Venus orbits between the Earth and the Sun, so from our vantage point we usually see it in the sky near the spot where the Sun has either just set, or will rise soon. You'll only be able to see it for either a couple hours after sunset or a couple hours before dawn, depending on where it is in its orbit. Venus shines more brightly in the night sky than anything except our Moon. It's an incredibly bright, dazzling yellow spot of light. When it's up, it will be the brightest dot in the sky.
Venus is dazzling to the naked-eye. But, because of it's bright, reflective cloud cover, no surface features are visible through a telescope. You can, however, see that Venus goes through phases like our Moon. Just like the Moon, it will go from full, to gibbous (partially full), to a quarter, and finally to a crescent. However, unlike our Moon, Venus orbits the Sun. So it changes its distance from us, and hence its apparent size, as it goes through its phases. Our Moon is brightest when it's full. But when Venus is fullest, it's on the opposite side of the Sun from us, and it appears very small. When it is a thin crescent it is closest to us, so it appears at its very biggest and brightest.
Galileo was the first to notice this. From his observations he deduced that Venus must be orbiting the Sun, not the Earth like the Moon does. His arguments were irrefutable (and correct), but the idea that the Earth wasn't the center of the universe so angered the Church that they put Galileo under house arrest (virtually in prison) for the rest of his life.
The diagram shows Venus going through its phases. When you observe it, see if you can tell in which phase it is. If you are observing Venus in its bright but thin crescent phase, look carefully at the tips of the crescent, called "cusps". Sometimes these appear to extend a bit beyond halfway round the planet. This effect is caused by Venus' thick atmosphere bending the sunlight around the disk.
Although Venus is about the size of the Earth, you wouldn't want to live there. Its thick atmosphere of poisonous gases has caused a runaway greenhouse effect, where sunlight goes through the atmosphere but can't bounce back out. So Venus has become the hottest planet, with a surface temperature of about twice as hot as your oven. There is no water on Venus, and it may have active volcanoes and fierce lightening storms. It's surface pressure is so great that you would be immediately crushed by the atmosphere. Even our metallic space probes have difficulty surviving a trip to its surface, so it's unlikely we'll be sending any manned probes for a while.
Sketch Venus and its phases at various times. Note the date.
Approximate position of Venus in the early evening hours:
Spring 1996 west
Summer 1996 not visible
Fall 1996 dawn
Winter 1997 dawn
Spring 1997 dawn
Summer 1997 west
Fall 1997 west
Winter 1998 not visible
Spring 1998 dawn
Summer 1998 dawn
Fall 1998 not visible
Winter 1999 west
Spring 1999 west
Summer 1999 low west
Fall 1999 dawn
Winter 2000 dawn
Spring 2000 not visible
Summer 2000 low west
Fall 2000 west
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