AstroCal – May 2025
Okay, if April showers bring May flowers, what do April snow showers bring? Enough – let spring begin in earnest!! A quick note of ‘thanks’ to those intrepid photographers who have been posting aurora photos on the ‘You Know You Are From Ontonagon’ Facebook page. Though I am not a Facebook subscriber, I do enjoy checking out the wonderful photos. Now, let us get to the business at hand for May, astronomically speaking. Oh yes, do not forget to circle May 3 on your calendar – International Astronomy Day will be observed that Saturday.
May 5 finds us starting the month with the Eta Aquarids meteor shower. Though the Moon will be in its waxing gibbous phase, it should only have a slight effect on our meteor viewing (although the Abrams Sky Calendar warns us to ‘not expect to see many’). The peak will be reached on May 5 but elevated numbers of meteors are typical a day or two ahead of and after the peak. Some may be visible just before dawn with up to 50 meteors per hour predicted for this shower. The meteors will seem to radiate from the star Eta Aquarid in the constellation of Aquarius, the Water Bearer in the east, hence the name..
Look for the First Quarter Moon on May 4, just as the Aquariads are ramping up. The Full Moon will take place on May 12, the Last Quarter Moon on May 20 and the New Moon will begin the next Lunar cycle on May 27. The Abrams Sky Calendar also reminds us that, “Thin crescent Moons are wonderful when viewed with binoculars. Try for the old Moon just before Sunrise in the east on May 26 and an easier, naked-eye Moon with Earthshine at dusk on May 27. Spotting opposing crescent Moons on consecutive days is a very rare accomplishment.” With that, you have been given your Astronomical challenge for May.
On the planetary front, bright Venus (mag -4.7) rises in the east near the start of twilight. As sunrise approaches, binoculars will reveal the planet to be in a crescent phase with 29 percent lit (and a span of 36 “ across on May 1). By the end of the month, the phase will be more challenging at a span of 24” across (while the crescent will have increased to 49 percent). On May 6, Saturn will rise with Venus. Look for it shining at magnitude +1.2 located 5.1 degrees to the right of the brighter planet. May 6 also marks the autumnal equinox for Saturn which happens every 29.4 years when the Rings are seen ‘on edge’ as the Sun’s vertical ray moves to the southern hemisphere. The planet has appeared ringless in this short period prior to May 6 with the shaded side of the rings pointing toward us. That side will slowly begin to be visible as the Sun illuminates them from below and the lit rings will be seen 3.1 degrees from edge on by May 31.
Jupiter remains the bright spot for evening viewing. Jupiter starts the evening in the western sky about and hour before sunset and it will set 3-4 minutes earlier during the month. Watch it slowly pass between the horns of Taurus, the Bull. Look for Mars just below the Moon on May 3. Asteroid Vesta (discovered in 1807) reaches opposition on May 1 and can be seen with binoculars left of the bright star Spica in Virgo, the Virgin (near the star Mu Virgo).
Our historical astronomical event for this month actually took place on April 21, 1972 when Apollo 16 astronauts John Young and Charlie Duke planted the first (and so far only) telescope on the Moon. With the scientific community currently bucking the insane notion of removing examples of inclusion, diversity, equity, and accessibility from our nation’s history, it should be noted that this telescope was the brainchild of an African-American astronomer named George Carruthers (1939-2020).
After earning his PhD in aeronautical and astronautical engineering at the University of Illinois at Urbana-Champaign, Dr. Carruthers accepted a postdoctoral position at the U.S. Naval Research Laboratory where he would spend the rest of his career. His interest in astronomy and space exploration led him to design and build telescopes with a focus on ultraviolet imaging and spectroscopy. After the Apollo 11 mission, Carruthers proposed what would become the Far Ultraviolet Camera/Spectrograph telescope deployed on the Apollo 16 mission. It was a hybrid analog-digital device that produced electrons but recorded the data on film that the astronauts would return to Earth for processing.
In a 1999 interview, Carruthers described the outcome of this investigation: “The most immediately obvious and spectacular results were really for the Earth Observations, because this was the first time the Earth had been photographed from a distance in ultraviolet light. You could see the full extent of the hydrogen atmosphere (geocoronal), the polar auroras, and what we call the tropical airglow belt. All of these things were revealed for the first time…We also obtained UV images of stars [and] the Large Magellanic Cloud.” One can only scratch their head in wonder at how scrubbing events like this from our history makes any sense at all.
Compiled by Ken Raisanen of WOAS-FM 91.5 – information provided by Abrams Planetarium Sky Calendar, Michigan State University. More information and subscription information can be found on their website at http://abramsplanetarium.org/skycalendar/. Yearly subscriptions cost $12 and can be started anytime. Comments and questions can be emailed to kraisanen@oasd.k12.mi.us
Top Piece Video – Aquariads you say? How about Aquarius – Let the Sun Shine In?