Our charts are mostly set for the northern half of Earth. To see a precise view from your location, try Stellarium Online.
See the moon near Spica
From time to time, you’ll notice a close pairing of the moon and a bright star or planet. These eye-catching scenes will have even non-astronomy fans turning their heads for a second look. As a bonus, the moon is an excellent guide to learning stars and planets.
About an hour before sunrise on December 18, look for the waning crescent moon shining near Spica. Spica is the only 1st-magnitude star in Virgo the Maiden. And it lies very near the ecliptic, or yearly path the sun follows through the sky. Also, the moon and planets follow this same path.
A closer look at Virgo’s brightest star
Spica is the 15th brightest star in our nighttime sky. In fact, it resides some 260 light-years from our solar system. So, this star must be intrinsically very luminous to shine at 1st magnitude brightness in Earth’s sky.
Spica appears to us on Earth to be a single bluish-white star in a quiet region of the sky. But Spica consists of two stars and maybe more. The pair are both larger and hotter than our sun, and they’re separated by only 11 million miles (less than 18 million km). And they orbit their common center of gravity in only four days.
Because Spica is only 2 degrees from the ecliptic, occasionally the moon will occult – pass in front of – Spica. As a matter of fact, the next series of the moon passing in front of Spica starts in 2024, when the moon will occult Spica each month for a total of 20 times.
Bottom line: Use the waning crescent moon on the morning of December 18, 2022, to locate the bright star Spica. Spica is the brightest star in Virgo the Maiden.
For more great observing events in the coming weeks, visit EarthSky’s night sky guide