Dull and duller... Earth is becoming a little less bright

VIEWED from space, the ‘pale blue dot’ we know as Earth has become less bright, experts say.

Our planet has dimmed in the past three years, scientists have discovered. Researchers have been steadily tracking the brightness of Earth, from its reflection on the Moon.

It has dimmed by the equivalent of half a watt less light per square metre, making it around 0.5% less ‘shiny’ in the past three years.

It is not a difference anyone walking around on Earth could notice, or even an astronaut viewing it from space, unless they had a specialist telescope.

But the reduction in ‘earthshine’, also known as albedo, is caused by a recent loss of clouds which reflect back half of the Sun’s rays.

And if less sunshine is bouncing back off the clouds, so that the planet glows less brightly, it also means more sunshine is staying on Earth, which could contribute to global warming.

Professor Philip Goode, lead author of a study on the dimmer Earth, from the New Jersey Institute of Technology, said: ‘This was not what we expected at all, as for 17 years there has been scarcely any change in the Earth’s brightness. It was very hard to get motivated to analyse the last three years of data for that reason, but we promised to do 20 years, and so we did. Then, son of a gun, it was dimmer than we had seen before.’

He added: ‘This will reverse, as it has in the past, but we are curious and apprehensive about this, because the next time it happens, the Earth could potentially be even dimmer and let more sunshine in.’