Although the moon and Spica appear close together on the sky’s dome, they are actually nowhere close in space. Tonight’s moon resides about one and one-third light-seconds distant from Earth while Spica lies far beyond the moon, at about 260 light-years away.
The March full moon came to pass on March 23, at 12:01 Universal Time. Although the full moon happened at the same instant worldwide, the clock read differently by time zone. At our U.S. time zones, the full moon occurred on July 23, at 8:01 a.m. EDT, at 7:01 a.m. CDT, 6:01 a.m. MDT or 5:01 p.m. PDT.
This evening, as the moon rises over the eastern horizon at dusk or nightfall, the moon will probably appear full to the eye. It’ll still be about 98% illuminated by sunshine, as seen from North America.
If we could whisk you off to where you could view the moon’s far side, you’d see an exceedingly slender waxing crescent moon. In other words, the moon’s far side would be almost completely dark, almost totally engulfed in the moon’s own shadow.
We’ve found over the years that people tend confuse the moon’s far side with its dark side. The moon’s far side – or back side – is the half of the lunar globe that we can’t see from Earth. The dark side is the side that lies opposite the sun. The far side is only the dark side at full moon.
Although the moon has a permanent far side, it has no permanent dark side. Everyplace on the moon gets about two weeks of night followed by two weeks of day.
Bottom line: Tonight – March 24, 2016 – enjoy seeing the almost-full waning gibbous moon near Spica, the brightest star in the constellation Virgo the Maiden.
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.