Jupiter is on its way out of the evening sky. The big planet will be in conjunction with the sun on June 24. Most observers will see it heading into the sunset this month. Then for June and July, it will be too close to the sun to see until it emerges into the morning sky. As May progresses, Jupiter gets slowly closer to the horizon. You can also see it moving out of the easternmost reaches of Taurus and toward the feet of Gemini. Pollux and Castor are nicely placed above Jupiter in the west. They are the head stars of Gemini. The moon’s between Jupiter and those stars on the 1st.
Higher up on the western side of the sky at dusk is Mars. At the start of March, it’s approaching the Beehive, also known as M44 and Praesepe the manger. The moon is almost at first quarter when it passes Mars and the Beehive on the 3rd. On the 4th and 5th, the red planet passes through the cluster. This will be a splendid sight in binoculars. After passing through Cancer, it’s on to Leo. Mars won’t make it all the way to the bright star Regulus this month. That’ll be on June 16th and 17th.
The moon’s just past full when it passes Regulus on the 5th. On the 8th, a waxing gibbous lunar disk passes in front of Zavijava. If you’re in the far southeast Pacific Ocean or on the western hemisphere part of Antarctica, you may see the occultation. Although Zavijava is called Beta Virginis, implying that it’s the second brightest star in Virgo, it’s actually the fifth brightest. It’s 36 light years away. The name Zavijava comes from Arabic for the “corner of the barking dog”.
Virgo is where to find Vesta this month. The asteroid is at opposition on the 2nd, but all month is a good time to look with binoculars or a telescope. The asteroid is in the virgin’s feet.
The moon passes Spica on the 9th and 10th. The moon’s full when it’s in Libra on the 12th. The southern part of South America gets an occultation of Antares on the 14th. So do ocean regions on either side of and near the continent. We have a last quarter moon in Capricornus on the 20th.
Venus and Saturn are close together in the morning when May begins. Wait long enough and you may spot Mercury at the beginning of the month. The messenger planet is much easier to see from the southern hemisphere though. Northern observers who can see Mercury will see it sliding northward along the horizon morning to morning in the dawn’s glow.
A waning crescent moon approaches Saturn on the 22nd. The moon’s closest to Venus on the 24th. Look any of these mornings around that time for the spectacle of the moon and these two planets.
Venus and Saturn are separating while Mercury heads to superior conjuction on the 30th. Mercury is at perihelion on the 31st at 0.31 astronomical units from the sun.
The Eta-Aquariid meteor shower peaks on the 5th and 6th. This is a good shower for southern hemisphere observers, who may see up to 50 meteors per hour. They are fast and the streaks they leave often glow for several seconds. The moon sets before the radiant, where the meteors appear to come from, rises. These meteors come from dust left behind by Comet Halley.
The moon’s circumstances this month:
Northern lunistice on the 1st at 28.6°, over the equator going south on the 8th, southern lunistice on the 15th at 28.5°, northbound over the equator on the 22nd, and northern lunistice again on the 28th at 28.4°.
First quarter on the 4th, full on the 12th, last quarter on the 20th, and new on the 27th.
Apogee on the 11th at 406,300 km. Perigee on the 26th at 359,000 km.
Mars has its northern solstice on the 29th at 23:15 Universal Time. This is the same solstice Earth has in June. So the northern hemisphere of Mars is tilted sunward. But since Mars has a more elliptical orbit than Earth, the energy being received from the sun is a lot less now. Mars is farther from the sun during its northern summer and southern winter. The red planet’s coldest weather is at this time of the Martian year.
