None. Their had only reach the moon.
Astronauts can see planets, stars, and species.
They could, but as of now, no astronauts have travelled to any other planets in the solar system.
I would suppose that the scientist with the super powered telescopes would discover planets before the astronauts would.
earth
Astronauts have landed on the Moon, which is not a planet but a natural satellite of Earth. Humans have not yet landed on any other planets in our solar system.
Astronauts have visited the Moon, which is not a planet but a natural satellite of Earth. Other than the Moon, astronauts have not visited any other planets in our solar system. Only unmanned spacecraft have been sent to explore other planets.
Well, to explore space ofcourse. Astronauts go to space to find new planets or such. They observe what is happening.
mercury
No, not yet at least. The only object that astronauts have been to other than Earth is the moon, which is a moon rather than a planet. There other planets are much farther away, but there are some plans to land people on Mars.
Yes. Astronauts do study the moon. In particular, Astronomers study the planets, stars and outer space.
They study how long to get to planets and if there is life in outer space.
Astronauts go to different planets etc and collect specimens and other things so that scientists can research and find out more about our solar system.