By Calvin L. Chrisman
Mars has been getting closer to Earth and is becoming quite prominent in the night sky. It is shining with a brilliant red-orange hue. Currently, it is rising about 7:00 p.m. and is at its highest around 2:00 a.m. By the end of the month, it will rise near sunset and cross the meridian (its highest point) near midnight. At that point, it will shine at a magnitude of -1.3 which is almost as bright as Sirius, the brightest star in the sky. Remember that negative magnitudes are brighter than positive ones. As February and March pass by, Mars will begin to fade as it moves away from Earth. Between now and then, it will be a beautiful jewel in our night sky.
Mars is roughly one-half the size of Earth. It has a thin atmosphere and two moons, Phobos and Deimos, which may be captured asteroids. It has been regularly speculated on in science fiction and by scientists with varying degrees of accuracy. It has no canals (sorry Percival Lowell) and no green men (sorry science-fiction writers everywhere), but we have found signs of water ice as well as erosion and sediment that point to earlier periods of liquid water. We are steadily gaining greater knowledge of its geological history, composition and topography. It is currently host to three orbital explorers and a number of landers and rovers. To date, we have found no signs of life, either microbial or otherwise, but the search continues.
As Mars continues to rise earlier in the evening, Jupiter is setting earlier. For those of you with telescopes, this will be the last time to observe Jupiter and its moons for a while. It is still visible in the west, but will set shortly after sunset by month’s end. This is a function of its orbital movement, but is also caused by the shorter nights we begin to experience after the winter solstice, which occurred on December 21, 2009. Because of Jupiter’s brightness, many will notice it and assume that it is Venus, sometimes known as the evening star. Venus is not visible at the present. On the 11th of January, Venus will reach superior conjunction, meaning it will be directly behind the Sun from Earth. It will not be visible again until February. Finally, Saturn is again visible in the night sky. It is rising about 11:30 p.m. but will rise two hours earlier by month’s end. Its ring system, which was edge-on to the Earth last summer, is again tilted to our view and so presents an interesting and attractive sight in small telescopes.