Tonight – February 5, 2017 – residents of North America will see the moon to the east of Aldebaran, the brightest star in the constellation Taurus the Bull. As always, the dark side of the waxing moon points eastward while the lit side points westward.
Look at the above chart, which is designed especially for North America. On this date in Asia, Australia and New Zealand, the moon will actually be offset toward the previous date(s). That part of the world will see the moon to the west of Aldebaran as darkness falls on February 5 – and to the east of Aldebaran as darkness falls on February 6.
From southern Europe and northern Africa, the moon will also be offset toward the previous date(s), although less so. In fact, from that part of the world, the moon will actually occult (move right in front of) Aldebaran during the nighttime hours tonight (February 5). Aldebaran will disappear behind the moon’s dark side and reappear on the moon’s illuminated side. For instance, at Lisbon, Portugal, the occultation will take place tonight, on February 5, from 9:48 p.m. to 10:59 p.m. local time. Click here for the occultation times for numerous localities in Universal Time. Here’s how to convert Universal Time to your local time.
At present, there is a series of 49 monthly occultations of Aldebaran that started on January 29, 2015, and which will end on September 3, 2018. To witness any one of these occultations, however, you have to be at the right spot on Earth. We in the United States will miss out this time around, but we’ll have our chance to view the lunar occultation of Aldebaran on the night of March 4, 2017.
Bottom line: No matter where you reside on Earth, let the moon be your guide to the star Aldebaran on February 5, 2017.
Bruce McClure has served as lead writer for EarthSky's popular Tonight pages since 2004. He's a sundial aficionado, whose love for the heavens has taken him to Lake Titicaca in Bolivia and sailing in the North Atlantic, where he earned his celestial navigation certificate through the School of Ocean Sailing and Navigation. He also writes and hosts public astronomy programs and planetarium programs in and around his home in upstate New York.