THE PLANETS IN SEPTEMBER

Press, Volume XC, Issue 27443, 1 September 1954, Page 9

THE PLANETS IN SEPTEMBER

[Written for “The Press” by K. W. ROTH]

Mercury is low in the west after nightfall. The end of this month and the beginning of October is the best period of this year to find this elusive planet It sets 40 minutes after the sun on September 1, 80 minutes after the sun on September 16, and over two hours later than the sun at the end of this month. On September 23 Mercury passes 0.6 degrees north of Spica, the bright main star in the constellation Spica that is just being passed by Venus.

Venus is a glorious evening star now, unmistakably the brightest star in the sky, which nobody can fail to notice. It sets at 10.1 p.m. on September 1, at 10.32 p.m. on September 16 and also on September 30. On September 16 Venus passes 6 degrees above Saturn. Through a telescope Venus now appears crescent shaped; its phase decreases, but its diameter increases so that as a total effect the illuminated area still increases in spite of the waning of the crescent. No definite surface details can be seen of Venus because this planet is permanently shrouded by dense clouds. The moon passes one degree below Venus on September 30.

The planet Saturn sets about 15 degrees north of west at 10.46 p.m., 9.53 p.m., and 9 p.m., respectively. As long as it is sufficiently high above the horizon, it is still a rewarding object for telescopic observation. Mars increases its distance from 58,000,000 miles to 72,500,000 miles, and correspondingly diminishes in brightness. At first it is still as bright as Canopus, which is the second brightet of all fixed stars and at present low in the south; at the end of the month Mars is only about as bright as Alpha Centauri, the brighter of the pointer stars.. During the last month the appearance of Mars as . seen through a telescope has noticeably changed, from that of a fully illuminated disc with polar ice clearly visible and a few vague dark spots on the surface, to a three-quarter moon shape with hardly any details discernible. The colour has also changed from a bright orange to a darker tone.

Mars passes the north meridian at 8.2 p.m., 7.32 p.m., and 7.10 p.m. respectively, on September 1, 16 and 30. Jupiter is now a morning star. It rises at 4.52 a.m. on September 1, 4.03 a.m. on September 16, and at 3.16 a.m. on September 30. about 30 degrees north of due east. On September 21 the moon passes one degree above Jupiter.