Starry Skies Above Santa Monica
April 11-18, 2000

Mirek Plavec
Emeritus Professor of Astronomy, 
UCLA

   Spring Sun and (a little bit tricky) Moon
   The Sun is now quite high (10 degrees) above the celestial equator, and so it passes overhead, at the local noon, above places with a latitude of + 10 degrees. This time, there are several fairly prominent candidates for this honor: San Jose, Costa Rica; Caracas, Venezuela; in Africa, Kankan in Guinea, and just a bit north of Adis Ababa, Ethiopia; in Asia, Cochin and Madurai at the southern tip of India, and the city that is so simply called Thanh Pho Ho Chi Min, and used to be known as Saigon.
   For us, the Sun will pass 24 degrees south of the zenith, but you may very well feel that the Sun is virtually overhead. On Sunday, April 15, the Sun will rise at 6:22 and set at 7:25 p.m.
   Now the Moon. I called it “a bit tricky,” so I must explain. On Thursday, April 12, the Moon will not rise at all! The Moon’s time table is by no means simple. It moves relatively fast eastward with respect to the Sun or stars, and on the average, it rises about 50 minutes later each subsequent night. It was Full on the night of April 7/8, and rose at 7:07 p.m. on Saturday, April 7. On Palm Sunday, April 8, it rose at 8:13 p.m. This is not 50 minutes later, but full 66 minutes later. Why? The Moon was traveling to the south-east, imitating the early October Sun; therefore its rising time intervals were longer than average. On Monday, April 9, the Moon rose at 9:18 p.m., on Tuesday at 10:22 p.m., and on Wednesday, April 11, at 11:23 p.m. Thus, about one hour later every night. But the next one-hour step brings the rising time to 0:22 a.m., which is not Thursday, April 12, but already early Friday, April 13!
   During all this time, the illuminated portion of the Moon’s disk, as seen by us, has been shrinking. The Last Quarter comes on Sunday, April 15, and by the middle of the following week, the Moon will be a fairly thin crescent, rising in the wee hours. 

   The Planets: A Feeble Show
   The two evening planets, Jupiter and Saturn, are still visible, but their show is rapidly coming to an end. You must search for them above the western horizon fairly soon after sunset. You can spot Jupiter already by about 8 p.m.; it is quite bright, but it will set before 11 p.m. Saturn, significantly fainter than Jupiter but still a first magnitude “star” lies to the west of Jupiter and will therefore disappear earlier, by 10 p.m. Disappearing with them from our starry sky is the prominent star cluster of the Pleiades, located to the north of Saturn, and the reddish star Aldebaran (“the Bull’s Eye”) below Jupiter.
   Mars is already quite bright, competing with the brightest stars, but rises deep in the south-east at midnight, and will hardly attract much attention. The same is true about Venus. Venus is very bright, but rises in the east as late as 5 a.m., when the eastern horizon already begins to brighten, announcing the coming Sun. 

   A First Lesson in Astrology
   The roots of our astrological tradition can most likely be traced to ancient Mesopotamia – present-day Iraq. The traditional name refers to “a country between rivers,” and the two rivers are the Euphrates and the Tigris. In the other ancient civilization based on a river, Egypt, the Nile was a well-behaving river. Its flooding was coming regularly, once per year, and supplied fertile mud for Egyptian agriculture. And when they discovered that, just at the right time before the floods, the bright star Sirius appeared for the first time in the morning before the Sun (an apparition which is called “the heliacal rising”), they had a reliable announcer of the floods.
   The two big rivers in Mesopotamia, however, were wild and unpredictable. They come from the mountains in Turkey, actually from the southern slopes of the Caucasus, and the rains and snows in that region vary wildly from year to year.
   When the inhabitants of Mesopotamia, perhaps stimulated by the success story of Egypt, searched for a celestial announcer of the floods, they realized that it must be a phenomenon much more complex than a simple appearance of one star. The five planets then known -– Mercury, Venus, Mars, Jupiter and Saturn –- offered quite an intriguing theater. They were in constant diverse motions, meeting and parting, shining bright as Mars will be this summer, and fading from the sky as Jupiter and Saturn are now. Those people had no idea what these bright objects in the sky were; however, since they seemed to be moving according to their own will, they were generally considered as gods, ruling above the people down here.
   If these planets were to be actors in a drama that was to create weather, they had to get definite roles. Jupiter is always very bright, when visible at all; it travels among the stars in a slow and majestic way, and so he got the role of a king, majestic, powerful, but essentially benevolent. Just the opposite character was Mercury: always being in a hurry, showing in the west after sunset for a few weeks, then switching to the morning sky for another short appearance. Thus Mercury became an unreliable character, good at one time and bad the next time.
   Venus is very lovely and beautiful, especially when it shines in the darkening western sky after sunset. Thus, although it had various names (Istar, Astarte, Afrodite, Venus), that planet was always considered to be a goddess of love – beautiful, although a bit moody (as it demonstrated recently, when it suddenly switched from the evening to the morning sky).
   Mars was a sneaky planet. Most of the time (like now) hardly conspicuous, it rather suddenly became quite prominent in the sky (as it will this summer). And Mars has a distinctly reddish color. Therefore, all the ancients agreed, Mars must be a very bad god, bringing fire, war, destruction. Poor Mars – and fire! It is actually a fairly cold planet, and the “fiery” color is due to its desert sands and a very thin atmosphere.
   OK, the show may begin: one devil – Mars; one shaky character - Mercury; two good ones - Jupiter and Venus… Wait a minute! More evil is needed to balance the scales! And so, Saturn was also assigned a negative role. About its beautiful rings no one knew, of course. Its light is a bit yellowish – let’s say, sickly yellowish. And you have the second bad guy!
   Thus, these superficial (and not too striking) properties of those mysterious moving lights up there above the Earth were employed to predict human fates…