Out of this world

17:00, May 24 2012
VIEWPOINT: Farm Cove astronomer Jennie McCormick with the daylight telescope she will be using to view the transit of Venus.

Jennie McCormick has her sights set firmly on the heavens.

The transit of Venus occurs on June 6 and the Farm Cove astronomer is giving the public the chance to witness the extraordinary event.

She will be setting up telescopes outside Pakuranga's Te Tuhi Centre for the Arts and letting people take a peek at the planet.

A transit occurs when a planet or other body crosses the face of the Sun. Venus will be visible as a dark spot creeping across the disc of the Sun over the course of a few hours.

"We only see the transits of Mercury and Venus or `inferior planets' which are between the Earth and the Sun so we don't see it very often," Ms McCormick says.

"Venus transits in eight-year cycles so the last one was in 2004. Before that there was one in 1882 and 1874 so fingers crossed the weather's good on the day. The next one isn't until 2117 so no-one alive today is ever going to see it again."


Past astronomers used the transit to help determine the distance from the Earth to the Sun.

"Today we know that to be about 150 million kilometres but they didn't know that in the 17th century and they had to watch the transit, take measurements and use them to calculate the distance."

This year the event is being used to analyse the planet's atmosphere by measuring the spectrum of light shining through it.

"Scientists will be looking at which gases are present in Venus' atmosphere and that will help us in the future when we're looking at extrasolar planets or planets outside our solar system."

Ms McCormick will be joined on the day by members of the Auckland Astronomical Society who will also be bringing along telescopes.

"The Sun is extremely dangerous and people mustn't look at it through dark glasses or pieces of old photographic film," she says.

"The telescopes we're going to use are solar viewers and are safe for looking at the Sun. It's so great to see the solar system in motion like this.

"If you can't come along on the day contact your local astronomical society and purchase solar viewers. Don't just go outside and try to look at it. Solar viewers aren't expensive and they're a safe way to view the transit."

Eastern Courier