Planets (other than Earth) are visible to the naked eye in the night sky, and notes about their observation are consistent with all of recorded history. Some of the earliest known records are from Babylonians about 1600 BC.
why astronomers can see stars and planets at night
Because we can see the nearest planets through telescopes and for those much further away we can detect them by their effect on other planets and stars.
People commonly look through telescopes to see into space. Telescopes are used by NASA to see stars and planets very far away, and less sophisticated models are used to see planets in our solar system, or even the moon.
the roam (go around) planets. they have a camera attatced to them so that we can see what the 'robot sees. usually we send these 'robots' to space to see if there is any life on planets.
The planets orbit around the sun.
Meteors are not planets. They are pieces of ice, dust, dirt or rock that enter the Earth's atmosphere and burn up in an instant, enabling people to see them.
That's simple. They could look through a telescope and see some planets near the earth, but not all. Astronauts travel in space and study them.
People who study the sky continually over a number of nights can see the planets have moved.
when they could see
The light we see from the planets is sunlight that has been reflected.
by a telescope
See below-