An artificial satellite orbiting around the Earth does not fall down. This is so because the attraction of Earth

1. An artificial satellite orbiting the Earth is constantly under the influence of Earth's gravitational attraction. 2. This gravitational force acts as a centripetal force, continuously pulling the satellite towards the Earth's center. 3. According to Newton's laws of motion, a force causes acceleration (F=ma). Therefore, the Earth's gravitational attraction provides the necessary centripetal acceleration. 4. This acceleration constantly changes the direction of the satellite's velocity (its speed might be constant in a circular orbit, but its velocity vector is always changing), keeping it in a curved path (orbit) around the Earth instead of flying off in a straight line or falling directly down. Option (D) correctly identifies this role of Earth's attraction. 5. Option (A) is incorrect as gravity extends far into space. Option (B) is incorrect as the moon's effect is much smaller than Earth's at satellite altitudes. Option (C) is related but less precise; the acceleration (due to gravity) is the fundamental cause required for the orbital motion, maintaining the necessary velocity.