Driftless Dark Skies

Feb. 15 is the 455th birthday of Galileo Galilei. He is beloved by stargazers because he was the first of us to observe the starry sky with a telescope and to share the news with the world that the Milky Way is full of stars, the sun has spots, the moon is a world, Jupiter has moons, Venus has phases and Saturn has “ears.”
February is a great month to see the moon through the eyes of Galileo. Ordinary binoculars are closest in size and magnification to the telescope Galileo crafted and used four centuries ago. Begin the morning of Feb. 1 when the waning crescent moon is in the southeast sky between Venus and Saturn. The following morning, the moon has waned even more and moved closer to Saturn. Best view in the Driftless is 6-6:30 a.m. Be sure to notice the Earthshine on the dark side of the moon and how the shadows heighten the features along the terminator — the line separating light/dark and night/day where the sun is setting on the lunar landscape.
The moon is too close to the sun in the days around New Moon (Feb. 4) to observe, but look for it again the evening of Feb. 6 in the southwest after sunset at 5:18 and before moonset at 7:09. Now the terminator marks where the sun is rising on the moon as craters and mountains are illuminated at dawn. On Feb. 10, the moon is the same phase (about a third illuminated) as it was on July 20, 1969, when Neil Armstrong and Buzz Aldrin explored the Sea of Tranquility as the sun was rising there. You can spot this darker area just to the right of the terminator along the lunar equator halfway between the “horns” of the moon. Just above the moon is ruddy Mars.
On the night of Feb. 12, the terminator equally divides the first quarter moon. On Feb. 15, celebrate Galileo’s birthday by enjoying the waxing gibbous moon just above Orion the Hunter and surrounded by the bright stars of the Winter Circle. The Full Snow Moon on Feb. 19 is an excellent time to see the three great ages of lunar geology. The light areas are the lunar highlands with the original crust of the moon from the Age of Formation. The craters and the rays of ejecta cast out from them are from the Age of Bombardment. The dark areas are maria, basaltic plains from the Age of Lava Seas.
Last Quarter is Feb. 26, and now the terminator marks where night is falling. On the morning of Feb. 27, Jupiter is right below the waning gibbous moon. Best view is after moonrise at 2:04 and before sunrise at 6:41. If you can hold your binoculars steady enough, you might be able to glimpse the four Galilean Moons of Jupiter first discovered by Galileo — Io, Europa, Ganymede and Callisto. Magnifico!

John Heasley is an astronomy educator and stargazer who enjoys connecting people with the cosmos. For more information about stargazing in southwestern Wisconsin, like Driftless Stargazing LLC on Facebook and find out whenever there’s something awesome happening in the skies above.