Orion is a winter constellation, it is visible in summer but not from earth because it is on the other side of the sun. It begins to appear early in the morning in the east toward the end of summer and dissapears in the west late in the winter/spring. I am not sure of the exact dates when this occurs but some tiem around the equinoxes.
Check astronomy.net image gallery for a picture of the constellation Orion. There might be one of the Pleaides there too, I haven't looked.
Concerniong The Pleaides I do not know at this time what its time table is. I'll check into it for you.
Did you look up observatorys or another web site on the internet to find your answers?

• pl and orion - mikeh - December 22, 2003 - 05:52 UTC