OBJECTS IN THE SKY

 

“Between 1914 and 1916, Gustav Holst composed his orchestral suite “The Planets”. He had been introduced to astrology by Clifford Bax while on holiday in Majorca in 1913 and held astrology to be his “pet vice”. His work “The Planets” represented the seven known planets of the time. These were Mercury, Venus, Mars, Jupiter, Saturn, Neptune and Uranus. Earth, which had no astrological significance, was excluded, as was Pluto, which had not yet been discovered.

The sixth movement of “The Planets” was “Saturn”, subtitled “The Bringer of Old Age”.
In the Roman pantheon, Saturn not only brought old age among humankind, but was also the god of time, seasons, and agriculture. He was held to be an absolute god of a golden age of plenty, wealth and pleasure before time and hence before the founding of the Roman Empire. The Saturnalia was a festival held on December 17 of the Julian calendar, attended by merrymaking and wild revelry with some milder nuances. The festival was later extended past the Winter Solstice, after which it included feasting, gifts to the poor, and the decoration of trees.

Saturn is one of the four gas giants, the sixth planet from the sun at a distance of 888,200,000 miles. It differs from the terrestrial (Earth-like) planets in that it has no solid surface. Saturn has a diameter of about 72,400 miles, or about nine times that of Earth. Saturn takes about 29 Earth years to orbit the Sun. Ignoring the retrograde motion of Saturn, this means that each year Saturn lags by about two weeks its position in the sky the previous year.

Unlike Jupiter, with its colored bands and Red Spot, Saturn has a non-descript orange-tan surface appearance. All of the gas giants have rings, but Saturn has the most extensive ring system. Under low magnification, one can see three rings. In contrast, images from the Hubble Space Telescope reveal about 30 rings. These rings are generally considered one or more moons of Saturn (or other objects, by some) whose orbits brought them inside the Roche limit of about 90,000 miles for Saturn. These objects became unstable because of tidal forces and broke up, forming small chunks and particles, often of ice with a coating of dust. These reflect light from the Sun and appear as Saturn’s rings.

Traveling through the upper atmosphere of Saturn, one passes through layers of ammonia crystals and hydrogen, followed by liquid hydrogen, a rain of liquid helium deep inside the planet, metallic hydrogen and helium, ices, and finally a relatively small rocky core. As gaseous helium condenses into rain-like droplets of liquid, energy is released. This energy is evidence that Saturn is still in the process of formation as a planet. Interestingly, Saturn has a low density of about two-thirds that of water. This means that Saturn would actually float in a very large bathtub of water.

During the period when Holst wrote “The Planets”, Saturn could be seen in the evening over England between July and December 1914 and then again, from July 1915 to February 1916. During the second week in September of 2020, at about 9:00 PM in Wisconsin, Saturn will appear in the south at an altitude of 23.1°, about a quarter of the way above the horizon toward the azimuth (overhead). Facing south, it will be about a hand width held at arm’s length to the left (east) of brighter Jupiter. Find a spot with a clear view of the south and bring a telescope or good binoculars.

Holst considered “Saturn” to be his favorite movement in “The Planets”. ”