Sky & Telescope April 1988 [antikvár]

focal pointMartian Canals: Is Lowell Vindicated?I'M AMUSED, and at times angered, atthe way some people berate Percival Lowell for his sightings of "canals" on Mars. Books and articles remind us, almost ad nauseam, that Lowell's two chief antagonists, E. E. Barnard and E. M. Antoniadi, "never saw a canal." If so, why did they draw them? And I'm talking narrow canals too.One such drawing by Barnard appears on page 151 of H. A. Howe's Elements of Descriptive Astronomy; it depicts three short, narrow canals. Barnard made this observation on August 19, 1892 two years before Lowell began work at his observatory in Flagstaff, Arizona! Also, Sky Telescope ran a Mars drawing by Antoniadi on page 266 of its June, 1954, issue. It's complete with canals and "oases." And these observers didn't see canals? They certainly drew them.Antoniadi was right, however, in his interpretation of these linear features: he believed they were simply the merging of unresolved strings of isolated surface features. But he also stated that Mercury's atmosphere is more extensive than Mars' and is cloudier to boot. His drawings of Mercury are far more erroneous than Lowell's of Mars. Lowell said that Mercury had no atmosphere and was "the bleached bones of a world." Antoniadi was wrong about Mercury and Lowell was right.Lowell "turned off" many astronomers with his theories of an advanced civilization on Mars, but he "turned on" the young to choose astronomy or related sciences as a career. I suspect romanticism is the initial spark that starts the fires of curiosity burning.In 1892 Barnard viewed craters on Mars with the 36-inch refractor at Lick. John Mellish also observed them with Yerkes' 40-inch refractor in 1916. Yet neither of these skilled observers formally published their results. Had they done so, would the desire to explore Mars have come about? I doubt it.Mars would have been considered nothing but a larger version of our Moon. Consequently, interest in that planet would have died off quietly as it almost did in 1965 when Mariner 4 relayed images to Earth of a world spattered with craters. Astronomers were quick to follow with sweeping negative conclusions aboutlife on Mars, even though they had glimpsed less than 1 percent of the planet's surface close up.We should realize that the impetus to study Mars came from the curious theories of a romantic who went against the grain and never compromised with a critic. Ask a few astronomers who they associate first with Mars, and the majority will reply, "Percival Lowell."Now we know what the surface of Mars looks like. Yet visual observers continue to draw canals on the planet. I've been looking at Mars since 1954, but the only night I viewed canals like those sketched by Lowell or G. V. Schiaparelli was June 9, 1967. The sky was so thick with haze that no stars fainter than 2nd magnitude were visible, even near the zenith. Mars, al magnitude -0.4, was low in Virgo and looked no brighter than 3rd magnitude.With me was William H. McHugh, and it was through his optically excellent 8-inch f/9 reflector that we made our observations. We were using 250x to look at a disk only 12 arc seconds in diameter. After several moments of observing I asked McHugh, "Do you see what I see?" He said, "There are lines all over the place." We watched in amazement. The seeing was perfect no ripples, no undulations. The thick haze offered poor transparency but excellent seeing. We also called my wife, Irene, lo look through the telescope. She saw them too, without any coaching from us.Two canals stretched clearly from Sa-baeus Sinus and Meridiani Sinus to the northern deserts, where they faded. A most interesting canal was Deuteronilus-Protonilus originating in Niliacus La-cus which ran both east and west until I lost sight of it near the limb we counted at least six oases on this one, strung out like beads on a string!We needed no imagination to see these markings, for they were as prominent as the festoons that cut into Jupiter's equatorial zone. Until that night, if anyone had said that we could see canals with an 8-inch telescope when Mars was only 12 arc seconds in diameter, I would have said, "You're crazy."Recently 1 examined two sets of Mars photographs taken in 1971 through a 7-inch Questar. Although the same film had been used for both sets (H & W VTE), one roll was push-processed and then printed on high-contrast paper. The difference in detail is outstanding the high-contrast prints have far more detail, and there's no denying they contain some "spurious" features as well.Perhaps, and I say perhaps, the finer details on the high-contrast prints have, in the processing, "bled" into adjacent features. Could this effect be responsible for the Martian canals we see in certain photographs? If so, little wonder Lowell pointed to his photos as "proof" of his visual findings.Experts in photographic chemistry might comment on this possibility. In the meantime, to echo Ivan Dryer's fitting remark in the June issue, page 605: "If they're not there, how come they'reRODGER GORDONGordon, a former Jupiter recorder for the Association of Lunar and Planetary Observers, is a member of the Lehigh Valley Amateur Astronomical Society and a prolific author.