There is no "Planet X" that has been scientifically confirmed. The term "Planet X" has been used historically to refer to a hypothetical planet beyond Neptune, but no such planet has been discovered.

There are many reasons why you might be asking this question. Here are some possibilities:

* You are thinking about Pluto: Pluto was once considered the ninth planet, and some still call it that. However, it was reclassified as a dwarf planet in 2006. Pluto can sometimes be seen with a telescope, but it's quite faint.

* You are thinking about a hypothetical planet: There have been ongoing searches for a potential "Planet Nine" that might be influencing the orbits of some objects in the Kuiper Belt. But, as of now, no such planet has been observed.

* You are interested in other planets: If you are interested in seeing planets in the sky, Venus and Mars are the easiest to spot with the naked eye. Jupiter and Saturn are also visible, but they require darker skies. You can find detailed information about when and where to look for planets in astronomy apps or websites.

If you can provide more information about where you heard the term "Planet X," I may be able to help you further.