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By Hamish Johnston
The transit of Mercury across the face of the Sun has begun. Alas here in Bristol the skies are grey and I have been watching a live feed of the transit from the Royal Observatory in Greenwich – which has been blessed with clear skies. That’s a real shame, because I had brought a small telescope into work and I was looking forward to projecting a magnified image of the Sun onto a screen to see the transit for myself.
If you would like to view the transit please don’t look directly at the Sun (and never look at the Sun through a telescope or binoculars). Also, don’t bother with eclipse glasses or welding goggles – Mercury is too small to be seen with the unaided eye.
We have put together a few tips about how you can safely view the transit along with some fascinating facts about Mercury. Did you know, for example, that a “day” on Mercury lasts more than twice as long as a Mercury “year”?
If the skies are clear where you are, there is no need to rush outside because the transit will continue until about 18:42 GMT today.
Update at 13:57 GMT: It seems to be cloudy over Greenwich at the moment. Here is another live stream of the transit taken under clearer skies.
In the write up: “Did you know, for example, that a “day” on Mercury lasts more than twice as long as a Mercury “year””? What a mercurially shrouded remark! In fact, as in the video: One day-night cycle on the Mercury lasts about half the year on the Earth!