Transit of Mercury schools challenge

The European Space Agency (ESA) are inviting European schools to join together to observe the transit of Mercury taking place on Monday 9 May 2016. Schools are challenged to observe the transit and to recreate the measurements made by astronomers around 300 years ago in order to calculate the distance between the Earth and the Sun.

A transit occurs when a one celestial object passes in front of another. From our viewpoint on Earth, it can only be the two innermost planets in the Solar System, Mercury and Venus that transit the disc of the Sun.

A transit of Mercury is a relatively rare event happening only 13 or 14 times each century. Mercury actually passes between the Earth and Sun at least three times a year, however since its orbit is inclined with respect to the plane of the Solar System, it usually appears to pass above or below the Sun to an observer on Earth. During a transit, Mercury appears as a small black dot moving across the disc of the Sun.

Find out if you can enjoy this event from your location, here

ESA invites schools to observe the transit of Mercury and to measure the times that the edge of the disc of Mercury makes contact with the edge of the disc of the Sun. Once you have calculated your measurements, you can submit a short report of your transit experience to be published on the ESA website, and be in with a chance of winning a prize.

Visit the ESA website for more information or contact


Who can participate?
The transit of Mercury challenge is recommended for schools and groups of young people in secondary level education.

If you are observing the event please remember to NEVER look at the Sun with unprotected eyes, through ordinary sunglasses or through a telescope, as this might cause permanent damage to your eyes.

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