On 9 May 2016 a transit of Mercury will take place, when the planet passes directly between the Earth and the Sun. Transits are rare - this is the first event of its kind since 2006, and the first seen in the UK since 2003 – and after this the next ones are in 2019 and then 2032.
If the weather is clear, then the UK should enjoy a good view of the transit. The whole event runs from 1212 BST to 1942 BST, when Mercury will appear as a slowly moving silhouetted disk against the bright solar surface. Because the planet is so small, it only blocks out about 1/25000th of the light of the Sun.
This means it is impossible to see Mercury, and dangerous to try to observe it, with the unaided eye.
Where will you watch the Mercury transit?
This is where everyone will be watching the Mercury Transit from!
Why not let us know what you'll be up to, by dropping a pin!
To allow the public to experience and observe the transit in safety, the RAS is running a special event in the courtyard of Burlington House. Experts will be on hand to operate telescopes with safe solar filters, and a projection device, to give people the chance to see the transit at first hand. In the event of cloudy weather, we will have a live feed from sites with clear skies elsewhere in the world.