At any moment of the day, countless awe-inspiring celestial events are unfolding in the sky. With a universe of options, it can be hard to pin down what to observe. The purpose of this calendar is to provide a peek into what’s happening in the sky and in the world of astronomy in general and give a quick list of highlights that can jump start your own explorations.
May Planetary Round-up:
Our planetary pals are always popular observing targets but knowing when to look for them each month is key. This month, Jupiter and Mars will make evening appearances, while Venus, Saturn and Mercury take up positions in the pre-dawn sky. To enjoy Jupiter, look to the western sky after sunset. By the end of the month, the giant planet will be low on the horizon just after sunset, but you could get a chance to spot it near a very thin waxing crescent Moon. To catch Mars, look for its reddish glow in the southwest. The morning planets are best caught during the twilight period just before sunrise, and on several May mornings Saturn and the ever-bright Venus will actually be fairly close. If you get a chance to peek at Saturn through a telescope, you will likely see only a hint of its rings due to its mostly edge-on positioning in regard to Earth.
Astrophotographer Jim Norwood created this composite using three individual images of Mars, Saturn and Jupiter taken around the same time in October 2020 with the aid of an Explore Scientific iEXOS-100 PMC-Eight mount.
May 2 – Asteroid 4 Vesta at Opposition
The month kicks off with Asteroid 4 Vesta at opposition, which means it is essentially at a position directly opposite of the Sun when viewed from Earth. At the same time, it also will be at its closest approach to Earth. The combination of these factors means the asteroid will be in a prime viewing position within the Libra constellation as it reaches a peak brightness of magnitude 5.7. The asteroid, which is also a protoplanet, will be visible to the naked eye under dark skies, but a pair of binoculars or a small telescope will enhance the observing experience – especially for those with light-polluted skies. Discovered in 1807, Asteroid 4 Vesta is the second most massive body in the asteroid belt.
May 5 –Mars & the Beehive Cluster
Stargazers will be all abuzz when Mars and the Beehive Cluster visually pair up in the night sky early this month. In the march to this close encounter, the two will first get cozy with the waxing crescent moon on the evening of May 3. But during their closest encounter on the evening of May 5, the Red Planet will be positioned just 0.6 degrees NNE of the star cluster. The Beehive Cluster, which is also known as M44, lies about 560 light years away and can be observed with the naked eye. Located in the Cancer constellation, the cluster appears as a cloudy mass at first glance. But when you turn a pair of large aperture binoculars (10x50) or a small rich field telescope on it, its stellar inhabitants blaze to life. Covering more than 1.5 degrees of sky, the Beehive Cluster is home to at least 1,000 stars, with a large portion of those being red dwarfs and about 30 percent of a type similar to our Sun. It also includes some impressive blue-white beauties and a sprinkling of orange giants. Identified as a nebulous mass by the 2nd Century astronomer Ptolemy, M44 has a rich history that includes being one of the first objects studied through a telescope by famed astronomer Galileo, who realized it was actually a star cluster. It also has a strong foundation in the lore of ancient cultures. Also known as Praesepe, which means “manger” in Latin, the Greeks and Romans characterized the cluster as a manger that feeds two nearby stars, Asellus Australis and Asellus Borealis, which were seen to represent two famous donkeys that were key in a battle with the Titans.
May 5/6 – Eta Aquariids Meteor Shower Peaks
Although its run stretches from mid-April to late-May, the annual Eta Aquariid meteor shower is set to reach its full potential in the pre-dawn hours of May 5th and 6th, which is perfect timing considering the waxing Moon sets hours before dawn on both nights. The shower is caused by the Earth’s passage through debris left behind by the famous Halley’s Comet, which is also the source for another meteor shower - the Orionids - every October. Especially amazing for southern hemisphere observers, who could be treated to 50 or more meteors per hour, the Eta Aquarids appear to radiate from the Aquarius constellation. However, observers should actually look at a dark patch of sky about 90 degrees away from the radiant point to see the most meteors. To view the Eta Aquarids meteors, all you need is your naked eye, a good place to lie down under an open sky and patience.
May 11 – Messier 5
Around mid-May, deep sky enthusiasts will want to turn their binoculars or telescopes to the Serpens constellation and take a deep dive into the globular cluster known as Messier 5. With a radius of 80 lightyears, this ball of beautiful stars is one of the oldest globular clusters in our own Milky Way galaxy.
May 31/June 1 – Venus at Greatest Elongation
As the third brightest object in the sky, Venus is consistently an inspiring celestial target for both casual and avid sky watchers. But in the pre-dawn skies of June 1 (4 UTC), the brilliance of Venus will be even more pronounced as the planet reaches its greatest western elongation or its furthest point to the west of the Sun. Although visible to the naked eye at a magnitude of -4.4, a small telescope will further define Venus, which will be in a third quarter phase. Just look in the direction of sunrise to witness the spectacle.
Constellation Spotlight:
Virgo Constellation
Offering up a feast of intriguing galaxies, the Virgo constellation is an ideal May target for stargazers in either hemisphere. As the second largest constellation, Virgo covers 1,294 square degrees of celestial real estate and is visible from 80° North to 80° South.
Before dipping into all of Virgo’s galactic offerings, a new observer can get their bearings by locating the constellation’s standout star - Spica. Also known as alpha Virginis, this multi-star system dominated by a blue giant has an apparent visual magnitude of 1.04. To easily locate Spica, find the Big Dipper asterism and follow the arc of its handle as it points to Arcturus, an orange giant star in the Bootes constellation. Once your eye finds Arcturus, continue to follow the same gentle curve to the blue-white beauty Spica. Some of Virgo’s other stellar treats include Porrima, a binary star system that can only be resolved with large aperture telescopes; Auva, a red giant with variations in brightness; Vindemiatrix, a yellow giant with an apparent visual magnitude of 2.826; Heze, a white dwarf; and Zavijava, an often-occulted pale star that stays cozy with the ecliptic plane and gained a bit of notoriety when it was used by Einstein in 1922 to determine the speed of light in space.
Virgo really starts to shine when it comes to deep sky observing targets. One of Virgo’s most dynamic deep sky treasures is the Sombrero Galaxy (Messier 104), which is located about 11.5° west of Spica. Featuring between 1,200 to 2,000 globular clusters, this unbarred spiral galaxy has a bright bulging center ringed by a pronounced dark dust lane. The huge constellation also is home to the massive Virgo Cluster, which teems with a versatile mix of well over a thousand galaxies. Among its offerings are Messier 49, an elliptical galaxy with a 9.4 visual magnitude that makes it the cluster’s brightest member; Messier 87, a giant elliptical galaxy with a 9.59 visual magnitude that lies near Virgo’s border with the Coma Berenices constellation; Messier 58, a barred spiral galaxy; and the lenticular galaxies Messier 84 and Messier 86. The cluster also includes the Siamese Twins (NGC 4567 AND NGC 4568), which are colliding spiral galaxies; the Eyes Galaxies, which includes the barred lenticular NGC 4435 and the hard-to-categorize NGC 4438; the bright Messier 88 and Messier 90 spiral galaxies and the challenging Messier 91 barred spiral galaxy.
WANT TO NAVIGATE THE NIGHT SKY WITH EASE?
The Tirion Double-Sided Multi-Latitude Planisphere is a comprehensive sky map for northern hemisphere stargazers located between the equator and latitude 60° north that makes it easy to identify what constellations and major celestial objects are up in your night sky based on the date and time.
This night sky guide, which features maps crafted by noted celestial cartographer Wil Tirion, uses a double-sided design to minimize the distortion that is inherent to any polar-centered projection. This design choice means observers can see truer representations of the constellations located outside the equator (noted by a green line) by simply flipping the planisphere over.
In addition to showcasing constellations, this planisphere indicates the location of notable variable stars, open clusters, nebulae and galaxies. Other features include a line representing the ecliptic, a faint blue band for the Milky Way and a magnitude scale that indicates the brightness of the stars that are shown.
This astronomy planisphere is made of durable plastic that easily wipes clean, and the rotating components are secured with sturdy brass rivets for smooth manipulation. Guidance for using your sky map is printed on the device for quick reference.