For March 2024, the last quarter moon gives us a real treat on the morning of March 2, when it occults the bright star Antares in Scorpius. For observers, the red supergiant vanishes behind the center of the bright half moon at 12:58 AM, and will reappear at 2:58 a.m., coming out from behind the northwest limb of the dark side of the lunar disk. Long exposure shots showing the dark side lit by earthshine, with a video of the moon’s reappearance should be awesome! Also note that Antares is a close binary star, and its fainter greenish companion may stand alone for a second of so before its primary reappears about 2:57 a.m..
The waning crescent makes a nice pairing to the right of bright Venus and much fainter Mars on the morning of March 7th. The new moon is on March 10th, and the next new moon is the total solar eclipse crossing the middle of America. March 10th also is the day we "spring forward". The moon Venus will disappear into the sun’s glare in the next week, but Mars climbs higher in the dawn this month.
On the evening of March 11th, look for the waxing crescent moon above Mercury in the twilight. The Moon passes north of Jupiter on March 13th. It is high overhead as first quarter on March 16th. The vernal equinox occurs at 10:06 p.m. on March 19th to begin spring in the northern hemisphere. The full moon moves through our lighter penumbral shadow on the morning of March 25, with the slight darkening most noticeable about 3 a.m.. The waning gibbous moon returns to Antares on March 30th, marking the 27 day sidereal period as the moon revolves through the starry background.
We have a promising comet, named Pons-Brooks, in the western sky heading sunward now. It has already had several unexpected outbursts, once even developing "horns" telescopically, and may be visible with the naked eye near Jupiter at month’s end.
As noted earlier, it is not a good month for seeing the planets. Mercury is in the western twilight, Venus headed behind the Sun, Mars low in the dawn, Jupiter in the SW to disappear behind the Sun next month, and Saturn on the other side of the Sun.
The constellation Cassiopeia makes a striking W in the NW. South of Cassiopeia is Andromeda’s hero, Perseus. Between him and Cassiopeia is the fine Double Cluster, faintly visible with the naked eye and two fine binocular objects in the same field. Perseus contains the famed eclipsing binary star Algol, where the Arabs imagined the eye of the gorgon Medusa would lie. It fades to a third its normal brightness for six out of every 70 hours.
At Perseus’ feet for the famed Pleiades cluster; they lie about 400 light years distant, and over 250 stars are members of this fine group. East of the seven sisters is the V of stars marking the face of Taurus the Bull, with bright orange Aldebaran as his eye. The V of stars is the Hyades cluster, older than the blue Pleiades, but about half their distance. Yellow Capella, a giant star the same temperature and color as our much smaller Sun, dominates the overhead sky in the northwest. It is part of the pentagon on stars making up Auriga, the Charioteer (think Ben Hur). Several nice binocular Messier open clusters are found in the winter milky way here. It also contains some faint but beautiful nebulae, and this one is just right for the coming of spring with frogs hopping and crocking. IC 410, nicknamed the Tadpoles, is a region of star birth.
East of Auriga, the twins, Castor and Pollux highlight the Gemini; it is directly above us as darkness falls in early March. Astronomers associated the pair with Jason and the Golden Fleece legend, for they were the first two Argonauts to sign up on his crew of adventurers.
South of Gemini, Orion is the most familiar winter constellation, dominating the southern sky at dusk. The reddish supergiant Betelguese marks his eastern shoulder, while blue-white supergiant Rigel stands opposite on his west knee. How bright does Betelguese appear to you tonight? In 2019-20, this famed supergiant had expanded and cooled, forming a dust envelope that has darkened much of its southern hemisphere it to less than a quarter its normal brightness in visible light. Now the dust has dissipated, and it is back close to its normal brightness as the alpha star of Orion again.
Just south of the belt, hanging like a sword downward, is M-42, the Great Nebula of Orion, an outstanding binocular and telescopic stellar nursery. The bright diamond of four stars that light it up are the trapezium cluster, one of the finest sights in a telescope and among the youngest known stars.
In the east are the hunter’s two faithful companions, Canis major and minor. Procyon is the bright star in the little dog, and rises minutes before Sirius, the brightest star in the sky. Sirius dominates the SE sky as darkness falls. At 8 light years distance, Sirius is the closest star we can easily see with the naked eye. When Sirius is highest, along our southern horizon look for the second brightest star, Canopus, getting just above the horizon and sparkling like an exquisite diamond as the turbulent winter air twists and turns this shaft of starlight, after a trip of about 200 years!
To the northeast, look for the bowl of the Big Dipper rising, with the top two stars, the pointers, giving you a line to find Polaris, the Pole Star. It sits unmoving 30 degrees high in on our northern sky.
If you take the pointers of the Big Dipper’s bowl to the south, you are guided instead to the head of Leo the Lion rising in the east, looking much like the profile of the famed Sphinx. The bright star at the Lion’s heart is Regulus, the "regal star". The folk wisdom that "March comes in like a Lion" probably refers to the head of Leo rising just after sunset in early March eastern twilight.
The constellation Cancer lies midway between the Gemini to the west and Regulus east of it. Almost directly overhead when darkness falls at month’s end, look under dark skies for a faint blur of light in the middle of the four stars that make up the crab’s body. This is the Praespe, or Beehive, cluster, M-44, familiar to the ancients. Its blurry appearance led Charles Messier to include it in his catalog of things that look at first like comets, but do not move and are far away among the stars and galaxies. Now check it out with binoculars, and resolve it into dozens of stars, hence the "Beehive"!
If you follow the handle of the Big Dipper to the south, by 9 PM you will be able to "arc to Arcturus", the brightest star of Spring and distinctly orange in color. Its color is an indication of its uniqueness. Its large speed and direction through the Milky Way suggests it was not formed with our Galaxy, but is a recent capture from the Sagittarius Dwarf Galaxy, a smaller satellite galaxy now being assimilated by our huge spiral galaxy. Many of its lost stars, like Arcturus, follow a band across the sky at about a 70 degree angle to our galactic plane.
Arcturus is at the tail of kite shaped Bootes, the celestial bear driver chasing the two bears from his flocks. Spike south then to Spica in Virgo. Here appearance to the Greeks marked the time to plant, for they associated Virgo with Persephone, daughter of Ceres of the Harvest, returning from six months underground with Pluto to now bless the growth and greening of the upperworld. So when Spica rises now at sunset in the SE, it is time to plant your peas! Likewise, when Persephone goes back down to Hades and disappears in the sun’s glare in September SW skies, it is time to get your corn in the crib! This cycle goes back to the birth of agriculture.
