We continue the series of answers to subscribers’ questions:
Mars has attracted the attention of astronomers for a long time. The optimal conditions for observing Mars are formed during the great oppositions — i.e. moments when the Earth is exactly between Mars and the Sun while Mars is at perihelion, those. at the point of the orbit closest to the Sun.
Such moments happen every 16-17 years. In 1877, the Italian astronomer Giovanni Schiaparelli, observing Mars through a 15-centimeter refractor telescope, discovered on it a grid of thin lines, which he called channels. He also made a map of Mars and plotted about a hundred channels on it. Later, other astronomers confirmed the discovery of the channels.
Channel detection was received with great interest. There are many hypotheses about the origin of the mysterious lines. The main hypothesis was that the canals were man-made: it was assumed that this was either a network of highways or a complex of irrigation structures, but there were other versions, as some scientists believed that the canals were canyons or mountain ranges.
At the same time, astronomers were preparing for the next great confrontation in order to better see the strange lines. The best prepared was the American astronomer Percival Lowell, who at his own expense built an observatory in Arizona where the world’s largest refractor telescope with an aperture of 61 centimeters was installed. During the next great confrontation, Lowell was able to observe and map many of the Martian channels.
According to Lowell, the canals were about 100 kilometers wide and served to transport water from the polar caps of Mars to arid equatorial regions.
The idea of the existence of channels on Mars persisted until the late 1960s. In 1969, the Mariner 6 and Mariner 7 spacecraft transmitted photographs of the disk of Mars taken in relative proximity to it, and in 1971, the Mariner 9 spacecraft became the first artificial satellite of Mars and transmitted many images of its surface to Earth.
Much to my surprise and disappointment, no channels were found in the images. All further studies of Mars using space technology did not confirm the presence of channels on Mars. They are absent, including in the pictures taken by the Hubble telescope.
The question remains:
The current view of the channel problem is that the channels observed by astronomers in the late 19th and early 20th centuries were a combination of optical illusion and optical illusion caused by poor observing conditions and imperfect technology.
Indeed, even at the end of the 19th and the beginning of the 20th century, not all astronomers observed the channels, and over time, as telescopes improved, reports on the observed channels became less and less frequent.
First, all observations were made from the surface of the Earth, i.e. the rays of light entering the telescope lens passed through the thickness of the earth’s atmosphere and were distorted.
Astronomers actually observed the disk of the planet as if in a haze, like a haze over hot asphalt. The observation was reduced to a long sitting in front of the telescope lens, waiting for the moment when the image of the disk would somehow become clearer, and then quickly sketch what he saw from memory. Under such conditions, observation errors are quite possible, as well as wishful thinking.
Over time, observational technology improved, observatories began to be built high in the mountains to reduce the influence of the atmosphere, and methods appeared to minimize the effects of atmospheric visibility. And the channels began to disappear.
Nowadays, not a single professional optical telescope allows you to “see” the channels. However, many amateur astronomers using techniques similar to those used by Schiaparelli and Lowell sometimes report observing canals. It seems that the probability of observing channels is inversely proportional to the quality of the observing technique — the worse the telescope, the greater the chance of «seeing» the channels.
Another argument in favor of the fact that the channels never existed is that the channel maps compiled by different astronomers practically do not coincide with each other.
Well, of course, no one seriously considers the conspiracy theory that the channels used to be, but then the Martians, seeing the approach of the Earth’s spacecraft, «hid» them.