March 2021
March brings the start of spring - also known as “Galaxy Season” to astronomers everywhere - and there’s a fine pair to be found in the constellation of Leo, the Lion. The galaxies were discovered simultaneously by the French astronomer Charles Messier on March 1st, 1780, who noted that they both appeared within the same low powered field of view.
Of the two, M66 is slightly larger and brighter, with small scopes showing a sizable halo with a bright, oval core. Larger scopes (250mm or more) will reveal some mottling, with dark bands near the core and the possibility of seeing the spiral arms. It’s a similar story with M65, with an extended halo toward the south. Lastly, look out for NGC 3628, a magnitude 10 galaxy located toward the northeast.
Image source: Bill Snyder
After a relatively quiet February, things begin to pick up in March. Both Venus and Neptune are lost within the Sun’s glare, but Uranus can still be seen for about three hours after sunset. Look out for a thin crescent Moon within the same binocular field of view on the evening of the 16th. Mars continues to move through Taurus (see below); it passes the Hyades around the middle of the month and is joined by the Moon on the 19th. Meanwhile, if you’re an early riser, you can catch Saturn in the predawn twilight. It rises a few hours before the Sun and is then joined by Jupiter and Mercury a short while later. Look out for a close conjunction of Jupiter and Mercury above the southeastern horizon on the 5th, with the waning crescent Moon to the lower right of Jupiter on the 10th. The Moon then turns new on the 13th and full on the 28th.
Image credit: ESA & MPS for OSIRIS Team
Just as Venus passed the Pleiades last April, Mars now does the same. You’ll find it within the same 10x50 binocular view from the start of the month to around the 11th. At their closest, on the 3rd, about two and a half degrees will separate the pair.
Image credit: Goran Nilsson
Barely visible as a dark gray disc in small scopes, a larger scope (250mm or more) will show the owl’s eyes as two diffuse patches.
Image credit: Sloan Digital Sky Survey
This compact cluster may be glimpsed with binoculars and consists of faint, blue-white stars with an orange star on its northeastern edge. You’ll find it just to the west of the star Acubens in Cancer.
Image credit: New Forest Observatory
Regulus is the brightest star in Leo, the Lion, and lies just half a degree from the ecliptic, the path the Sun, Moon, and planets take across the sky. Look for the Moon nearby on the 25th.
Albedo: The amount of sunlight an object reflects, which, on the Bond scale, is given as a value ranging from 0 to 1. An object with an albedo of 0.0 would reflect 0% of the light striking it, whereas an object with an albedo of 1.0 would reflect 100% of the light. For example, Proteus, a small moon of Neptune, has an albedo of just 0.096 and reflects about 10% of the sunlight striking it. On the other end of the scale is Enceladus, a moon of Saturn, which has an albedo of 0.81, while the Earth has an albedo of 0.31 and the Moon has an albedo of 0.11.