It was during the first year of our present century, while the northern hemisphere of the Earth was experiencing winter, that a brilliant reddish star could be seen amidst the bluish-white luminaries of the familiar constellations in the night sky. This particular star was conspicuous not only because it was bright but because it was not usually there like the rest of the stars. People who saw it shining over the snowy winter landscape knew although what it was because they had been informed about it in advance by magazines and local newspapers. Fathers took their sons and daughters out into the open at night to look at it, and teachers pointed out this wondrous red wandering star to their pupils. The newspapers had told of its waxing, of the date when it would shine brightest, and that it would slowly wane during the subsequent weeks thereafter until once again it would be out of view from the night sky. Named after the ancient Roman god of war Mars, hanging in the sky with it ominous reddish hue, has long been a source of superstitious apprehension. Hence, the symbol for Mars is a warrior's shield crossed by a spear. It was only in this century that essentially for the first time people looked up to the Red Planet without the associated fear of earlier ages. Instead, it was regarded with intense curiosity and intrigue, mixed with a strange kind of altruistic hopefulness. Instead of anticipating news of strife and unrest, people anxiously waited for the latest news from a source which previously had rarely been considered noteworthy, the mountain top astronomical observatories.
For over 300 years astronomers have been trying to solve the mysteries of the Red Planet. Unlike Venus, veiled in silky clouds, Mars is an excellent planetary object for telescopes. The planet's gleaming white polar caps, ochre deserts, dark areas, and two asteroidal moons have long been a challenge to the speculating observer. Mars revolves around the Sun once every 687 or so Earth days in an orbit that averages 142,000,000 miles from the Sun, compared to Earth's 93,000,000 miles, and appears in its most favorable position for observation, called opposition, once approximately every 790 Earth days. This is when it is directly opposite of or 180 degrees from the Sun and appears over the local meridian at midnight. Because of the distinct eccentricity of its orbit the distance of Mars from the Sun varies by a range of 28,000,000 miles. Consequently its opposition distance, and its apparent angular diameter as seen from Earth at different oppositions, varies considerably. Unfortunately for northern hemisphere observers the nearest oppositions, which are best for viewing, are less favorably placed for viewing because they almost always occur near the southern limit of the ecliptic, hence low in our night skies. The viewing of stellar objects at low sky positions is almost always affected adversely by atmospheric turbulence, which makes for poor seeing in a telescope. The closest oppositions of Mars occur on the average of once every 15 to 17 years. This planet, which is intermediate in size between the Earth and Moon, is almost always visible from Earth although it becomes periodically lost from view due to the Sun's glare when it is on the far side of the solar orb. In its vital statistics Mars is one sixth the volume of Earth and about one-tenth as massive as the latter. Its gravity is about 38% of the Earth's so that if your weight on Earth is 100 pounds you would weigh 38 pounds on Mars. The planet's equatorial diameter is 4,218 miles, compared to Earth's 7,926 miles, respectively. The orbit of Mars is inclined about two degrees to the ecliptic.
Even though Mars has been scrutinized through the telescope for centuries, it was not until fairly late in this century that a relatively thorough close hand examination of the planet was undertaken by virtue of space age technology. Much has been learned and many questions have been answered about Mars since it was recently visited by robotic space probes sent from Earth. The mysterious enigmatic green areas and elusive canals, long time curiosities to Earthbound observers, have been satisfactorily explained as illusional phenomena. Yet at the same time a host of new questions have been raised. One of the most intriguing discoveries is the presence of a considerable amount of surface erosion caused by flowing water and flooding, an evidence that the Martian environment as originally created abounded with water, a dense atmosphere and a much milder climate than at present. No life, although, like that which is found on the Earth was evident. The existence of massive shield volcanoes not unlike those of the Hawaiian Islands, although much larger, was another interesting find. Also in recent revelations is a potpourri of craters on the surface of Mars indicating a period of cataclysmic bombardment by giant meteorites not unlike that evidently experienced by the Moon. Except for possibly the largest craters, none of these remarkable details were ever distinctly visible via Earthbound telescopes.
By far, the single most significant issue that has surrounded the enigma of Mars has to do with the question of life. Is there, or has there been, life on Mars? Close observation of surface markings on the planet show that a day on Mars lasts 24 hours, 37 minutes, and 23 seconds, to be precise. Clouds, polar ice caps, mountains, canyons, seasonal changes, all together tend to make us think of Mars as a very Earthlike place. With its axial tilt only slightly greater than that of Earth Mars had long been considered to be a smaller version of Earth Many have taken for granted that this resemblance extends to the existence of life and possible habitation by intelligent Martian beings, as evidenced by the observed canals on Mars made famous in the last century by the Italian astronomer Schiaparelli and supported by others including the American astronomer Percival Lowell in Arizona. Later on the Hollywood film industry maintained the impetus. Certainly this question of life has made the interest in Mars all the more intense. The history of man's belief about Mars, especially in this regard, makes for interesting reading. Famous astronomers past and present have proposed fascinating notions about life on Mars. Since the beginning of man's imaginings about extraterrestrial life Mars has been considered the prime candidate for such a discovery, although the concept of extraterrestrial life and the controversial assumptions that support it presuppose the theory of evolution which in itself denies the notion that the Earth is particularly special in its cosmic context and as an abode of life. Consequently, man's search for life in outer space is energized by a basic philosophic and probabilistic outlook which is followed by such expectations, namely that if life evolved here why not elsewhere?
There is documented evidence that the Earth has in fact been visited by beings from beyond our world. Even though this evidence is of a superior quality it is not the kind of evidence for life among the stars that is taken seriously or sought after by promoters and researchers who have spent countless millions of dollars in their search for extraterrestrial, or, misplaced life. Furthermore, there is not even a qualitative consensus among scientists as to what, by definition, life truly is. In the Bible, which tells us much about life, God is clearly revealed as the giver of life. Dissenting scientists will argue that this is not the kind of life that should be discussed. Notwithstanding, all life does indeed come from the Creator thus it has a definite source, abode, and purpose. In due process Earth has proven to be unique as an abode of living creatures and as a most suitable place for such inhabitants including man, as it is written: For thus saith the Lord that created the heavens; God himself that formed the earth and made it; he hath established it, he created it not in vain (waste), he formed it to be inhabited: I am the Lord; and there is none else -Isaiah 45:18. Thus the Earth is disclosed in Divine revelation to be a unique place insofar as human, animal, and plant life is concerned. It is angels, fixed and fallen, not men from another planet who represent life in outer space and which are often associated with the stars in Scripture, and who have their probable habitation among the stars (planets) and who are the visiting advocates of Earth. These beings, as examined in the light of man's definition are not even alive. The very author of life Himself does not metabolize, reproduce, or even grow. Finally, the ultimate visitation from that realm not of this world was, Christ himself, who died at Calvary.
The failure of fine resolution close-up photography, as well as molecular and metabolic experiments aboard the Viking landers which set down on the Martian surface in 1976, to find any kind of life whatsoever represented a devastating blow to exobiologists. After the unsuccessful search for life via the Viking missions public interest in Mars subsided dramatically. By the same token it has been realized that the principles most commonly assumed in the study of geology here on Earth do not appear to apply on Mars either. Careful Martian studies have forced a different interpretation on many accounts. Interesting enough, a subsequent scrutiny of the Viking photos revealed a number of artificial appearing features on Mars. Two significant unmanned missions sent to Mars since the Viking program, which included plans for closer investigations of these features, were mysteriously lost, hence the exact nature of the anomalous surface features remains a most intriguing mystery.
Even though Mars evidences a degree of Earthlikeness, the present harsh reality of its environment was not so evident early on. As it turns out, Mars is a very cold world with daytime temperatures on the equator rarely exceeding the freezing point of water. The Martian atmosphere is so thin that its surface barometric pressure is only about 1/100th of that on Earth at sea level, hence the air pressure at the surface of Mars approximates that of Earth at about 20 miles aloft. On Earth nearly three- fourths of the atmosphere lies below the level of the summit of Mount Everest, a lofty perch not even six miles high, where a man can barely breathe. To a visitor on Mars wearing the necessary pressurized outfit the deep, almost dark, alien sky would appear pinkish in hue from the dust swept up by the tenuous yet fierce desert winds. The exceeding desolation of this inhospitable Martian wasteland would far surpass that of anything known on Earth. There is evidence that both Earth and Mars had denser atmospheres in a previous age. Mars and Earth have almost the same land area, only because the latter is mostly covered by water.
No portrait of Mars would be complete without a few notes about the planet's two tiny attendant natural satellites. Of the many pieces of cosmic debris that have evidently impacted Mars in the past, two of these appear to have escaped collisions with the planet and survived to become the planet's pockmarked potato shaped moons, Phobos (fear) and Demos (terror) after the chariot horses of Mars in Greek mythology. These were both discovered in 1877 by the American astronomer Asaph Hall with the aid of the 26-inch refractor at the U. S. Naval Observatory in Washington. Because of the small size and faintness of these two objects (both are around magnitude 11), coupled with their nearness to the overwhelming brilliance of the Martian disk, Phobos and Demos are all but impossible to see through an amateur astronomer's telescope, even during a favorable opposition sequence of the planet. Interesting enough, the existence of the two Martian satellites had been predicted more than 150 years before their actual discovery, by Jonathan Swift in his epic work Gulliver's Travels. The orbits of both satellites are almost circular and lie almost directly on the plane of the planet's equator. Phobos which is about 17 miles long and circles Mars at an average distance of about 3,700 miles above the planet's surface revolves in the same direction and much faster than the planet rotates. To an observer on the surface of Mars the satellite, roughly one half the angular diameter of the Martian Sun, would appear to move from west to east in the sky and would not remain above the horizon for longer than three hours and ten minutes, during which time it would run through a major portion of its phase cycle. The night side of Phobos would be faintly illuminated by sunlight reflected from Mars, in a manner not unlike that of Earthshine appearing on the Moon, when it is seen from Earth, during its crescent phase. Moreover a suitably located observer on Mars would see Phobos making a 30 second transit, during an annular eclipse, across the disk of the Sun whose apparent diameter in the Martian sky would be about two thirds as large as it is seen from Earth. The planetesimal-like satellite's fifty mile wide penumbral shadow would bathe the observer in the slightly dimmed light of an already muted Martian Sun. Demos, which is about nine miles long orbits Mars in the same direction as Phobos in a period somewhat longer than one Martian day at a distance of about 12,500 miles from the planet's surface. Demos would appear starlike and too small for an observer on Mars to easily discern its angular shape with the naked eye. Both satellites, which seem to closely resemble typical asteroids are comparatively dark rocky objects made of material known to be common in the asteroid belt beyond Mars. Due to tidal forces Phobos and Demos both continually maintain one side toward Mars, thus they tumble once as they round the planet. Even though both bodies appear to be severely battered, a likely effect associated with the circumstances surrounding the event of their original break up, studies of their orbital dynamics indicate that no large impact has disrupted the tidal locking of either one for quite some time, thus lending credence to the idea that the phenomenon of drifting interplanetary debris represented a relatively brief although intense era early in the solar system's history, rather than a gradual clean-up of accretion residue by the planets over billions of years. It is also possible that Mars had captured other similar fragments early on when the major portion of these particles were sweeping by the planet. Some of these near-miss projectiles may very well have entered into short lived orbits around Mars which eventually decayed leaving these objects to their fate of plunging into the Martian surface as meteorites. Phobos and Demos have survived to this day perhaps only because they had entered the gravitational influence of Mars under more favorable circumstances and assumed the most stable orbits, over the planet's equator. If the volume of Phobos and Demos were reduced to ball shaped bodies the two would indeed be flying spherical mountains about 14 and 8 miles in diameter respectively. It is believed that these two irregular moons are merely captured fragments of a once major solar system planetary body.
Roughly every two years Mars appears as a favorite planetary object for observers to inspect with their telescopes. The best apparitions for viewing Mars, which are called perihelion oppositions, are the appearances which occur at 15 to 17 year intervals. The next such event will occur in late August of the year 2003. The scale of Mars and its distance during one of these near approaches can be visualized by placing a marble on a fence post and walking back to look at it from about 400 feet away. To all but the sharpest eye the marble would be virtually invisible at that distance but through a telescope at 300 power it would appear about the size of one's little fingernail held out at arm's length, subtending slightly greater than 25 arc seconds. One arc second can be compared to the thickness of a human hair seen from eight feet away.
Even though the current Martian opposition sequence does not provide us with the optimum viewing opportunity for telescopy, 1997 is an interesting year in terms of other events related to the Red Planet. The hype, in spite of disclaimers, continues to run high over supposed microscopic fossil life forms found in a potato sized rock allegedly from Mars that was recovered in Antarctica a few years ago. Also, two NASA spacecraft are currently in route to Mars to study that planet. One of the craft will attempt to make a landing on Mars, the first in more than twenty years to do so. It is hoped that these craft will not be lost as were their two predecessors, the American Mars Observer and the Russian Phobos probes. For the back yard astronomer Mars can be seen shining brilliantly as a ruddy star in the constellation Virgo during February and March. On March 17 the bright red planet will be at opposition when it will rise at sunset, be up all night, and set at sunrise. It is likely that interest in Mars during this opposition will take second place to the attraction of comet Hale-Bopp. Mysteriously enough, although, there has been, to this date, a strange deficiency of media attention to this great comet. Many have not even heard that there was a significant naked eye comet to be seen in the night skies presently. This is in conspicuous contrast to the degree of attention given to Halley's Comet in 1985-1986, Comet Shoemaker-Levy in 1996, and Comet Hayakutake in March of 1996. Even though Hale-Bopp was predicted early on to be the celestial light show of the century as far as comets go, there has been very little public information made available about this comet, except for a current flurry of Sci-Fi disaster features on TV involving asteroids and comets.
Nevertheless, in addition its own intrinsic interest, the planet Mars abides as a perennial witness to the awe, wonder, and mystery of crea tion. The Mars stands as a testament to the uniqueness, special design, and centrality of the Earth in the focus of the benevolent attentions of an omniscient, omnipresent, and omnipotent Creator.
1Copyright ã 1995 by J. Timothy Unruh, Back Yard Astronomers, P.O. Box 1034, Rocklin, California 95677-1034. Item No. 26041995JTU.