How to view the 9th May Mercury Transit

Mercury Transit MAP

A graphic showing where the 9th May Mercury transit will be viewable. Note: the times shown in this video are in Easter. Daylight Savings Time. Credit:


This event, known as a transit, will be visible from most of western Europe, including the UK and Ireland, as well as South America and the eastern parts of North America.

Transits of Mercury are rare, with only 13 or 14 occurring each century.

After Monday’s transit the next one will not be until 11 November 2019.
ESA will be live streaming the event, but the transit can be observed using a dedicated solar telescope or properly filtered astronomical telescope.

Credit: NASA

Mercury will appear 1/150th the size of the Sun’s diameter as it crosses the disc and will be too small to spot with the naked eye.

For this reason, eclipse glasses and other kinds of eye protection for looking at the Sun will be unsuitable.

Viewing the Sun with the naked eye or an unfiltered regular telescope is incredibly dangerous and could cause permanent blindness.

More information about observing the transit safely is available in this Open University video.

If you happen to reside in or around Bristol, BBC Sky at Night Magazine has joined with the At-Bristol Science Centre and Bristol Astronomical Society to host a free event in the city’s Millennium Square from midday.


We will have expert astronomers on hand to provide information, as well as solar telescopes to observe the transit, and At-Bristol will be projecting the event on the square’s Big Screen.