For the planets that we know about, you can visit Spaceweather.com or currentsky.com to see what astronomical sights are easily visible.
If you are referring to an unknown planet, then I have bad news for you; everything that is visible with the naked eye has already been cataloged and identified. If a new planet is discovered, it most probably will not be visible without BIG telescopes.
Planet X was a hypothetical planet which was searched for after the discovery of planet Neptune. Deviations in the orbit of Neptune led some astronomers to believe that there was another planet further out, but these original observations of Neptune turned out to have errors in them and a further sizable planet was never found.
Tonight on September 4th, 2010, the bright object you see in the eastern sky is likely the planet Jupiter. Jupiter is one of the brightest objects in the night sky and is often visible to the naked eye.
There isn't such a planet called planet trio, not in our solar system at least. A planet trio refers to three planets seen in the same area of the sky, tightly bunched as viewed from earth. For example, you may see mercury, Venus and Jupiter all close together in the sky and could call it a planet trio.
Planet X is a hypothetical planet beyond Neptune that has been proposed to exist in the outer reaches of our solar system. It has not been directly observed, but its existence has been theorized to explain anomalies in the orbits of outer planets. Scientists are still searching for evidence of such a planet.
The planet will still rise in the east and set in the west. The "retrograde" motion is relative the stars, and to its previous position; you won't see it move moment to moment, but night after night, you can see that it normally creeps one way across the sky, but for a couple of weeks near the conjunction, it will seem to creep the other way across the sky before going back to its normal direction.
There is no "Planet X". See links.
There is no evidence that planet X exists
Venus
That's Venus, the most brightest object in our sky after Moon.
Venus is the brightest planet in the sky. It is often referred to as the "evening star" when visible in the western sky after sunset or the "morning star" when visible in the eastern sky before sunrise.
It depends. In many cases the first "star" you see in the evening sky is Venus, which is a planet.
Planet X is an informal name for the planet Pluto [See related question] however in later years it has come to be named as the hypothetical and 2012 disaster planet called Niburu [See related link].
Planet X is an informal name for the planet Pluto [See related question] however in later years it has come to be named as the hypothetical and 2012 disaster planet called Niburu [See related link].
You wouldn't be able to see the sky past the thick atmosphere. It would be quite foggy on the surface, but you would be able to see the rocky surface of the planet through the dense mist.
what keeps planet earth from fallin out of the sky
sometimes you can see the planet venus!
Right (November 2009) you can see Jupiter, as a bright planet (looks like a star). At sunset, Jupiter is near the meridian, i.e., near its highest point. If you have a clear sky, just look out for the brightest star you can see.