Mercury in the sky – level 3
This may just look like another sun spot or solar flare but it is, in fact, something much more rare. This dark circle, moving across the sun, is the planet Mercury.
The planet passes directly between Earth and the sun about 13 times every century. The last time this happened was 10 years ago in 2006 and the next time will be on November 11th ,2019.
So who could see this rare phenomenon? This year's transit was visible for most of the earth, including the Americas, Europe, Africa and much of Asia. And this isn't a "blink or you'll miss it" phenomenon, the transition lasted 7 hours.
Experts warned those looking for the planet to be careful. Mercury's black disc only covered a tiny proportion of the sun and looking at the sun with unprotected eyes can be very dangerous. But those with the right equipment enjoyed this rare event, and those who didn't will have to wait at least another three years.
Difficult words: solar flare (a brief eruption of intense high-energy radiation), phenomenon (something which happens in nature), disc (a thin circle).