The month of May is named after Maia, the Roman goddess of the earth. Even though the official Earth Day was at the end of April, May is really the month when we become more aware of the earth again here in the northern hemisphere. Our entire landscape will slowly transform itself as the earth awakens in response to more direct sunshine.
This will also be a great month to venture outside again to get reacquainted with the night sky. There are plenty of interesting highlights to enjoy and appreciate this month.
Four of the five brightest planets will become evening planets by the end of May. All four of them are also getting higher, brighter and closer to Earth. Jupiter will be the first; it reaches opposition on the 8th, followed by Saturn in June, Mars in July and finally greatest elongation for Venus in August. Mars will exhibit the most dramatic increase; it nearly doubles in brightness and gets one-third larger by the end of May. The annual Eta Aquarid meteor shower peaks May 6. None of the planets are really getting any closer this month, but the moon will pass close to Saturn and Mars early this month, close to Venus on the 17th, and close to Saturn again on the 31st.
When Jupiter reaches opposition on May 8, it will rise at sunset, reach its highest point in our sky at midnight and not set until sunrise. It is directly opposite the sun in our sky, similar to the full moon each month. It’s still in westward motion in Libra, as it has been since March 9. Opposition always marks the midpoint of a superior planet’s retrograde loop. Jupiter begins a normal, eastward motion through our sky again in early July.
Look for the great red spot this month if you can manage a view through a telescope. Jupiter is 10 times larger than the Earth, and this one spot can fit about two Earths into it. Jupiter rotates quickly, completing one rotation in just 10 hours. This generates the incredible turbulence we see on its surface.
The Juno mission, launched in August 2011, reached Jupiter on July 4, 2016. It’s since taken many astonishing images as it continues to dive just 2,700 miles above its cloud tops every 53 days. The planet’s south pole turned out to exhibit far more turbulence than expected. It has five giant cyclones surrounded by hundreds of whitish swirls against a bluish surface, looking more like an impressionistic painting or Van Gogh’s “Starry Night” than the normal surface of a giant gas planet.
The north pole is equally astounding, displaying eight evenly sized cyclones circling around a single 2,500 mile-wide cyclone. By contrast, Saturn has one cyclone at each of its poles, but the one at the north pole is a giant hexagon with each side measuring 8,600 miles. Both Jupiter and Saturn have lightning, and northern and southern lights near their poles. But their auroras aren’t in sync as on Earth. The ones on Jupiter are brightest in X-rays. Jupiter’s magnetic field is 20,000 times stronger than Earth’s, so it makes sense that its aurora is also more powerful and intense.
Saturn starts the month rising around midnight, but it will rise two hours earlier by the end of May, approaching its own opposition on June 24. The ringed planet falls a little farther behind Mars this month in Sagittarius but they are still fairly close. Watch as a nearly full moon passes near Saturn on the 4th and 5th, then close to Mars on the 6th, the same day the Eta Aquarids will peak.
Mars will rise around 1:30 a.m. starting the month and around midnight by the end of the month. But Mars will exhibit the greatest size and brightness increase of any of the planets due to its unique orbit. We are catching up with the red planet to create this effect, as we are with Jupiter and Saturn, but Mars is much closer than the other two planets. Venus is getting brighter and higher in our sky because it’s catching up with us. Mars will get to a brilliant minus 1.2 magnitude, or about four times brighter than nearby Saturn by the end of the month. Mars will be at its best opposition in 15 years by the end of July, at just 35.8 million miles from Earth, or only 1.2 million miles farther than its closest opposition in August 2003 in nearly 60,000 years.
Look for tiny, sand-grain-sized pieces of Halley’s Comet to disintegrate high in our atmosphere during the first week of May, peaking on Sunday morning, May 6. The nearly last-quarter moon will rise around 1 a.m. that day to spoil the show after that, but it will be well worth catching what you can All these tiny pieces of the comet will appear to radiate out of the water jug asterism in Aquarius that night. That’s a summer constellation, so it doesn’t even rise until a few hours before dawn, meaning you’ll see fewer meteors than if the radiant would have been higher in the sky.
May 2: Venus and Aldebaran in Taurus, 6 degrees apart, set together in the west around 9 p.m.
May 4: The moon is near Saturn.
May 5: On this day in 1961 Alan Shepard became the first American in space aboard Freedom 7.
May 6: The Eta Aquarid Meteor Shower peaks this morning. The moon is near Mars.
May 7: Third-quarter moon is at 10:10 p.m.
May 9: Jupiter reaches opposition.
May 10: Cecelia Payne-Gaposchkin, British-born American astronomer, was born on this day in 1900. She helped decode the complicated spectra of starlight along with the famous “Harvard Computers.” She wrote one of the most brilliant papers in astronomy as she finally determined the true composition of all stars. She was also an excellent musician.
May 14: Our first space station, Skylab, was launched in 1973.
May 15: New moon is at 7:49 a.m.
May 17: A thin waxing crescent moon with earthshine joins Venus as they set just 6 degrees apart.
May 21: First-quarter moon is at 11:50 p.m. It will be less than one degree from Regulus in Leo, about where the sun was last Aug. 21 during the total solar eclipse.
May 25: Spica and the waxing gibbous moon will cross the sky in tandem separated by 6 degrees.
May 28: On this day in 1959, Able and Baker became the first primates in space that returned to Earth safely.
May 29: In 1919, Arthur Eddington led a total solar eclipse expedition to Africa that proved Einstein’s general relativity correct by measuring the exact displacement of star behind the eclipsed sun. Full moon is at 10:21 a.m. This is the Planting, Milk or Flower Moon.
May 31: The moon and Saturn rise just two degrees apart around 9 p.m.
Bernie Reim of Wells is co-director of the Astronomical Society of Northern New England