On October 5, 2019, the moon will be at or near its first quarter phase, coupling up with the planet Saturn on the sky’s dome. What’s more, the lit side of the moon will be pointing at the blazing planet Jupiter beneath the moon and Saturn. Watch for the celestial drama to illuminate the movie screen of the sky as soon as darkness falls.
The first quarter moon comes on October 5, 2019, at 16:47 Universal Time (UTC). Then, some four hours later, the moon passes 0.3 degree to the south of Saturn, at 20:48 UTC. For reference, 3/10 or 0.3 of a degree is about 3/5th the moon’s angular diameter.
When an astronomical almanac states that the moon and Saturn are 0.3 of a degree apart, it really means as viewed from the center of the Earth. But as viewed from the Earth’s surface, the distance between these two luminaries is not the same worldwide. The farther north you live on the Earth’s globe, the farther that the moon swings to the south of Saturn; and the farther south you live, the closer that the moon swings to Saturn.
South of the equator, it’d actually be possible see the moon occult (cover over) Saturn from a sizable swath of the Southern Hemisphere. If you’re at the right spot worldwide, you can watch the moon disappear behind the moon’s dark side and then reappear on its illuminated side. The worldwide map below, via the International Occultation Timing Association (IOTA) shows where the lunar occultation of Saturn takes place on October 5, 2019.
For us in the mainland United states, the first quarter moon occurs during the daylight hours on October 5, at 12:47 p.m. EDT, 11:47 a.m. CDT, 10:47 a.m. MDT and 9:47 a.m. PDT. At US time zones, the moon swings south of Saturn during the daylight hours on October 5, 2019, at 4:48 p.m EDT, 3:48 p.m. CDT, 2:48 p.m. MDT and 1:48 p.m. PDT.
By the time darkness falls to North America on October 5, 2019, the moon will be slightly past first quarter, and the moon will be somewhat to the east (or southeast) of Saturn. From Europe and the most of Africa, you’ll see the first quarter moon to the south or slightly southwest of Saturn. From Asia, Australia and New Zealand – as darkness falls on October 5, 2019 – look for the moon to be a little shy of first quarter phase and to the west (Jupiter side) of Saturn. If you don’t know which way is west, keep in mind that brilliant Jupiter lies to the west of Saturn.
No matter where you live worldwide, look first for the moon and that nearby bright “star” will be the planet Saturn.
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.