Tonight's the night: Mars Watch reminds us that at 5:51 a.m. (ET) tomorrow, Mars will be a mere 55,760 thousand kilometers from here (as the space crow flies) -- and the last time it grazed so close overhead (59,619 years ago) there were still Neanderthals living openly among us ...

So how do you find Mars?

At the appointed time, look roughly south west -- ok, really, at nearly half an arc-minute across and the brightest thing next to the moon (which is soon to be New so you can't see it anyway), and directly opposite the Sun (the red circles in the starchart here are the Earth's shadow) it's pretty darn hard to miss on any night in 2003.

For those of you up near our neck of the woods, on this particular night of Mars viewing, you might want to do your gazing a little earlier: the horizon (the white line) is pretty close to the planetary angle come close-approach time. From 10pm onward any night this week, search the south-east and check out anything bright and reddish.

How close is it?

It's about half the apparent size of Jupiter, so those of you with smaller scopes and binoculars will already know that this means pretty much a dot, but a fat dot -- one website described it as an orange seen across a tennis-court: You can tell that it's an orange, but you can't say much else about it -- if you really want a view, your very best bet is to seek out a star-party or contact your local observatory and ask about viewing schedules (astronomers love company ... in moderation) Naturally the Hubble and many other large scopes will be pressed into service (assuming there are clear skies on Mars too) and you can expect your morning news to have a few shots to spice up their science pages marking the event.

So what does it mean to have Mars so close? To some, it means nothing at all beyond an unusual lightshow, to others it's a foreboding omen, a herald of destruction by fire, iron knives (don't run with scissors!) and angry armed militias. James Wilson (1880) says of Mars in his Dictionary of Astrology:

choloric, feminine, nocturnal, malignant, violent planet, and is called the lesser infortune ... I deem him more injurious than Saturn. ... when in perigee, he appears like a flame, or bright spark ... at this time the weather is warmer than is usual for the season, but this may arise from other causes ... It is certain, however, that murders are more frequent and of a more atrocious nature, at the time when that planet is nearest the Earth ... (p315)

Hone (1951) says only that it is a time prone to "overstrain through overdoing, thus impairing the virility" so you can take that how ever you wish.

Mystic musings and proffered prognostications aside, for those curious to know how we just happen to know the exact time and angle of this event, Dr Michael McCabe, Principal Lecturer in the Department of Mathematics at the University of Portsmouth, has assembled a brief tutorial

Read it carefully. There will be an exam later.

If the Martians don't come up broadside and board us that is.