A rare event brought the world of astronomy to a halt on Monday, November 11th. This had nothing to do with the commemorations of the signing of the armistice: everyone was looking up at the sky. And for good reason, an extraordinary spectacle occurred, that of Mercury's 'transit' in front of the Sun.Thus, the most fortunate had the chance to see the smallest planet in the Solar System passing in front of our star. And these people were not very numerous in the UK, given the unfavourable weather conditions on Monday, November 11th. This is a pity because this alignment of the planets only occurs thirteen or fourteen times a century and will only be observed again in 2032.A magical showThis footage actually summarises a seven-hour 'transit' as seen from Earth. The last time this show took place was in May 2016 and again, unfortunately, the weather conditions were not very good for British observers. But then again, NASA had used its best satellite telescope to record the event.In the video above, recorded and posted by NASA, we can clearly see the small planet passing in front of the Sun, whose immensity is evident. Almost three times smaller and twenty times less massive than the Earth, Mercury stands out among the telluric planets. It looks like a very small dot, which passes in front of the Sun... and which is, in reality, a whole world. Pretty magical.