Early risers on Tuesday will get to see the very end of an astronomical phenomenon that only happens about once a decade - the transit of Mercury.
The smallest planet of the solar system will cross in front of the sun at 1:34am, when the star is still beneath the horizon.
But when it rises at 6:07am Mercury will still be in front of sun, and will appear as a small black dot.
"Since the Sun is near the horizon at this time, we recommend going to a high point or finding an unobstructed area with free sight to east-southeast for the best view of the transit," says timeanddate.com.
Just under an hour later, Mercury - the closest planet to the sun - will leave the sun's edge and disappear from view, no longer blocking the sun's rays and not emitting any light of its own.
The transit happens about 13 or 14 times a century. Though Mercury orbits the sun every 88 days, the reason we don't see a transit four times a year is because its orbit doesn't quite line up with Earth's. It usually passes just beneath or above the sun, completely invisible to the naked eye.
Measuring the effects of Mercury's transits on the sun's light has been crucial to finding planets elsewhere in the galaxy, which are normally detected when they pass in front of their star and dim its light.
The next transit of Mercury will take place in November 2032, and will again only be briefly visible in New Zealand.
Venus' last transit was in 2012, but the next one won't be until 2117. The other planets don't transit because they're all further from the sun than Earth - it would be incredibly worrying if Jupiter was between us and the sun.
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Astronomers recommend taking safety precautions when trying to view the sun directly through binoculars and telescopes - its rays are powerful enough to crack and melt substandard filters, not to mention harm your eyes.
There are a number of livestreams online, and space.com has a guide on how to build your own projection system to watch it without worry.
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Some stargazers will be gathering at Te Whanganui o Hei/Mercury Bay in Coromandel, which got its English name after the phenomenon was witnessed by astronomer Charles Green and Captain Cook in 1769.
In the South Island, astronomers will be gathering at Takaka Hill, Tasman, to promote the region's planned Wai-iti Dark Sky park.
But it will all be for naught if something a bit closer than Mercury gets in between us and the sun - clouds. It likely won't be raining in Takaka, but there might be a few clouds around to spoil the show. Whitianga, near Mercury Bay, has a similar forecast, as does Auckland.
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