Jupiter is one of the planets. It is named for the highest deity in the Roman pantheon.
Jupiter is conspicuous and easy to recognize when you know what to look for, and is considered the most interesting planet to view through binoculars. It is not so bright as to instantly draw attention, but it is a good deal brighter than the brightest star. It is in fact the fourth brightest object in the sky (the others being the Sun, the Moon, and the planet Venus). Jupiter is not only brighter than any star, it also shines more steadily. Jupiter is visible in the sky about half the time, and is often high up and clear of surrounding houses and trees.
As of February, 2007, Jupiter is visible in the eastern sky before sunrise, and even in the early stages of dawn.
Through any pair of "real" binoculars (any binoculars that an adult uses for birding or hunting will do; they should be at least 7 power; a "spotting scope" is even better), you can see that Jupiter is not a star, but shows as a tiny round circle; astronomers say it has a visible "disc." Jupiter through binoculars looks about 1/5 the size as the Moon looks without binoculars. You can't see any of the dramatic markings that you see in photographs made by astronomers, but you can see that it is a round dot.
The exciting thing about Jupiter is that usually you will see two, three, or four little "stars" near it that are all lined up in a straight line, with each other, and with Jupiter. If you watch it night after night, these "stars" will change their position relative to Jupiter, but you almost always will see several of them and they will always be lined up. These are four of the satellites of Jupiter.