Stargazers hoping to catch a glimpse of comet ‘Lovejoy’ this weekend should ditch the cigarettes, an astronomer has advised.
The glowing green comet is making its closest approach to Earth at the moment, proving amateur astronomers a sight that will not be seen again for 8,000 years.
And while it may be tempting to indulge in a cigarette while shivering in the January chill, astronomer Geoff Wyatt said it could prevent people seeing the comet.
Mr Wyatt said smoking affects the blood supply to the optic nerve and reduces night vision.
He also advised getting away from light pollution to improve the view.
“There's a lot of beautiful stuff up there in the night sky," said the Sydney Observatory astronomer.
"We all know the hit-parade things – the moon, the stars and the planets. But every now and then you get something out of left field and it's like a surprise birthday present.
"Getting away from light pollution would improve the view, as would not smoking a cigarette immediately beforehand."
This weekend Lovejoy is just about bright enough to be glimpsed as a small smudge of light with the naked eye.
Through a small telescope or binoculars it appears as a softly glowing, bluish green ball., roughly half the apparent width of the moon.
The comet is currently in front of the constellation Taurus the Bull by January 9 having just passed by Orion, one of the easiest constellations to find because of its three star ‘belt.’
The comet is currently near Taurus to the right of Orion on the far left
Like other comets, Lovejoy is big chunk of ice and dust orbiting the sun. It belongs to the family of "long period" comets which means it takes a long time to travel in from the fringes of the solar system.
The object last passed through the inner solar system 11,500 years ago, and is not expected to return for another 8,000.
On Wednesday the comet reached its closest point to the Earth, a distance of 44 million miles, but it will remain easy to spot for about the next two weeks.
Robin Scagell, vice president of the Society for Popular Astronomy, said: "It appears bluish green and is quite pretty, but not dramatic. I would call it a good workmanlike comet.
"The nice thing about it is that its visible at night rather than at dawn or dusk."
The comet was discovered on August 17 last year by Australian amateur astronomer Terry Lovejoy, who spotted it in images taken by his eight-inch backyard telescope.