Earth does not need a telescope, look down.
Yes, Earth can be seen at night without a telescope. It is visible from space station and other spacecraft. However, it is not visible to the naked eye from the surface of the Earth at night.
no because its far away
Yes, but you need really clear skies to see it.
Of course, look down and you will see the Earth. Amazing, what you can do with a bit of forethought.
Yes, the planet Mars is visible to the naked eye.
Yes, but ONLY in ideal conditions, so realistically, no.
The Hubble Space Telescope has seen Earth. While its primary function is to observe celestial objects in deep space, the telescope has also been pointed towards Earth for calibration and testing purposes.
No, the Hubble Telescope stays in orbit around the Earth.
Yes. Mars has been known since ancient times, long before the telescope was invented.
The first time Uranus has been spoted by telescope by accident.
it is a comet that can been seen with a (naked eye) meaning without a telescope.
Yes, Mercury, Venus, Mars, Jupiter and Saturn had been discovered several millennia before the invention of the telescope.