Weather could stand in way of lunar eclipse

This digitally enhanced photo shows the progress of the lunar eclipse, from partial eclipse at top left to luna rosa in the main image. Photo/file

Tauranga Astronomical Society president Stuart Murray said the weather would be a deciding factor as to whether or not Tauranga residents will be able to see tomorrow's lunar eclipse.

Murray said the moon could appear brighter and bigger than usual as it moved its closest to Earth and was expected to be at its total eclipse from about 2am.

"That period of time occurs very irregularly," Murray said. "The coppery-colour is dependant on the sunlight coming through the Earth's atmosphere."

But Murray said it could be a disappointment to many keen astronomers because of possible broken cloud and rain hiding the lunar eclipse from view.

Murray said if people were interested in seeing the lunar eclipse their best chance at spotting the big, bright moon would be between 2am and 4am tomorrow if there was a break in the cloud.

"All they need to do is peer out their window and look to the north. But if it is raining, stay in bed," he joked.

Murray said the blood moon effect comes from the sunlight streaming from the northern atmosphere giving the moon a red colouring.

He said a blue moon only occurred when there was a full moon on any month like tonight.

"If the cloud clears just before midnight we will see a full moon and very slowly for about one-and-a-half to two hours after that the Earth's shadow will move across the face of the moon," he said.

"Just before 2am all of that reflective light from the moon's surface will have disappeared. At that stage, or just before, we will start to see that colouration."

How red the moon will be and how easy it will be to see will depend on the weather and how much sunlight is scattered through the clouds, Murray said.

He said the Matua observatory on Tilby Dr would not be open for people to view the eclipse, but he did not expect many people to be waking up that early in the morning particularly if the weather is bad.

MetService meteorologist Tui McInnes said moon rise was predicted at 8.10pm and would set at 5.30am tomorrow.

McInnes said thick cloud was expected to block the view of tomorrow morning's lunar eclipse.

"The cloud looks like it will break away during the day but it is set to return tonight which could hamper viewing opportunities for the supermoon," he said.

"It is going to be quite solid, but the only silver lining is any breaks in the cloud will start to make things more visible, and the moon is very bright at the moment."