It takes place when Mercury passes directly between the sun and a superior planet, becoming visible against (and hence obscuring a small portion of) the solar disk. During transit, Mercury appears as a tiny black dot moving across the disk of the sun. When Mercury transits the sun, you can see it as a tiny black dot silhouetted against the sun's disk.
After the transit, the next will be in November 2032. A typical transit lasts several hours.
Since Mercury is only 1/194 of the sun's apparent diameter, a telescope with a magnification of 50x or more is recommended to watch this celestial event. The telescope must be suitably equipped with adequate filtration to ensure safe solar viewing.
The group's CEO Hasan Al Hariri said people should be careful while observing it. "Extreme caution should be taken to ensure that no one looks at sun through the eyepiece without filters. Even touching the eyepiece can be painful, as it will rapidly become extremely hot. Also take care not to pass your hand close to the eyepiece, such that the sun's light is focused onto it. This can cause painful burns in an instant."
> Don't ever look at the sun without proper eye protection
> Don't view the sun through sunglasses of any type (single or multiple pairs), or filters made from photographic film, or any combination of photographic filters, crossed polarisers or gelatin filters, CDs, CD-ROMs, or smoked glass. None of these are safe.
> Don't fit any filter to a telescope without first checking it thoroughly for damage. If it is scuffed, scratched, has pinholes in it, or you have any other doubts about it at all, don't use it
> View sun only through special filters made for safe solar viewing. Ensure they are designed to be fitted securely to the kind of instrument you have.Watch the transit live online: