The month of May is named for Maia, the Roman goddess of the earth. We are halfway into spring already, but this part of the northern hemisphere is just beginning to awaken as myriad shades of green spread across and infuse our landscape with new life and hope. Buds are opening and tender young leaves are springing to life. Some of the birds have returned, and the spring peepers are contributing to the audible soundtrack in the early evenings as the whole chorus of nature sings again. It is truly a natural symphony of the earth across the visible and audible spectrum, revealing the irrepressible nature of life in its many forms.

The skies are also undergoing a continuous and predictable transformation as we lose the Winter Hexagon in the west even as the Summer Triangle rises in the east. It’s a great time to get outside again as the weather warms, allowing us to better enjoy the many celestial highlights visible this month.

Mars is finally getting some company in the evening sky, as Jupiter is rising at about the same time as Mars is setting, around 10 p.m. Saturn also pushes across the midnight rising threshold early this month, even as Venus continues to rise in the morning twilight an hour before the sun. Mercury will join the evening planets toward the end of May. The moon will pass right through the Beehive cluster in Cancer and form several nice conjunctions with planets. Ceres and another asteroid, Pallas, reach opposition this month, and a faint comet passes through Scorpius. Beyond that the main highlight this month will be the indirect return of Halley’s Comet in the form of the Eta Aquarid Meteor Shower, which will be favorable this year because the moon will not interfere.

Mars recently passed directly between the Hyades and Pleiades open star clusters in Taurus and is now rapidly heading into Gemini. Look for Mars to form the third horn of Taurus the Bull in early May, when it will appear directly between the two stars that normally make up the two horns. On May 7, a slender waxing crescent moon will slide by the red planet within a few degrees. Keep watching as Mars will have a close encounter with a large open star cluster – M35 – at the feet of Gemini the twins on the 19th. Mars continues to fade as we leave it farther behind in our orbits, but you can still tell that it is distinctly orange and not white.

Jupiter rises about four minutes earlier each evening, beginning the month rising around 11 p.m. The king of the planets is already in retrograde or westward motion back toward Antares in Scorpius and will reach opposition on June 10, when it will rise right at sunset. It continues to brighten a little each evening as we are catching up with this huge planet in our sky, which is 10 times our size, but still 10 times smaller than the sun. Remember that Juno is still orbiting this planet in highly elliptical orbits that plunges it down to just a few thousand miles above its turbulent poles every 53 days.  The spacecraft continues to take remarkable pictures of this planet, which, with its great and colorful swirls of dense clouds, looks more like Van Gogh’s “Starry Night” than what we would expect from a planetary surface.

Saturn starts this month rising just after midnight and ends up rising around 10 p.m., approaching its own opposition in early July, a month after Jupiter will be at its best. The ringed planet will also brighten noticeably this month, but it will still be three magnitudes, or 15 times fainter, than its cousin, Jupiter.  You can see five of its brightest moons in a small telescope, but you can see all four of Jupiter’s brightest Galilean moons with just a pair of binoculars. That is mainly because Saturn is twice as far away at nearly 1 billion miles, or more than an hour at the speed of light.

Venus is way ahead of the earth now and rises only an hour before sunrise in the morning twilight. It is at its faintest for the year, even though it is nearly fully illuminated by the sun, approaching superior conjunction. Our sister planet is still more than three times brighter than Jupiter.

Mercury will put in a brief appearance low in the morning sky near Venus early this month and then again low in the evening sky near Mars on the last few days this month. It will put on a better show next month.

Watch carefully as a waxing crescent moon will pass right in front of the Beehive Cluster (M44) on the evening of Friday, May 10. Try to photograph this fairly rare event and use binoculars or a small telescope to better see it. The moon will cover about a dozen stars in the Beehive between 10 and 11 p.m.

The asteroid Ceres will reach opposition at the end of this month in Scorpius, not far from Jupiter. At 600 miles across, or about the size of Texas, Ceres was the first asteroid discovered, in 1801, and is the only asteroid to be classified as a dwarf planet. Ceres is layered, with a dense rocky core at its center, an icy mantle, and an icy crust at its surface. It will reach 7th magnitude, just out of visible reach. Pallas will reach opposition in Coma Berenices in early May, reaching 8.3 magnitude. It is about half the size of Ceres.

The conditions are favorable for the return of tiny, sand-grain-sized pieces of Halley’s Comet this month on Monday morning, May 6. Radiating from a point in the sky in the water jug asterism in Aquarius, you can expect about 20 meteors per hour. If you lived in the southern hemisphere, you could see around 60 per hour. The best meteor shower I ever saw was the Leonid meteor shower on Nov. 18, 2001. We had just built our observatory in Kennebunk, and we saw nearly 1,000 meteors per hour over the course of nearly three hours that memorable night, right until twilight started washing them out. That averaged out to one meteor every four seconds. There was no lull longer than 10 seconds, and I saw as many as seven in one single second, much better than fireworks. We also saw many brilliant bolides that lit up the whole sky. The constant rain of meteors was so intense that I could get a sense of the earth’s 18.6 mile-per-second motion through space for the only time. The only event in astronomy that could top that would be a total solar eclipse – and we just happen to have one that will cross right over Maine in less than five years, on April 8, 2024.


May 2: The waning crescent moon passes near Venus this morning.

May 3: The moon passes near Mercury this morning.

May 4: New moon is at 6:46 p.m.

May 5: In 1961, Alan Shepard, aboard Freedom 7, became the first American in space.

May 6: The Eta Aquarid meteor shower peaks this morning. The night before and after should also produce many meteors.

May 7: The moon passes just south of Mars this evening.

May 10: The moon will pass right in front of dozens of stars in the Beehive cluster this evening.

In 1900, Cecilia Payne-Gaposchkin was born in England. She became an American astronomer who helped decode the complicated spectra of starlight, along with the famous “Harvard Computers” – women astronomers who developed the spectral classification system for stars. She wrote a brilliant paper determining the true composition of stars, and was also a good musician.

May 11: First-quarter moon is at 9:12 p.m.

May 14: Our first space station, Skylab, was launched in 1973.

May 18: Full moon is at 5:11 p.m. This is also known as the Milk, Planting or Flower Moon.

May 20: The moon passes just north of Jupiter this morning.

May 21: Mercury is in superior conjunction with the sun this morning.

May 22: The moon passes just south of Saturn this morning.

May 26: Last-quarter moon is at 12:34 p.m.

May 28: Ceres is at opposition this evening.

May 29: In 1959, Able and Baker were the first primates in space and returned to Earth safely.

Bernie Reim of Wells is co-director of the Astronomical Society of Northern New England.

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