Wednesday, December 4, 2013
By BERNIE REIM
The month of May is named for the Greek goddess Maia, who was identified with the Roman goddess of fertility. As New England will continue its slow transformation into spring, so the skies above continue to reveal their new constellations, not seen since last year at this time. The famous Winter Hexagon continues to sink inexorably lower into our western sky even as the equally famous Summer Triangle is now beginning to rise over our eastern horizon.
Even though the days are getting longer, there is still plenty of night time to see and become aware of a few more of the wonders always present above us.
There are many interesting highlights this month, including a trio of bright planets in our evening sky, an annular solar eclipse over Australia, another partial penumbral eclipse of the moon and even another meteor shower, the Eta Aquarids.
Brilliant Venus has now reappeared in our evening sky, setting about one hour after sunset in the northwestern sky. This will be an interesting celestial dance to follow all month. Venus will be getting higher even as Jupiter continues to sink lower after it has been well placed for viewing all fall and winter. Mercury will join the pair of bright planets during the second half of May.
To add to the beauty of this unfolding dance, a slender waxing crescent moon will pass just below Venus and then Jupiter during the evenings of May 10 to 12. Look low in the West-Northwestern sky a half-hour after sunset. You will see Venus just to the left of the Pleiades, also known as the Seven Sisters, and just to the right of the Hyades star cluster, marking the face of Taurus the Bull. The next evening the moon will have moved 12 degrees farther east by the same time. Then, on Sunday evening the 12th, the moon will be a little larger and just to the left and above Jupiter and to the right and above Betelgeuse, the red supergiant star in Orion.
Then continue to watch each clear evening as Jupiter rapidly sinks lower into our western sky even as Venus slowly climbs higher. The three planets will form a straight line about 12 degrees long on May 19. Watch as this line continues to get shorter each evening.
The trio will be within just 5 degrees of each other from the 24th to the 29th. Watch carefully as this trio gets even tighter on May 26. All three planets will fit within a circle less than 2.5 degrees wide. Through a telescope, you will see that Venus is almost fully lit by the sun and about one third the apparent width of Jupiter. Mercury will be about half the size of Venus and is about 70 percent lit by the sun.
By the end of May, the planets will magically realign themselves again into a straight line again, this time with Mercury on top, Venus in the middle and Jupiter closest to the horizon.
Saturn is just past opposition now, so it rises in the east just before the sun sets. It will not form any dramatic conjunctions, but it will be in retrograde or westward motion out of Libra into eastern Virgo this month. The waxing gibbous moon will pass near the ringed planet on the 22nd.
There will also be an annular solar eclipse on May 10, but it will only be visible over parts of Australia and a few Pacific islands. Try to catch a live feed of this eclipse on slooh.com.
Annular means that there is a brilliant ring of sunlight left around the sun since the moon is a little too far from Earth to completely cover the sun, as it would in the much more dramatic total solar eclipse.
An annular eclipse is still exciting since it looks the same as a total eclipse in all of the phases going in and coming out, except for the moment that really counts, when our sun is completely covered by the moon, allowing its beautiful and ever-changing corona, or atmosphere, to become visible. There will be a total solar eclipse right here in this country on Aug. 21, 2017.
The Eta Aquarid meteor shower peaks during the morning of Sunday, May 5. This is usually a much better meteor shower for the tropics and the Southern Hemisphere, where they will see about 60 meteors per hour. We can only expect about half that number up here.
Caused by the most famous of all comets -- Halley's -- tiny, sand grain-size pieces will crash into our upper atmosphere at about 40 miles per second, leaving brilliant streaks knifing through our peaceful, silent, and dark night sky.
• May 2. Last quarter moon is at 7:14 a.m. EDT.
• May 5. The Eta Aquarid meteor shower peaks this morning.
• May 9. New moon is at 8:28 p.m.
• May 11. A waxing crescent moon floats near Jupiter this evening.
• May 18. First quarter moon is at 12:35 a.m.
• May 25. Full moon is at 12:25 a.m. This is also called the flower, milk or planting moon. On this day in 1961, JFK challenged the nation to place a man on the moon before 1970.
• May 27. Jupiter and Venus will be just over 1 degree apart with Mercury right above them.
• May 28. On this day in 1959, the first primates in space, the rhesus monkeys Able and Baker completed a sub-orbital flight.
• May 29. On this day in 1919, Einstein's new theory of General Relativity was successfully tested during a total solar eclipse over Africa and South America.
Bernie Reim of Wells is co-director of the Astronomical Society of Northern New England.