News in Science

Bad weather may rain on unusual Easter eclipse

Easter eclipse Easter is just around the corner - and so is the only total lunar eclipse for the year that can be seen right across Australia, if rain doesn't spoil the parade.

Skywatchers will be treated to a red-tinged moon this Easter Saturday night -- if they live in an area that's not blanketed by cloud.

Even then they'll have to be quick -- or lucky -- if they want to catch the moon in full totality.

This eclipse will be the shortest in at least a century -- if not longer, says Andrew Smith an astronomer at Sydney Observatory.

"There are a couple of different ways of measuring eclipses. Some sources indicate it will be around 10 minutes of totality, which will make it the shortest since 1917, but other sources say it will be less than five minutes, which makes it the shortest since 1592," says Smith.

Total lunar eclipses occur when the Earth passes between the Sun and the Moon casting a shadow on the face of the Moon.

This one will be super-short because the moon is just scooting the inside edge of the Earth's shadow, says Smith.

"Imagine one small circle crossing in front of a larger circle -- instead of going across the middle, which would take the longest, it's just going across the inside edge. That's the shortest distance it can travel through that shadow," he explains.

And, as it's not going deep into the Earth's shadow, it may not appear deep red during totality but take on a two-tone effect.

"What's most likely is the side of the moon that's furthest into the shadow will be a deeper red and the edge of the moon that's only just in the shadow might be a brownish-grey."

Its appearance will also be affected by factors such as pollution and dust in the air.

"What creates that reddish light is all the light from all the sunsets and sunrises on earth, that's the only light that reaches the Moon during a total eclipse," says Smith.

Eclipse times

The moon will appear in the north-east sky right across Australia -- higher in the sky in the eastern states.

Weather forecast

The only thing to get in the way of a good eclipse is the weather, and unfortunately the forecast for Easter Saturday does not bode well for many parts of Australia, says Simon Allen, senior meteorologist from the Bureau of Meteorology.

"Of the capital cities it looks like Adelaide is the best bet. The forecast there is for clear skies," says Allen.

Perth and Darwin may have a chance of seeing the eclipse depending on the location of cloud bands and storms to the north, although a large part of WA will be cloudy.

But Allen says the weather "doesn't look good for the eastern seaboard of Australia."

While Hobart, Melbourne and Cairns are likely to have patchy cloud, Allen says Sydney and Brisbane will have significant rain.

"Sydney and Brisbane are the least likely to see it."

This lunar eclipse is the third in a series of four lunar eclipses in a two-year-period. However, the next eclipse on 28 September will not be visible in Australia as it happens during the day.

Australians will have to wait until 31 January 2018 to see the next total lunar eclipse.

Related: 2015 Aussie Sky Guide