IF YOU are out and about around midnight on New Year's Eve, and can still focus your eyes, take a look to the south before Big Ben's bells announce the start of 2013. There, above the treetops, you'll see Sirius, the brightest star in the whole sky, glittering like an icy diamond.

Because Sirius never climbs very high in the sky as seen from the UK, we always see it through lots of distorted air above the horizon. That's why it appears to flash and sparkle with countless shades of blue, red and green on these frosty winter nights.

Sirius is one of the closest stars to us, only 8.6 light years away. That means when you look at it the light entering your eye set off almost nine years ago. Time travel, and you don't even need a Tardis!

Stuart Atkinson

Eddington Astronomical Society of Kendal