Tens of thousands of people have travelled across the world for the chance to watch a total eclipse.

It will be visible initially in northern Australia, then towards the east as far as the tiny Juan Fernandez Islands off the west coast of Chile.

Many of the scientists, tourists and amateur astronomers have flocked to Cairns, which is the largest city which will experience totality.

Cairns will have two minutes of darkness just one hour after sunrise, at 20:39 GMT on November 13 (06:39 on November 14 local time). When the eclipse occurs, the sun will be quite low in the sky, at an altitude of just 14 degrees.

It’s estimated that 50,000 people have descended on northern Australia to watch the spectacle, and some hotels in Queensland have been booked up for more than three years.

A solar eclipse is caused by the moon passing between the sun and the earth, blocking out the image of the sun.

The moon travels around the earth in an elliptical path, and a total eclipse can only occur when the moon is closer to the earth, and therefore appears to be as large as the sun. At this point all sunlight would be obscured.

Totality occurs in a narrow path across the surface of the Earth, but a partial solar eclipse is visible over a region thousands of kilometres wide.

During the eclipse of November 2012, Northern Australia is the only part of the world where there’s the chance of seeing totality. However, a partial eclipse will be visible in Eastern Indonesia, Papua New Guinea, Eastern Australia, Northern New Zealand and the southern parts of Chile.

The bad news for enthusiasts is that the weather in Cairns is not expected to be play ball. Rain and cloudy skies are forecast, and although there are expected to be a few breaks in the cloud, a sight of the eclipse will be hit and miss.

If the skies do prove to be cloudy, the enthusiasts will have to wait until 20 March 2015 for the next total eclipse, which will be seen in the Faroe Islands.