Bright, beautiful Venus graced the southwest sky last evening. Named by the Romans for their Goddess of Love, Venus is the brightest object in the night sky (other than our moon). Since its nearly circular orbit is closer to the sun (an average radius of 49 million miles, compared to 93 million miles for Earth), from our vantage point, Venus never ventures more than 47 degrees from the sun. As a result, it is at its brightest just before dawn (in the southeast sky) or just after sunset (in the southwest sky) and has long been known as the Morning Star or Evening Star, respectively.
Our sister planet, which is only slightly smaller than the Earth, has become the poster child for greenhouse warming. Venus has a dense atmosphere of carbon dioxide, which is primarily responsible for its surface temperature of 400 degrees C; it is actually warmer than Mercury even though its orbit is nearly twice as far from the sun. Another unusual feature of Venus is its slow rotation; while it orbits the sun every 225 days, it takes 243 days to rotate on its axis. Furthermore, contrary to the other planets, it rotates clockwise; astronomers suspect that this slow, reverse rotation may have resulted from a past collision. Venus, our beautiful but odd goddess in the sky.
