The light of the sun is too bright to make out the planets during the day unless there is an eclipse.
because the sun is so bright that it covers it up!! jk idk
because at night they cant see =]
because soem planets are to far away and our eyes cant see that far
when its enemies attack during the day, they can see him...but at night they cant see him.
During the day, the light of the Sun is so intense and so scattered by the atmosphere that the light of the stars is unnoticeable.
The reason you can see planets and stars at night is that their light is faint and the brightness of the sun obscures them during the day. At night, when the sun is not visible, the fainter light from the planets and stars can more readily be seen.
Because the sun is brighter than stars
Well you can see the moon during the day time maybe its because the objects (planets or stars) are ages away. Also since its bright in the day time that also could affect being able to see or not to see the objects.
The stars are not visible during the day because bight sunlight scattered by the atmosphere masks the relatively dim light of the stars.
Antarctica can see the planets so well as there is no smoke or gas polluting the air s you can see into space were as in other places in the world you cant see through the smoke and gas in the air!
Stars in general disappear in the daytime because the bright diffused light from the Sun overpowers the dim starlight.
He knew about 6 planets. See the related link for further information.