Star Points for August, 2006; by Curtis Roelle Mercury rising in August Mercury, Venus, Earth, and Mars -- the four planets nearest to the sun -- are known as the "terrestrial" planets because they have hard rocky surfaces. On the other hand the gas giants -- Jupiter, Saturn Uranus, and Neptune -- that turn from being gas to a liquid below crushing atmospheres. Obviously, a voyaging spacecraft equipped to land stands a better chance on a terrestrial planet than on a gas giant. And this is exactly what has happened over the years with spacecraft that have been sent forth by the U.S. and the Russians since the early 1960s to land on Venus and Mars. Mercury is the only terrestrial planet whose surface has not been visited by a spacecraft from the earth. Sure, there have been "fly bys" of Mercury. Mariner 10 actually made three separate flybys in the mid-1970s. Although NASA's Messenger mission currently on its way has plans to enter into orbit around Mercury, it is not equipped to land. Mercury has been known since antiquity as one of the "wandering stars" in the night sky we now call the planets. Mercury is named after the Roman god who is the son of Jupiter (Hermes, son of Zeus to the Greeks). His mother is Maia, the eldest and most beautiful of the seven nymphs known as the Pleiades. Thomas Bulfinch (1796- 1867) described Mercury as "the god of science and commerce, patron of travellers and rogues, vagabonds and thieves." Not one of the most flattering descriptions. Mercury is the most difficult of the naked eye planets to observe. Its orbit hugs the sun and so it never wanders very far from it in our sky. Therefore, it is usually up during most of the day. However, to view it in a darkened sky Mercury must be observed in twilight either after sunset or before sunrise -- depending on which side of the sun Mercury happens to be. Whereas most people have probably viewed the brighter planets -- Venus, Jupiter, Saturn, and even Mars -- at one time or another, even though they might have assumed they were merely bright stars, Mercury does not easily lend itself to accidental observing. When placed best for viewing Mercury has a narrow observing window -- usually less than an hour -- on days it can be glimpsed low in the twilight. An observer must want to see it in order to successfully observe Mercury. Luckily for us early August holds a splendid opportunity to view Mercury in the early morning sky at dawn. As it brightens daily for a time it also gets higher. Even better, bright Venus acts as a signpost for spotting Mercury. If you're up around 6 a.m. this week look for a spot with a clear view of the eastern horizon where the sky is getting very light. You'll need to find a view not blocked by trees, hills or buildings. There, hovering above the horizon is the bright planet Venus hovering above the horizon. If you look just below it you will see much fainter Mercury. I recommend using binoculars to help you find Mercury. Point them at Venus and adjust the focus for both of your eyes. Now slowly move them downward and look for a much fainter star-like object; that is the planet Mercury. Once found you can keep tabs on it as the sky brightens. Note where Venus is with respect to distant objects on the horizon and come back later with another cup of coffee to see if you can still locate Mercury. How long can you still see Mercury until the daylight overpowers it? Can you see Mercury without the binoculars? Drop me an e-mail and let me know how you did at StarPoints@GMail.com.