On August 16, 2017 – in the predawn hours – people around the world will see the moon shining quite close to Aldebaran, brightest star in the constellation Taurus the Bull. You’ll also see the constellation Orion the Hunter near the eastern horizon shortly before dawn’s first light. The moon will be there to show you Aldebaran this week, but note that Orion’s Belt points this star. That’s how you can find it, after the moon has left this part of the sky.
If you were at just the right spot on Earth on the morning of August 16 – the Caribbean, northeastern tip of South America and North Atlantic Ocean – you could watch the waning moon occult (or cover over) the star Aldebaran in the wee hours of the morning on August 16. Even though most of the world will not see this occultation, the moon and Aldebaran will still be close together on the morning of August 16. Given clear skies, the moon and Aldebaran should be yours to behold.
Note the worldwide map below. Everyplace within the solid white lines is in a position to observe the lunar occultation of Aldebaran in the predawn sky on August 16. To the right side of the solid white lines, the short blue lines show where the occultation takes place at morning dawn on August 16. The The dotted red lines show where the occultation happens in a daytime sky on August 16. From anyplace in the viewing area, Aldebaran will disappear behind the moon’s daytime side and then reappear on the nighttime side.
For your convenience, we list some occultation times in local time below:
Lunar occultation of Aldebaran on August 16, 2017
Occultation starts (Aldebaran disappears): 12:57 a.m. local time
Occultation ends (Aldebaran reappears): 1:53 a.m. local time
Paramaribo, Suriname, South America
Occultation starts (Aldebaran disappears): 1:57 a.m. local time
Occultation ends (Aldebaran reappears): 2:41 a.m. local time
Nouachott, Mauritania, Africa
Occultation starts (Aldebaran disappears): 5:55 a.m. local time
Occultation ends (Aldebaran reappears): 6:24 a.m. local time
Occultation starts (Aldebaran disappears): 11:20 a.m. local time
Occultation ends (Aldebaran reappears): 12:22 p.m. local time
Click here to find out the occultation times for well over a thousand localities in Universal Time. You must convert to your local clock time to know when Aldebaran disappears behind the lit side of the moon and then reappears on the moon’s dark side.
This month’s occultation of Aldebaran is part of a series of 49 monthly occultations of this star by the moon. The first occultation of this series of started on January 29, 2015, and the final occultation of the series will conclude on September 23, 2018.
But no matter where you live worldwide, look for the moon to shine in the vicinity of the star Aldebaran during the predawn hours on August 16, 2017.
Bottom line: If you’re a night owl or early bird, watch the moon pass in front of the constellation Taurus the Bull over the next few days.
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.