If a shot is fired at the moon from the space station, the bullet fired will be firmly bound by the earth's gravity and it will be impossible to hit the moon

Whichever way you look at it, humans cannot be the only intelligent creatures in the universe. As far as we know, the universe has existed for at least tens of billions of years, so a reasonable speculation is that there is probably an advanced civilization in the universe that is hundreds of millions or even billions of years ahead of humans, and if that is the case, their level of technology is something that we humans simply cannot imagine.

Below the solar system, there is a star system labeled "alpha Centauri".

The Big Dipper is located in the constellation Ursa Major, and under good observing conditions, we can find them almost every day in the night sky of the Northern Hemisphere. These seven shining stars form a unique spoon shape that is very easy to recognize.

Compared to radio messages sent by humans, this method seems to be more suitable for intelligent civilizations to announce their presence in the universe, because this method belongs to the "broadcast" in space, and intelligent civilizations in all directions can be observed