February’s crisp air provides a clear view of our dark New Mexico skies. Cold air vibrates more slowly, which allows for better viewing. Low precipitation, pollen counts, and wind speeds favor early to mid-month sky gazing. With a new moon on the 15th, Valentine’s Day is a great time to catch faint objects such as galaxies and globular clusters with telescopes or binoculars. One such object, M31, known more commonly as the Andromeda galaxy, will display prominently in the northwestern sky just after dark. To find it, look for the big, open W standing on its side. That is the constellation Cassiopeia. What would be the bottom-right corner of that W makes an arrow that points to a small fuzzy patch in the sky about a fist’s width at arm’s length to the west—that’s M31. At 2.5 million light-years away and as many as a trillion individual stars, it is our closest large galactic neighbor. Careening toward us at 68 miles per second, M31 will merge with the Milky Way in 4 billion years. It’s romantic to think of this spiral galaxy eventually filling our future night sky, isn’t it?
Parallax | Go. See. Do. | February 2018