Star Points for January, 2006; by Curtis Roelle Spectacular Venus Greets New Year The new year finds our sister planet Venus in the midst of a very favorable evening apparition. Venus is hard to miss, being the brightest object in the western sky during evening twilight. Venus is currently appearing as a very thin crescent that is only 6% sunlit. The thin crescent is visible in virtually any telescope -- no matter how small -- and can be visible in binoculars held steady. People are often surprised by their first view of a crescent Venus through a telescope because of its similarly to the moon. Through a telescope crescent Venus looks remarkably like the crescent moon viewed with the naked eye. Curious persons want to know why Venus shows a crescent shape. Venus is always closer to the sun than the earth. The average distance between the sun and earth is 93 million miles. The average distance between the sun and Venus is 67 million miles. Since Venus is closer to the sun its orbit lies completely within the earth's orbit. Therefore, Venus travels a shorter distance when making a complete circuit about the sun. The earth travels 584 million miles during its orbit whereas Venus travels 422 million miles. Its proximity to the sun also means that Venus travels around it at a faster speed than that of the earth. On average, the earth is moving at a speed of 66,600 miles per hour around the sun while Venus moves at 78,300 mph. When the speed of Venus and its shorter orbital distance are combined, we discover that Venus swings around the sun in one Venusian year that is just 224.7 earth days. By comparison one rotation of the earth takes precisely 365.26 earth days. From time to time, while traveling on its inside track, Venus catches up to and then passes the earth. The two planets will be just 25 million miles apart when Venus reaches "inferior conjunction" on January 13. This basically means Venus is passing between the earth and the sun and the two are at their closest points relative to each other. As Venus swings around the sun and gets closer to the earth its size appears to grow. As it passes between us and the sun its illumination or "phase" also begins to shrink, changing from a bulbous gibbous to a crescent shape. The best time for viewing Venus starts at 4:30 p.m. Look for a bright "star" about 20 degrees above the western horizon. Venus will continue sinking and sets within a couple of hours. The Westminster Astronomical Society will be hosting a public star party on Saturday, January 7th at the Bear Branch Nature Center (BBNC). A 7:30 p.m. program in the planetarium will also be presented ($1 for BBNC members, $2 for non-members). Planetarium reservations can be made by calling the nature center at 410-848- 2517. The outdoor telescopic viewing portion of the evening's program is free of charge.