 | Martin Ratcliffe
is President, International Planetarium Society (2001-2002) and Director of Theatres and Media Services at Exploration Place and has been involved in all aspects of program development for the Boeing Cyberdome Theater and the Simulation Center. The CyberDome theater continues development of fully interactive shows in immersive domed theatres. Prior to moving to Wichita, he directed the Buhl Planetarium at the Carnegie Science Center in Pittsburgh, PA from 1991 to 1997. Martin co-developed the world's first interactive Planetarium in Armagh, N. Ireland. Martin is also an accomplished writer and monthly columnist for the national magazine, "Astronomy". He also films total eclipses of the Sun for television, and enjoys astrophotography. He is a past Council member of the British Astronomical Association. He earned his Bachelor's of Science degree from University College London (England) in Astronomy. Martin is adjunct professor of Astronomy at Baker University in Wichita, Kansas. |
Astronomy
2003-10-01 11:56:00
Keeping your eyes on the skies
ANSWER: There is a lot happening in the skies over Wichita in the next couple of months. Regular sky watchers keep track of what's happening each month by, for example, reading my column in the widely available magazine, "Astronomy", where I review each month's happenings along with beautifully illustrated star charts. Below I describe two events, Mars, and a total eclipse of the Moon on November 8. Mars, of course, remains visible throughout the rest of this year, though it will become dimmer as Earth pulls away from the red planet. As nearly everyone knows by now, Mars was at its closest point to Earth on August 27. On that date, it stood 34.6 million miles from Earth, the closest since the Stone Age, some 60,000 years ago. Mars and Earth come fairly close every two years in what is called "opposition". "Opposite to what?", you may ask. It's opposite the Sun in our skies, which places the planet due south at local midnight and at its highest above the horizon, the best time to view any planet. Following the date of "opposition", on August 27 in the case of Mars, the planet moves into the evening sky and is visible after dusk. All planets, stars, moon and Sun rise in the east, so in the early evening during September that is where you found Mars. During October, the planet will be high in the southeast or south. The later in the evening you view, the farther Earth has turned, thus placing the planet farther west (earth turns from west to east causing the sky to move east to west). Some people may be surprised that Mars is still around, considering the headlines in August like Mars closest TONIGHT!". The impression this headline seems to convey to is that the following day, Mars would zoom off under some previously unknown force never to be seen for a few years. In fact it is us, our planet Earth, that is doing the zooming. We move around the Sun faster than Mars, rather like two cars on a racetrack. The inner one moves faster. Gravity works the same way, and causes the Earth to move faster, and every two years we overtake Mars. We are closest to Mars for a brief moment, then gradually move away, slowly at first, then as we round our orbit, the departure speed appears to increase. The next big event is the Total Eclipse of the Moon on November 8. This is the second total eclipse of the moon this year, quite an unusual event. However, the first one, on May 15, was clouded out for local Kansans. So let's keep our fingers crossed for November 8. The Moon will rise already eclipsed shortly after 5:30 p.m. Central Standard Time. As the sky darkens, the Moon crawls into the Earth's shadow. You can see the geometry in action - the Sun has just set exactly opposite where the Moon is rising, and you, on Earth, are in the way, blocking sunlight from falling on the Moon. The Moon will be immersed fully in the shadow at 7:06 p.m. During this total stage, the Moon typically turns a bright orange, comparable to the bright orange color of Mars that will be visible high in the south on the same night. The total stage ends at 7:30 p.m. as the Moon slides away from Earth's shadow. This eclipse is quite short because the Moon is passing through the lower edge of the Earth's shadow. Look also for the Pleiades (Seven Sisters) star cluster to the left of the eclipsed Moon, and below, the bright star Aldebaran, a red giant star that marks the eye of the Bull in the traditional constellation of Taurus. You can try to photograph the eclipse using a digital or film camera. Just make sure the camera is firmly mounted on a small tripod for stability. More details about the eclipse can be found on a web site at http://www.mreclipse.com/. For activities in 2004, I have just completed the annual edition of Astronomy magazine called "Explore the Universe". This special issue reviews the entire year of events next year, and is in its tenth year of publication. Try a local bookstore for a copy, and it can be your guide for the full year. Not mentioned here are meteors showers, Jupiter and Saturn. For those and more, go to Astronomy.com.
