Scientists (astronomers) can and have seen planets going round stars other than our own Sun.
See related link below.
They are in all three. Planets are in solar systems. There are lots of solar systems in a galaxy. There are lots of galaxies in the universe. So any planet is in a solar system, a galaxy and the universe.
Those are both poorly worded versions of the same question. The question should read:"Does the universe have nine planets?"And the answer is:"No. The Universe has trillions and trillions of planets, but our solar system has eight planets."
Scientists
Discovering more planets helps scientists to better understand the diversity of planetary systems in the universe. This can provide valuable insights into the formation and evolution of planets, as well as clues about the potential for extraterrestrial life. Additionally, expanding our knowledge of planets outside our solar system can inform our understanding of Earth's place in the cosmos.
Planets are in the solar system comprising the universe. Mammals live ON a planet, like on this planet Earth.
to make sure that every one know there are more planets
Currently there are 353 known extrasolar planets (that is to say, outside of our solar system), but it is unknown how many planets exist in the universe.
no because if there was a parallel earth there would have to be parallel planets
It just goes all around the Universe/Space.
gravitational pull..also for all we know is that the universe goes on for ever maybe you meam the solar system?
Studying the earth helps scientists to understand other planets since the earth is part of the solar system. Scientists use the features of the earth to compare them with what other planets hold.
So far - Earth