Lunar eclipse

I hope to stay awake tonight for the lunar eclipse, due at 11.16pm and lasting 51 minutes.

The total lunar eclipse on December 10, 2011 will be visible in its entirety from all of Australia, New Zealand and Asia.

According to this amateur astronomy website, a lunar eclipse occurs when part or all of the Moon passes into Earth’s shadow. This doesn’t happen every full moon though, because the Moon’s orbit is actually tipped about five degrees with respect to Earth’s orbit around the Sun.

This means that during most full moons, the Moon is actually above or below the Earth’s plane and therefore not in the shadow of the Earth.

With a total lunar eclipse, the moon can take on a range of striking colours.

Scattered sunlight passes deep through the Earth’s atmopshere which filters out most of the blue light. The remaining light renders the Moon in shades of red, orange, yellow and brown, depending on the amount of dust and volcanic ash in the Earth’s atmosphere.

According to Wikipedia, this eclipse is one of four in a short-lived series.

The lunar year series repeats after 12 lunations or 354 days (shifting back about 10 days in sequential years).

Because of the date shift, the Earth’s shadow will be about 11 degrees west in sequential events.

Adelaide is forecast to have cloudy weather for the rest of today, with some sunny breaks in the afternoon.

Hopefully the sky will be clear for this infrequent astronomical event.

The next total lunar eclipse visible to Australia won’t occur until April 15, 2014.