Moon lighting: Partial lunar eclipse longest since 1440

LOS ANGELES • The longest partial lunar eclipse in nearly 600 years, which bathed the Moon in red, was visible for a big slice of humanity yesterday. The celestial show saw the lunar disc almost completely cast in shadow as it moved behind the Earth, turning 99 per cent of its face red.

The spectacle was visible across all of North America and parts of South America from 1.02am Eastern Standard Time (2.02pm Singapore time) and may later be seen in Polynesia, Australia and north-east Asia. Around two hours later, sky-watchers with a cloud-free view in those regions saw the Moon half covered by the Earth's penumbra - the outer shadow.

Space scientists had said that by 3.45am Eastern Standard Time, the Moon would appear red, with the most vivid colouring visible at peak eclipse 18 minutes later.

The dramatic red is caused by a phenomenon known as Rayleigh scattering, where the shorter blue lightwaves from the Sun are dispersed by particles in the Earth's atmosphere. Red lightwaves, which are longer, pass easily through these particles. "The more dust or clouds in Earth's atmosphere during the eclipse, the redder the Moon will appear," the US National Aeronautics and Space Administration (Nasa) explained. "It's as if all the world's sunrises and sunsets are projected onto the Moon."

From the moment the eclipse began - when the Moon entered the Earth's shadow - to when it ended took over three hours and 28 minutes. It is the longest partial eclipse since 1440 - around the time German inventor Johannes Gutenberg invented his printing press - and would not be beaten until the far-off future of 2669. But Moonwatchers would not have to wait that long for another show - there will be a longer total lunar eclipse on Nov 8 next year, Nasa said.