Tonight and tomorrow – January 25 and 26, 2015 – use the moon to find three stars outlining the head of the constellation Aries the Ram (Hamal, Sheratan and Mesartim). Then, when the moon moves out of the evening sky in the second week of February 2015, use these three stars to find an elusive galaxy – Messier 74 – also known as the Phantom galaxy.
These next few evenings, the waxing crescent moon passes to the south of the Phantom galaxy and the contellation Aries the Ram. You may need to block out the moon (and/or use binoculars) to see the three stars that depict the head of Aries the Ram.
In their order of brightness, the three stars of Aries are Hamal, Sheratan and Mesartim. The star Eta Piscium in Pisces may be hard to see because of the moonlit glare, but this star is fairly easy to pick out on a dark, moonless night. For the mainland United States, the half-lit first quarter moon occurs on the evening of January 26, at precisely 11:48 pm EST, 10:48 p.m. CST, 9:48 p.m. MST or 8:48 p.m. PST. By Universal Time, the first quarter moon happens on January 27, at 4:48 UTC.
Sky chart of the constellation Aries the Ram
Practiced stargazers often star-hop to M74 (the Phantom galaxy), using the three Aries’ stars and Eta Piscium. You might be able to spot the star Eta Piscium with binoculars tonight. Will you see M74? No way! Of the more than 100 Messier deep-sky objects cataloged by the famous comet hunter, Charles Messier, this galaxy is one of the hardest to see in a telescope.
Yet M74 – the Phantom galaxy – is a fascinating object. It has the lowest surface brightness of all the Messier objects because it is a face-on spiral galaxy some 35 million light-years away.
Our eyes can’t see the galaxy like this. Even in amateur telescopes, M74 is barely visible. It is best viewed under low magnification. Telescope users practice averted vision when seeking this galaxy. In other words, like many sorts of ghosts, it disappears when you look at it directly.
You don’t really need a super high-powered telescope to see the Phantom galaxy, but you do need an inky dark night, transparent sky and dark-adapted eyes. Every March, when it’s technically possible (though difficult) to spot all the Messier objects in one night, M74 is one that is commonly missed. Here’s more about the annual Messier Marathon, with tips on how to spot M74.
Bottom line: The moon on the nights of January 25 and 26, 2015 can help you find the three noticeable stars of the constellation Aries the Ram. And then – after the moon moves away from this part of the sky – those three stars could (if you had a telescope) help you find the Phantom galaxy, M74.