Space Events

Mercury to make rare transit across the sun

Astronomers both amateur and professional alike are in for a treat on Monday as Mercury makes a rare transit of the sun. The solar system's smallest, innermost planet will resemble a black dot as it passes in front of our big, bright star on 9 May.

The last time Mercury crossed directly between the Earth and sun was in 2006, and it won't happen again until 2019 - and then, until 2032. There will be a large window of opportunity to see it – Mercury will take seven and a half hours to cross the solar disc.

Moving westwards, observers in China, India, the Middle East, most of Africa and Eastern Europe will be able to watch the majority of the transit, but the sun will set before Mercury leaves the sun's disc. The further west your location is, the more of the 7.5-hour event you'll have access to.