Observing the 2005 Mars Opposition

Paul Curtin

Mars returns in October, offering a great chance for amateurs to view this planet under very favorable conditions. Unlike the 2003 apparition, which favored southern observers, this year the north will get the best view.

The crucial dates find Mars in Aries and Taurus, outshining even Aldebaran until the end of the year. See Bone or McRobert and Troiani for timelines, positions and other details. On 7 November, at opposition, Mars will clearly stand out at magnitude -2.3. Its blazing red visage will illustrate why the ancients named this planet for the god of war.

By the end of October, Mars and Earth will be within 69,400,00 km of one another, and Mars will have reached its maximum apparent diameter (20 arc seconds). Don't wait until then to begin observing, however, as you need to train your eye to distinguish the fleeting details on the Martian disk. Watching the apparent diameter increase and then decrease is also interesting, so remember to observe after opposition as well. Surface details should be visible well into early December.

If possible, view Mars with different sized telescopes to compare the resolving power at various diameters. Filters are extremely useful in picking out different types of features. In a pinch you can use 35 mm camera filters held between the eye and an eyepiece with good eye relief.

It is usually best to observe as long as possible in white light before using filters and then employ them for specific purposes. They certainly favor the trained eye and are not a magical panacea for bad viewing or inferior optics.

Try to photograph Mars either with or without a telescope. Digital technology is such that you can now outperform the amateurs (and sometimes professionals!) of yesteryear. If, like me, you are still in the age of film, Dobbins et al. is a great source for techniques.

Even if you don't venture to make a photographic record, you should attempt to draw what you see. This trains the eye and helps one glimpse details that might otherwise be overlooked. Draw only what you can confirm and keep detailed records for each drawing or photo. Price or Bone should be consulted regarding record keeping.

Whether you are a seasoned observer or new to astronomy, a favorable Mars opposition is a fascinating event. On my block it calls for a string of Mars parties dedicated to showing off the red planet to as many friends and passersby as possible. It is an excellent opportunity to introduce both children and adults to the excitement of scientific pursuit while giving them a glimpse of the beauty of our solar
neighborhood.

Bibliography

Blunck, J. Mars and its Satellites. Hicksville, NY: Exposition Press, Inc., 1977.

Bone, N. Mars Observers Guide. Buffalo, NY: Firefly Books, 2003

Cross, C. A. Mars. New York: Crown Publishers, 1973.

Crosswell, K. Magnificent Mars. New York: Simon and Schuster, 2003.

Dobbins, T., Parker, D., Capen, C. Introduction to Observing and photographing the Solar System. Richmond: Willmann-Bell, 1988.

Gillard, D., Holdaway, R. (eds.), The Astronomical Almanac, 2005. Washington: U.S. Government Printing Office, 2003.

Gupta, R. (ed.) Observers Handbook 2005. Toronto: University of Toronto Press, 2004.

Hartman, W. K. A Travelers Guide to Mars. New York: Workman Publishing, 2003.

McRobert, A., Troiani, D. “The Great Mars Appiration of 2005”, Sky and Telescope, September 2005.

Moore, P. (ed.) Practical Amateur Astronomy. London: Lutterworth Press, 1975.

Moore, P. Guide to Mars. New York: W.W. Norton & Co., 1977.

Moore, P. Patrick Moore on Mars. London: Cassall, 1998.

Price, F. The Planet Observer's Handbook. Cambridge: Cambridge University Press, 1994.

Sheehan, W. The Planet Mars, a History of Observation and Discovery. Tucson: U. of Arizona Press, 1996.