May 28, 1999
5. Earth is pulling away from Mars at a rapid pace, leaving the dimmer and smaller disk of the red planet behind. Mars is still a fine sight, though, and offers the best planetary view once the evening stars, Venus and Mercury, have set. Mars will be keeping company this month with Spica, the brilliant star of the constellation Virgo.
6. The moon closes out its cycle of phases at 11:20 this evening, although it won't rise above the eastern horizon until about three hours later. The moon will be the most interesting object in the relatively bare field near Aquarius for a few hours until Jupiter and Saturn rise closer to sunrise.
9. Monks of ancient Britain were no strangers to turmoil. The coastal town of Canterbury had been ravaged by Danish raids through the 10th and 11th centuries; the infamous political murder of Thomas ö Becket had taken place there in 1170. So, we can believe that when they recorded a cataclysm on the moon, they weren't exaggerating. The monks probably saw the aftermath of a meteor impacting the lunar surface just beyond the Earth-facing horizon and recorded this stunning event on June 18, 1178.
11. In case you hadn't noticed, Venus has been awesomely bright and beautiful in the western twilight skies. Today marks our sister planet's greatest angular distance from the sun, which provides the longest time lag possible between sunset and Venus-set. The background stars of Cancer must struggle to compete with this gorgeous planet, and over the next few nights, they almost pull it off. Venus is grazing the lovely star cluster Praesepe, whose Greek name means "beehive." Judge for yourself whether it is aptly named. Praesepe is a good binocular object.
13. The moon is at new phase at 2:03 this afternoon but in no danger of passing directly in front of the sun. We are well out of the season for possible eclipses, and, in fact, the moon is nearly five degrees south of the sun's position today.
15. A very young moon stands nearly between Mercury and Venus this evening in the hour between sunset and full twilight; this should be approximately between 9 and 10 p.m. for Kansas.
16. Venus and the moon will be at their closest angular distance this evening at around 10, separated by approximately four lunar diameters. Mars is already above the southern horizon by this hour of the evening, still nestled close to Spica. This might be a good opportunity to review directions to Spica and another brilliant summer star, Arcturus. Look first to locate the Big Dipper; follow the arc of the dipper handle to Arcturus. Keep following that curving arc; it will lead you to Spica and, this month, Mars.
18. The sun doesn't set until nearly 9 these midsummer nights, but there's so much to admire in the evening sky that no one should begrudge the wait. Mercury is rarely as favorably positioned as it is this month; this elusive planet will be in Gemini, well above the west-northwestern horizon for at least an hour after sunset. Venus is further from the sun, above the west point on the horizon; further along the solar system plane is the zodiac constellation Leo the lion.
20. The moon arrives at its first quadrature at 1:13 this afternoon, 90 degrees from the sun's position. As it turns out, that's pretty close to local noon in most parts of Kansas and quite close to the hour when the first quarter moon peeps above the eastern horizon. The moon isn't hard to find in the daylight sky, although its stellar neighbors from the zodiac constellations Leo and Virgo won't be visible until after sunset.
21. The summer solstice occurs at 2:49 this afternoon, marking the moment when the sun reaches its most northerly position for the year. The sun is highest today in the northern hemisphere, the day is longest and the night painfully short (for astronomers, at least) † so why is this the start of summer? Our ancestors in the British Isles knew differently, and perhaps better when they called this "Midsummer Day."
22. What a great combination of beautiful objects. The moon and Mars will stage a not-so-close encounter near 3 p.m. today, visible in time zones to our east. Even for mid-American observers, though, this pairing is worth a look when Mars and the waxing moon form a luminous trio with the bright star of Virgo, lovely Spica.
25. Observatories are loosely defined by astronomers as places where astronomers work. More than one observatory is spread around several physical sites. Take the United States Naval Observatory, for example; headquartered in the nation's capitol, the observatory has outposts in Flagstaff, Ariz., and Chile. On June 22, 1978, observatory astronomers James Christy and Robert Harrington Christy studied photographs of our most distant planet and realized that part of the image included a small moon. More recent studies have found that Pluto and its small moon, Charon, are locked face to face in an orbital dance that repeats every 150 hours.
28. The sun is nearly as far north as it can be during the whole year, so it stands to reason that the full moon, opposite the sun's position on the globe of the sky, is pretty far south tonight. The moon, full at 4:37 this afternoon, will skim the top of the teapot shape of the constellation Sagittarius later this evening.
30. Although our active geology and atmosphere work continuously to erode the evidence, Earth is no stranger to cataclysmic impact. Witness the awesome collision between a wandering chunk of solar system and the Tunguska River region of Siberia on this date in 1908. At about 7:40 a.m., a small comet or asteroid skidded obliquely into the atmosphere, exploding with a force of many megatons above the largely (and fortunately) unpopulated region. Amid half a million obliterated acres, there was little evidence to recover, so the mystery of this projectile will never be completely resolved.