Skywatchers in Cornwall have been observing Mercury transit the Sun

Skywatchers in Cornwall joined hundreds of others across the region trying to observe a rare celestial event, Mercury transiting the Sun.

Mercury's sojourn between Earth and the Sun took several hours and is in its last stages tonight.

Those at the Roseland observatory near St.Austell set up their equipment but were let down by the cloudy weather. Mercury won't make another transit until 2019...and then 2032.

The event is impossible - and dangerous - to view with the naked eye or binoculars, but astronomy groups worldwide are offering the chance view it through filtered telescopes.

Live views from space are also available online.

They show the little planet's third such pass of 14 it will make this century. Mercury as a tiny black circle, smaller but darker than many sunspots, slowly traversing the Sun's giant yellow disc.