The three normally brightest objects in the night sky are the moon, Venus and Jupiter, not counting the rare fireball or the odd alien spacecraft. From March 10 to March 14, Venus, No. 2 brightest, passes Jupiter, No. 3.
When a planet or the moon passes another object, astronomers refer to that as a conjunction. Technically, the conjunction is the point in time when the two objects are on the same north-south line, or in astronomical parlance, have the same right ascension. Right ascension is the astronomical equivalent of longitude on Earth. That occurs on March 14, but their closest approach takes place the previous evening.
This isn't a particularly rare event, but it is visually spectacular. Since Venus orbits closer to the sun than our planet does, we can only see it within about 45 degrees of the sun. Venus is the “evening star” when we see it after sunset in the west, as it is now, and is the “morning star” when we see it before sunrise in the east, as it will be from late June through the rest of 2012.
You can never see Venus due south, unless the sun also is up, and you can never see it in the sky opposite the sun. But both of those conditions can occur with Jupiter. Jupiter was in opposition, opposite the sun in our sky, on Oct. 29. Since that time, the sun and Jupiter have been slowly moving closer together. Actually, it's Earth's orbit that is taking us toward the opposite side of the sun compared to Jupiter, but from our point of view it's as if the sun is slowly creeping eastward toward Jupiter.
Venus moves eastward with the sun — again due to Earth's orbit — and it passes Jupiter on March 14. It will be quite a display in the evening sky. Start watching each evening now as they slowly move together.
In the distant past, if Jupiter, the king of the Gods, visited Venus, the Goddess of Love, that likely would have been interpreted an astrological sign for a royal birth somewhere. Now, it's just a cool sight in the evening sky.