that all planets move in an elliptical orbit. He published his findings in the publication Astronomia Nova between 1609 and 1619.
Kepler died aged 58 on 15 November 1630.
Google doodles celebrate big occasions, or the anniversaries of noted figures in a certain field, be it science, maths, the arts, or entertainment. Past subjects of a Google doodle include, , , , and . Google has also celebrated events like , , and with their own doodles.
The practice started back in 1998, when the then relatively little-used search engine's engineers decamped to Burning Man Festival for a jolly. Google put a little man on the home page to let everyone know they weren't there, so if there was a problem with the servers, they couldn't fix it.
Which is your favourite doodle of all time? And has Google missed any golden opportunities for one? Let me know in the comments, or on our Facebook page.