Greg Power, student
I'm not sure the most popular activities but I know that there are lots of people who really like astronomy. There are groups with telescopes, star maps, and so on. I find it very interesting. Of course, events like Shoemaker Levy-9 falling on Jupiter https://solarstory.net/comets/shoemaker-levy-9 are very seldom but still observing stars, Moon, planets is cool.