Mercury Transit 2006

For the first time since May 2003, the planet Mercury made a transit across the face of the Sun, when viewed from the Earth. Although Mercury orbits between the Sun and Earth several times a year, it is pretty rare that it will transit directly in front - most of the time it is just above or below the solar disk.

Time-series of images showing Mercury transit.
© SOHO/ESA

Because the transit occured between 8.10 pm (8th Nov) and 1.10 am (9th Nov), i.e. our nighttime, it was only visible from the Americas, Pacific Ocean, eastern Asia and Australasia. Here we have cobbled together a time-series of images from the SOHO space telescope, which observes from a point between the Earth and Sun. Mercury is the tiny dot moving from left to right.

The transit or passage of a planet across the face of the Sun is only possible for the planets Mercury and Venus, because they both orbit closer to the Sun than Earth; i.e. they are the only ones that can get in the way. There are approximately 13 transits of Mercury each century and the next one won't happen until May 2016.