Mars at Its All-Time Finest
It's not enough to describe the 2003 apparition of Mars as unique. In late August, as if beckoning us to touch its enchanting, exotic shores, the red planet will reach magnitude –2.9 and will dominate the southern sky with its fiery coloration. Finally, on the night of August 26–27, Mars will be closer to Earth — if by only a little — than at any time in some 60,000 years (see "A Mars Record For The Ages").
When the broadcast entertainment industry awakens to this remarkable fact, the airwaves will be filled with replays of classic movies like The War of the Worlds and the 1938 radio hoax staged by Orson Welles. A rush not seen since the 1986 visit of Halley's Comet could overwhelm the telescope market. The event is almost a certainty to fire the public's imagination as few other astronomical events can.
But amateur astronomers already know that Mars is always a telescopic challenge. Despite its remarkable proximity this time, Mars's features will be more elusive than its next-door-neighbor status would suggest. Faced with a public that's clamoring for views at summer star parties, inexperienced observers will have a hard time impressing their audience. For Mars, an angular extent of 25.1" is as good as it gets, but that's barely more than half the apparent diameter of Jupiter.
Mars becomes almost this large every 15 or 17 years — whenever it passes closest to Earth (near opposition) within a few weeks of the date it is also nearest the Sun (perihelion). For example, in August 1971 the disk became as large as 24.9", and in September 1988 it reached 23.8". Less-ideal views come at intervals of about 2 years 2 months, as in May 1999 when it reached 16.2", and in June 2001 when it attained 20.8". Putting August 2003 in perspective, this is one of five chances (at most) in your entire lifetime that you'll see Mars so clearly.
