The month of May is named for Maia, the Roman goddess of the fields and plants. Maia was said to be the daughter of Atlas, whose seven daughters are represented by the Pleiades, and the mother of Mercury. In medieval times, people went “a-Maying” on the first day of the month gathering flowers in celebration of spring and the rebirth of life.

Focus on the planets

May brings the finest grouping of the five naked-eye planets to occur in the past 20 years. There is little point in discussing them separately for they are all visible together, at least early in the month. A thumbnail sketch of the pertinent region of the sky, low in the west-northwest, for the start, middle and end of the month will tell you what to expect. Be sure to start your observations early in the month as Mercury will be disappearing about mid-May.

About three-quarters of an hour after sunset on May 5, the three middle planets form a tight triangle in the west with Mars at the apex and Saturn and Venus acting as the left and right base points respectively. Mercury is to the lower right of Venus with Aldebaran directly to its left. Jupiter is well up on the horizon to the upper left of the triangle.

By May 14, the triangle will break up. The center point now is brilliant Venus being brushed by a thin crescent moon. In an irregular line descending from Venus is Mars, then Saturn, and finally Mercury, which still should be just visible above the horizon. Jupiter remains high to the upper left of Venus.

The show is about over by month’s end. May 31 finds only Jupiter and Venus close together and unmistakable for anything else. The two prominent stars above them are Castor and Pollux of Gemini. Mars still glows dimly to the lower right of Venus but Saturn and Mercury are gone.

Our celestial neighborhood

Recent evidence indicates that a “black hole” may exist at the center of our Milky Way galaxy. Of all the strange denizens of the universe, black holes certainly are among the strangest. Astronomers theorize that black holes form when stars 10 to 30 times the size of our sun collapse to an object about 2 miles in radius. If the Earth could undergo such a collapse, its entire mass would be contained in a ball less than four-tenths of an inch in radius!

The gravity of such an incredibly dense material would be so powerful that not even light photons would escape, hence the name “black hole.”

Black holes are detected when matter flows into their gravitational grip and high-energy X-rays are emitted. Black holes, ranging in size from an atom to galaxy-gobbling monsters millions of miles in diameter, may drift through the universe. Dr. Neil Comins, astronomy professor at the University of Maine, speculates in his book “What If The Moon Didn’t Exist?” as to what might happen if the Earth should encounter a black hole.

May events

1 Sunrise, 5:26 a.m.; sunset, 7:40 p.m. This is May Day or Beltane, a cross-quarter day marking the midpoint between the spring equinox and the summer solstice.

4 Moon in last quarter, 3:17 a.m.

5 Check the planets for the best celestial show in years.

7 Moon at apogee, or farthest distance from the Earth, tonight.

10 Venus is less than one-third of a degree north of Mars.

12 New moon, 6:46 a.m.

14 The sun enters Taurus on the ecliptic. Time to check out the planets again.

19 Whitsun or Whit Sunday marking the seventh Sunday after Easter. Moon in first quarter, 3:42 p.m.

21 The sun enters the astrological sign of Gemini but astronomically still is in Taurus.

23 Moon at perigee, or closest approach to the Earth, today.

26 Full moon, 7:51 a.m. The full moon of May is called the Planting Moon or Milk Moon.

31 Sunrise, 4:53 a.m.; sunset, 8:13 p.m. Be sure to take one final look at the best planetary display until 2020.

Clair Wood taught physics and chemistry for more than a decade at Eastern Maine Technical College in Bangor.