The transit of Venus - a quick guide
ABOVE: Explanatory video courtesy NASA.
Transits of Venus come in pairs, once every eight years.
Today's transit (10.15am to 4.43pm June 6 NZ time) will be the last chance to see Venus traversing the face of the Sun until 2117.
Astronomers warn not to look directly at the transit.
Are regular sunglasses okay for staring at the Sun as Venus crosses its face?
"Only for about a second," a Stardome rep told NBR ONLINE. Most sunnies don't block out all harmful UV rays.
In any event, even the most ignorant segments of the population should be spared Day of the Triffids-style blinding en masse. Forecasters expect thick cloud to cover most of the country tomorrow.
If the skies do happen to clear, and you're stuck without solar glasses, Stardome suggests taking a photo with your digital camera then looking at the transit onscreen.
"Or try looking at a reflection in a bucket. That's what we used to do," said the Stardome rep.
Nasa is running a live webcast of the transit here.