When it comes to orbital motion, Mercury fairly nips around the Sun. A year on Mercury takes a mere 88 Earth days. It used to be thought that Mercury’s axial spin was equal to the orbital period — in other words that the same side of the planet always faced the Sun, as with the Moon relative to the Earth. Now we know that for every two Mercurial years, there are three Mercurial days.

Three times in an Earth year Mercury appears to move backwards along its orbit. This is an optical illusion, of course, caused by our fixed perspective from the Earth’s own orbit. Astrologers know that retrograde Mercurial periods can be times of mis-communication here on Earth. There can be lost letters, un-returned emails, dust-ups with loved ones, funny business while traveling, and other Mercurial mischief … positive uses of these times can include, but are not limited to, checking the details, catching up on the filing, editing the manuscript and re-scheduling the extreme sports holiday.

There’s astronomical data on Mercury and other celestial bodies here. And you can get the astrological perspective here, at Astro — If you scroll down when you get there, you’ll see that at the time of writing, Mercury is in Pisces (but not for long). A good time to broach sensitive subjects possibly?

Called Mercury by the Romans, Hermes by the Greeks, the trickster God appears in Shakespeare as Ariel in The Tempest, and as Puck in A Midsummer Night’s Dream. And I guess The Donkey in Shrek would have a prominent Mercury in his chart.