Popular Notions of Solar System Hit at Observatory Open House

Speaking before an overflow crowd at the Harvard Observatory's open house last night, William Liller, new chairman of the Department of Astronomy, shattered some of the more romantic notions concerning the solar system.

The fabled Martian canals have never been photographed or even reliably sighted, Liller pointed out. He even questioned their existence on the basis of his own and other recent observations.

Future venturers to Mars and Venus will encounter great survival difficulties, including a temperature on Venus "well over the boiling point of water." Liller noted that, although certain parts of Mars sometimes reach a balmy 85 degrees Fahrenheit during the day, the prospective explorers would have a rough time surviving the 156-degree-below-zero nights.

He went on to cite advances made in his own field of spectrophotometry and showed slides of the spectrum of light from Mars, which seem to indicate there is no oxygen on that planet. Mars' famed polar ice caps, he noted, are probably no more than frost "a few millimeters thick."

Colder Than Pluto

Liller also dwelled on some of the oddities and paradoxes of planets, in addition to debunking popular conceptions. Mercury, the smallest planet, has both the highest and lowest temperature in the solar system. While temperatures on the side of Mercury that always faces the sun rise to 800 degrees Fahrenheit, the dark side (only 50 degrees above absolute zero) is colder than Pluto, the furthermost planet from the sun.

Continuing his study of astronomical phenomena. Liller used the density of the planet Saturn, estimated at .72 the density of water. Astronomers have calculated, however, that even if the entire planet were made up only of hydrogen, the lightest element, gravitational attraction of atoms would bind them together so tightly that their density would be far greater than .72.

In his final pot-shot at the romanticists, Liller discounted the popular 1910 reports of the size and brightness of Halley's comet. He remarked that at least two comets sighted within the last ten years and hardly noticed by the public were probably as bright as or brighter than Halley's comet.