"Gravity"

If we make the space station in space into a ring and let it rotate, then the humans in it will also feel the "centrifugal force" to "push" themselves towards the outer wall of the space station

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

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

In the photos returned from the rover, we see Mars as a desolate world without a trace of life. Although Mars looks desolate and dry, there are many people who believe that Mars may become a second home for us humans