THE PLANETS IN SEPTEMBER

Press, Volume LXXXVIII, Issue 26824, 1 September 1952, Page 2

THE PLANETS IN SEPTEMBER

(Written for "The. Press by K.W. ROTH) The visibility conditions of Venus, the evening star, improve very considerably during September. By the end of this month Venus will have become brilliant enough to catch the eye of even the casual observer. Its time of setting changes steadily from about 7.30 p.m. at the beginning, to 9 p.m. at the end of September. Very noticeable is the shifting of the point where Venus sets on the horizon. This point moves about 20 degrees southward during the month. „ The red planet Mars is moving right across the beautiful constellation Scorpius. It passes its rival in colour, Antares, the main star in Scorpius, on September 11, at the apparent distance of five moon discs. Although these two objects look superficially alike, they are very different in physical nature. Mars, which appears the brighter of the two, is a planet only one-eighth the size of the earth. It is not selfluminous, but only reflects incident sunlight. It is a fairly cold world, decidedly cooler than the earth. Antares, on the other hand, is a giant fixed star, self luminous like our sun. Though considerably cooler than the sun, it has nevertheless a surface temperature of some 4000. degrees Fahrenheit, incomparably hotter than the surface of Mars. The respective densities are also very different Mars is not unlike the earth, whereas Antares consists mostly of very ratified gas, much more tenuous and much larger than is the sun. Mars sets about 1.30, 1.15 and 1.5 a.m. on September 1, 16 arid 30. Jupiter, the largest planet of the solar family, is the brightest star of the late night sky. It rises in the region roughly opposite where Mars is about to set, about 0.10 a.m., 11.10 p.m. and 10.10 p.m., respectively. Saturn is about to disappear behind the sun’s rays and is visible only during the first half of the month. It sets at 8.50 p.m. on September 1 and’ at 8 p.m. on September 16.