The best ways to see the planetary alignment

It's shaping up to be a brilliant month for stargazing, with a blood moon and a planetary alignment.

Stardome's Josh Kirkley told Newshub how to find the planets in the vast night sky, as they won't stay in place for very long.

He said the best time to look for the alignment would be from 6:30pm to 7:30pm each night over the next two weeks, and you should look for a vantage point that gives unobstructed views of the east and west horizon.

"Mercury will be the first planet in this alignment in the west, followed by Venus, the Moon, Jupiter, Saturn, and Mars to the east. They will all form a line that stretches across the ecliptic of our solar system. Planetary alignments are quite rare because the planets are always moving.

"Planets like Mercury and Venus orbit the sun quite fast, so it's not often than that they all happen to line up at once with the other planets to have a planetary alignment. They will often only last for a week or two, or even just a few days in some cases. "

Getting away from light pollution

If you don't mind missing out on the alignment, any time after 7pm is good for stargazing, but you may need to head away from the city to escape light pollution.

Mr Kirkley said a map would be quite helpful in these cases and there is a good one available for free online. 

Finding the stars in the sky

Online is also a very good place to find maps of the sky itself, which can help you find constellations and planets.

"The best types of maps I'd recommend are smart phone apps. These allow you to see the sky in real time and can help you find precisely where particular planets and stars are," Mr Kirkley said.

"Some great apps are Sky Map, Sky Guide or Star Walk. There are many free ones on the app store if you search 'astronomy'."

Stardome makes old school star charts too for people who don't own smartphones or would prefer to take a physical copy.

How to use a star chart

Using them can be a little complex, but thankfully they come with instructions.

To match the chart with the western sky align it with the western horizon, but be aware any obstructions could cause block your view.

The Stardome website has instructions on how to use the maps and orient yourself with the sky.

"Locating the 'OVERHEAD' marker for each chart will help with orienting your view of the sky. The other key marker is labelled 'SCP' - the South Celestial Pole. The whole sky seems to rotate around this point so objects close to the SCP will never set - they are called 'circumpolar'," the website says.

"The elevation of the SCP above your horizon measures your latitude. These charts are done for the latitude of Auckland (37 degrees south). From Invercargill, the SCP will appear nearly 10 degrees  higher in the south so more of the southern sky will be circumpolar from there. The Southern Cross never sets anywhere in Aotearoa so is perpetually in our skies, even though in the very north of the country it nearly touches the southern horizon."