Mars Mania: Your Guide to a Close Encounter of the Planetary Kind
August 2003 :
Note: This article may contain outdated information
This article was published in the August 2003 issue of The Skyscraper and likely contains some information that was pertinent only for that month. It is being provided here for historical reference only.
"No one would have believed in the last years of the nineteenth century that this world was being watched keenly and closely by intelligences greater than man's and yet as mortal as his own; that as men busied themselves about their various concerns they were scrutinized and studied, perhaps almost as narrowly as a man with a microscope might scrutinize the transient creatures that swarm and multiply in a drop of water. With infinite complacency men went to and fro over this globe about their little affairs, serene in their assurance of their empire over matter....No one gave a thought to the other worlds of space as sources of human danger, or thought of them only to dismiss the idea of life upon them as impossible or improbable. It is curious to recall some of the mental habits of those departed days. At most, terrestrial men fancied there might be other men upon Mars, perhaps inferior to themselves and ready to welcome a missionary enterprise. Yet across the gulf of space, minds that are to our minds as ours are to those of the beasts that perish, intellects vast and cool and unsympathetic, regarded this earth with envious eyes, and slowly and surely drew their plans against us. And early in the twentieth century came the great disillusionment."
So begins "The War of the Worlds," the 1898 sci-fi classic by H.G. Wells. This book was the first science fiction novel I ever read. I remember reading it non-stop from cover to cover because I was so fascinated with the possibility of life on other worlds. Too bad most literary and movie extraterrestrial life-forms almost always seem determined to exterminate us!
Did Mr. Wells dream up the idea of intelligent beings residing on Mars? I'm afraid the credit is not due him. Wells relied upon astronomical studies of his day for the premise. It all began in 1877 when Italian astronomer Schiaparelli reported observing "canali" on Mars. "Canali" means channels. However, when the word was translated into English they were simply called "canals." Canals implied intelligent construction, and thus began the speculation on the Martian builders.
At the turn of the 20th century, U.S. astronomer Percival Lowell began a study of Mars. With the guidance of the Harvard College Observatory, an observatory was erected on a hill in Flagstaff, Arizona, where the seeing was quite good. It is still a working observatory today, named Lowell Observatory in his honor.
Lowell also observed these peculiar markings criss-crossing the planet. He conjectured that the Martians had an impressive irrigation system to carry water from the frozen polar caps to the arid desert regions near the planet's equator. Lowell wrote, "Irrigation, and upon as vast a scale as possible, must be the all-engrossing Martian pursuit." But alas, there are no canals on Mars, or any Martians either, as far as we know. So what really did Schiaparelli and Lowell see?
No one knows! Some astronomers have speculated that under ideal observing conditions these two astronomers may have detected craters on the Martian surface. It could have also been subtle difference between bright and dark areas. Their brains may have played "connect the dots" with these features to produce the "canals." Only with today's modern telescopes and electronic equipment can one image craters and volcanoes. So it appears the old observations may always remain a mystery.
(I visited Lowell Observatory in 1981 and had the opportunity to observe Saturn through the magnificent 24-inch refractor. It was an awe- inspiring image I will never forget. My only regret is that Mars was not the object of our attention that evening. I can only imagine what images this great refractor provided to Lowell in the clear and stable air of Flagstaff. Would I have succumbed to the Lowellian Syndrome as well?)
Since Lowell's time, many space craft have orbited the red planet. (Currently there are two spacecraft orbiting Mars and taking detailed images, the Mars Global Surveyor and Odyssey. Four more spacecraft are on their way, including three landers and two rovers!! More about that later.) Unfortunately they did not confirm Lowell's observations. Mars is a bleak, desert-like planet that is also very heavily cratered. There are huge volcanoes, global dust storms, and great sand dune fields. In addition, what look like dry river beds abound on the planet. Could Schiaparelli and Lowell have seen these? Not from Earth they couldn't!! Even the craters don't match up to any of the drawings Lowell made of round regions he called oases, where "canals" appeared to merge.
Besides, Mars has been dry for a long, long time. It seems Mars once had an abundant supply of flowing water on its surface. Somehow much of it was lost to space, whereas the remainder may remain trapped beneath the surface as permafrost. The polar caps also contain much water ice, though it is mixed with a lot of carbon dioxide. There is no liquid water on Mars. The atmospheric pressure is so low that a water droplet would explosively evaporate if exposed to the Martian environment.
Prior to 1976 faint hope still persisted that Mars supported some form of life. I'm sure that belief drove the research teams who oversaw the two Viking landers that successfully touched down on the Martian surface in July 1976. Among other experiments, the Viking landers tested the soil surrounding the space craft for microscopic life. The results proved negative, though some biologists and chemists say "inconclusive." A television camera on board scanned the immediate area. No Martian, large or small, sauntered past the lander. I think many researchers would have indeed been shocked if the camera had revealed a curious creature peering into the lens. Our outlook on life in the universe, as well as our place in it, would have dramatically changed.
What continues to draw us to Mars? Is it because we still believe life may once have flourished upon or beneath its now lifeless terrain? Spacecraft images and sensors may provide a wealth of data, but nothing can compare to the experience of seeing first hand even a fleeting image of some Martian surface features through a backyard telescope.
Normally Mars is quite a challenge to observe from Earth. Its usually small appearance through a telescope makes it difficult to discern much surface detail, other than a polar cap or a large feature like Syrtis Major or the Hellas Basin. However, Mars' close encounter with our planet on August 27 will provide the best view of this desert world in the next 15 years, and it won't be this close again until August 28, 2287. So don't make any excuses. Get out those dusty telescopes and put them to good use. If you don't have a scope, see the end of this column for details of a special Mars lecture and viewing session at Seagrave Observatory in September. You won't want to miss it!!
Mars' close encounter will provide views of surface detail that many of us have only glimpsed during past, less favorable encounters. What we will still need is some good observing conditions. Usually I would say perfect or ideal, but Mars' increased image size will more than compensate for some "imperfect" seeing. In fact, the best views of any of the planets I have observed have come under hazy sky conditions. This brings stability to the air. The telescopic image must be steady under medium to high magnification, else the details will blur into indistinct and formless features. Your telescope and mounting must also be sturdy. Any motion of the scope under the magnifications necessary for observing Mars will be quickly transmitted to the image. A clock drive to counter the Earth's rotation is also recommended to keep Mars' image centered in the eyepiece at all times.
When this column appears in mid to late August or early September, Mars will be the bright red "star" in the southeastern sky around 10:00 pm. You shouldn't have any difficulty finding it. On the 28th when Mars is opposite the sun in the sky (called "opposition"), it will shine at magnitude -2.9, the brightest it can ever get. On that night Mars will be due south at midnight about 30 degrees above the southern horizon, a red beacon among the stars of Aquarius.
Even if you have had little experience observing through a telescope, Mars' larger than usual image size will reveal more surface features than it has during past close encounters.
Unless a global dust storm completely covers the planet by the time this article is printed, the first feature that will catch your eye will be the south polar cap. It is conveniently tilted towards the Earth, giving us a great view. Watch it carefully over the coming weeks. When spring began in Mars' southern hemisphere on May 5, the south polar cap began to melt. Summer solstice occurs on September 29, providing more sunlight to shrink the cap. If you begin observing Mars as soon as you read this column, you should soon notice the south polar cap shrinking as time progresses. Ideal observing conditions may allow you to see some irregularities in this cap. During past oppositions dark rifts have isolated portions of the cap as detached segments. The south polar cap may even disappear entirely.
The rest of the planet will appear as a rust-colored beach ball. Several dark features can also be seen. These are the underlying rock exposed by the shifting sands during intense dust storms. During the Mars opposition back in 1988 under favorable observing conditions with my six- inch reflector at 300 power, I was able to see Mars as a soft peach color, while the dark areas appeared as a forest green. I'm sure the dark areas appeared green due to contrast. I can see how the astronomers of old thought the dark regions were areas of vegetation. I even captured a decent image of Mars on film at that time. To enhance the view try red and yellow filters that fit your eyepieces. They often improve the contrast and permit more detail to be seen.
And just a few weeks ago at 3:00 in the morning my wife and I got our first look at Mars during this close encounter with my six-inch reflector. The south polar cap was very big and bright. Anyone could have detected it. We also saw some indistinct dark markings on the surface. I can't wait to see it through the Clark refractor at Seagrave Observatory.
Be aware that the Martian day is 24 hours and 37 minutes long, while our day is 24 hours long. This has an effect on your observation of surface features. If you see a dark feature on Mars' central meridian (an imaginary line that bisects the planet) one evening at 12:00 midnight, the next evening it won't return to the central meridian until 12:37 am. On the following night it would arrive 37 minutes later. Therefore, to ideally observe the same piece of Martian real estate on the central meridian each successive night, you must wait an additional 37 minutes each evening.
You should begin watching for dust storms immediately. As of this writing, late July, a dust storm had already begun around July 1 in the Hellas Basin. This deep meteor impact basin is a prime location for dust storms to begin. The global one that prevented our observations of Mars in 2001 started here. This time, fortunately, it began to subside two and a half weeks later.
The dust storms begin as small yellow clouds that grow and grow and can eventually blanket the entire planet. Whitish water vapor clouds can also be detected, as well as bright spots of frost. These features are all possible to see, though you will probably have great difficulty observing anything more than the south polar cap and some of the dark surface features with a six inch or smaller telescope. That is one reason why our observatory will host some public nights in September. The other reason is .... we enjoy sharing the beauty of the heavens with you! More about our open nights later.
In conclusion, be patient when observing Mars. The disk of the planet, though the best in 60,000 years, is still relatively small. Features will be easier to detect than during past close encounters. Wait for steady seeing conditions. Don't try observing Mars if, when you look through the telescope, it seems like you're observing from the bottom of a swimming pool! Take your time in observing this fascinating planetary neighbor and your efforts will be well rewarded. The August 2003 issue of Astronomy magazine and the July issue of Sky and Telescope magazine each contain a fine map to aid you in identifying Martian surface features.
In addition, remember there are four spacecraft heading toward Mars. One is a Japanese craft called Nozomi, whose telemetry has been lost. Its encounter with Mars is in December. Another December rendezvous is by the European space Agency's Mars Express orbiter, with a British lander called the Beagle 2. Arrival is on the 26th. The United States has two Mars Exploration Rovers en route. The Spirit and Opportunity touch down on January 4th and 25th respectively. These two rovers are more advanced versions of the Sojourner rover that traversed the Martian landscape back in 1997 as part of the Pathfinder mission. They'll be much in the news once they arrive at Mars.
This column has presented only a simple introduction to Mars observing. You will not duplicate the observations of Percival Lowell, nor will your view be anything like the electronic images recorded by astronomers you might see on television or when you surf the net. You will, however, be able to take a knowledgeable glimpse of an alien world that inspired generations of astronomers and science fiction writers alike to ponder the existence of Martian life-forms. So drag out those telescopes and expose them to the light of the universe. H.G. Wells imagined the Martians scrutinizing the Earth. We don't want the observations to be one-way now, do we??
Planning is currently underway for Skyscrapers, Inc to host several special Mars observing programs in September at Seagrave Observatory. Watch this news media for dates and times when the details have been finalized.
