by Thomas Haeberle
A year ago, on August 27, 2003, Mars made its closest approach since early man began to gaze upon the stars. It came within a mere 34,646,418 miles of Earth, an astronomical stoneòÀÙs throw away. The tremendous popularity of this event was unparalleled since the 1986 return of HalleyòÀÙs comet. Far and wide, radio and television news programs reported about the upcoming event. The August 26th issue of theˆàDaily Newsˆàsported a huge, colorful picture of Mars on the cover, and dedicated almost two full pages to the Red Planet, including a comment from our club president, Mike OòÀÙGara.
Mars Events Galore
Astronomy clubs sponsored Mars events, attracting huge crowds around the country. Our own two Amateur Astronomers Association events were a resounding success. The August 27th event, co-sponsored by the AAA and the College of Staten Island, where it was held, drew well over 500 people, and possibly twice that number. Despite overcast skies, staff and volunteers were ready. Lined up along the walkway were over a dozen 8-inch Meade Schmidt-Cassegrain scopes manned by club members and students. A few bright stars were visible overhead, making it possible to align the telescopes and then point them at the Red Planet.
Luckily, Mars was bright and powerful enough to punch through the opaque skies and give the attendees a peek at its southern polar cap. Besides the large 16-inch Meade reflecting telescope in the College observatoryòÀÙs dome, AAA member Larry Ventura had his 12-inch Meade òÀÜgotoòÀÝ scope at the ready. I was also òÀÜvolunteeredòÀÝ to work one of the scopes, and with the help of member Joe DiNapoli, I was wowing the crowd with views of Mars.
The South Street Seaport was the site of another AAA Mars event on Friday, August 29th, where members set up about a dozen telescopes of various types (Dobsonians, C5s, C8s, etc.) to view the Red Planet. The weather was mostly cloudy and hazy, but again Mars did not disappoint. OòÀÙGara estimated a thousand people took a peek at the planet with its most prominent dark feature, Syrtis Major, coming into view. There also were two impromptu Martian observing at Carl Schurz Park that week, where several hundred passersby caught a glimpse of Mars.
AAA member Lee Baltin reported that the S*T*A*R astronomy club of Red Bank, New Jersey entertained 5-6 thousand people during the week of MarsòÀÙs closest approach. I visited the Custer InstituteòÀÙs observatory out at Southold, Long Island on Sepember 6th, and never I have seen such a turnout of people frantic to see Mars. A long line spiraled down the stairs from the observatory dome to the bottom-floor lecture hall. Custer houses a 6-inch Eichner refractor in the dome, as well as a 14-inch reflector in the back shed.
An Ever-Changing World
Observing Mars can be a challenge, and 2003 was somewhat frustrating–weatherwise at least–compared to prior years. The month of August was particularly hazy and muggy, with a lot of moisture in the air producing bad seeing. One of my best views came on the morning of July 1st; Mars looked fantastic. The large south polar cap stood out like a lop-sided bulls-eye on its 16.8″ disk. I used a pale blue filter to enhance the òÀÜsnowòÀÝ cap, and the dark bluish-looking band girdling the perimeter of the cap (see Figure 1).
Astronomer and author of òÀÜMars and Its CanalsòÀÝ, Percival Lowell thought the melting of ice-water snow caused this blue band that he called a badge of blue ribbon. What he thought was liquid water draining into the soil was actually frozen carbon dioxide subliming into vapor exposing the dark volcanic rock surface that hides beneath the polar cap (see Figure 2).
The morning of July 17th brought a conjunction of the Moon and Mars. The pairing displayed a beautiful contrast of colors: the bright orange Mars next to the grayish-white Moon against a dark-sky backdrop. Mars came within one-fifth of a lunar diameter of the Moon, hanging above it to the north, in line with the crater Plato. I easily kept the two in the same field of view using 80x magnification. The polar cap was visibly smaller than at my July 1st observation, though not too much surface detail was seen.
By September, the weather had improved, and the moment when Mars was the clearest for me came on the morning of September 6th. The air was dry and the seeing excellent. I always draw the planet first before consulting any maps or charts. As shown in Figure 3, the most prominent dark feature, Syrtis Major, was coming into view, and the features Sinus Meridiani and Sinus Sabaeus were at the center.
One For the Ages
The reason for this closer than ever approach is because the orbits of Earth and Mars are elliptical paths. These paths actually rotate through space over thousands of years, bringing a point in EarthòÀÙs orbit at its farthest distance from the Sun (aphelion) closer to MarsòÀÙs closest approach to the Sun (perihelion). ItòÀÙs kind of like the Spirograph drawing toy many of us had as a kid. Also, MarsòÀÙs elliptical orbit has become a lot more eccentric or oval over time, bringing it even closer to Earth during perihelic oppositions.
Every 15 or 17 years, Mars makes these close approaches, called favorable oppositions. There is also a long-term cycle of 79 years where the circumstances of any particular Mars opposition will replicate almost exactly. The planet was just 11,764 miles farther from Earth than this past opposition on August 22, 1924.ˆà And in another 79 years, on August 30, 2082, Mars makes another exceptionally close approach to Earth, though again falling short of matching 2003òÀÙs approach, this time by 78,487 miles. In September of 2729, Mars will come within 34,579,931 miles of our world, the best opposition in the next thousand years, and 66,487 miles closer than last yearòÀÙs event.
During the flying saucer craze of the Sixties and the Seventies, you could expect an increase in UFO reports when Mars made such close approaches. Not because the Martians had landed, mind you, but because the bright planet hung so eerily in the sky, it may have given people cause to think that a flying saucer was hovering not far away, over the city. This past AugustòÀÙs Mars approach could very well have been like a page torn from the script of Orson WellesòÀÙs 1938 radio broadcastˆàThe War of the Worlds; upon hearing it, numerous listeners panicked, thinking we really were being invaded by Martians. With the annual Perseid meteor shower blazing overhead seemingly radiating from the direction of Mars over New York City, itòÀÙs a wonder that people did not think we were under attack from Mars!