On 11 November 2019 the first Transit of Mercury since 2016 happened. On Earth the only two transits we can see are with Mercury and Venus. A transit occurs when a planet goes in front of the Sun. It was possible for us to see the transit using special light-filtered telescopes. It was not possible for us to see the transit without a telescope as Mercury is simply too small and we would hurt our eyes by staring at the Sun.
The transit lasted for about 5.5 hours. Mercury orbits the Sun every 88 days, but that doesn’t mean we get to see Mercury transit the Sun every 88 days. This is because Mercury’s orbit does not always line up with Earth’s orbit. The next time we will be able to see a Mercury transit is in 2032.
Mercury is the smallest planet in our Solar System. You could nearly fit three Mercury’s side by side in Earth, so even if you got the chance to look through a telescope to see Mercury chances are you couldn’t see it because it is simply too small.
Personally, I was lucky enough to see this transit happen through a special Coronado telescope that filters out sunlight here at Blackrock Castle Observatory. I got to see people from the Cork Astronomy club give presentations on the Mercury transit in action.