Question

Support an argument that the gravitational force exerted by Earth on objects is directed down.

Answer 1

Astronauts have safety tethers which are the same thing as cords/ropes which prevents them from floating away from the moon.

Answer 2

If you jump up and down on Earth, what happens? You go right back down. If the gravitational force wasn't going down, we wouldn't even be able to stand on Earth without floating away.