Close encounter with the red planet

Mars should already appear brighter than normal to star-gazers and good telescopes should be able to make out some of its features. Photo / Getty Images

Star-gazers are enjoying their best view of Mars in a decade.

It comes as Mars approaches "opposition" next month - when the Earth will be sitting directly between Mars and the Sun at just 75.3 million kilometres away.

Those with good telescopes can already expect to see Mars' red colour mottled with dark and the white south polar cap.

Otherwise, people will notice Mars is much brighter than normal, even rivalling Jupiter, and it will move distinctly against the background stars from night to night.

The phenomenon occurs because Earth orbits the Sun at a speed one-quarter faster than Mars, meaning Earth "catches up" with and overtakes the red planet every 26 months. This not only puts Earth on the same side of the Sun, but brings Mars and Earth closer together.

As Earth passes Mars relatively quickly, the best time for telescope viewing is just a few weeks before and after the opposition.

Over this time, Mars will be rising as the Sun sets and will be high in the sky around midnight - perhaps the best time to view it with a telescope.

Stardome astronomer Dr Grant Christie said he had a great view through the Auckland observatory's telescope at 4am yesterday.

"It was a marvellous sight, the best I've ever seen. If you are just looking at it with the naked eye, you can watch it each night and you'll notice it slowly moving relative to Saturn and Antares as it's approaching opposition."

Although the official date of opposition is May 22, the closest actual approach will be on May 31.Jamie Morton

A date with Mars

• The Earth will come within 75.3 million km of Mars when the red planet becomes "at opposition" next month.

• This will prove the best chance in a decade to view the red planet, but it's set to come even closer in July 2018, at a distance of just 57.6 million km.

• Mars should already appear brighter than normal to star-gazers and good telescopes should be able to make out some of its features.