The Full Sturgeon Moon will occur on Aug. 19, at 2:26 p.m. EDT (1826 UTC), according to the U.S. Naval Observatory.
The moon will occult the planet Saturn the next day, and will also be an almost-"supermoon" as it happens just two days before the moon is closest to Earth; on Aug. 21.
A moon is full when it is exactly on the opposite side of the Earth from the sun. Timing depends on one's time zone. Occultations refer to when one celestial body passes in front of another; this is not the same as an eclipse, which refers to when the shadow of one body obscures another. When the moon passes in front of Saturn that's an occultation. And yes, the word "occult" is related — both refer to something hidden.
The timing of the full moon depends on one's time zone because lunar phases are measured according to the longitudinal position of the moon relative to the Earth against the sky; one's latitude doesn't alter the timing as it would with moonrise and moonset. If one is in Los Angeles, for example, the full moon is at 11:26 a.m. on Aug. 19, whereas in London it is at 7:26 p.m. In New Delhi, the full moon is at 11:56 p.m. local time, and further east the full moon is on Aug. 20 — in Tokyo, the moon reaches full phase at 3:26 a.m. and in Melbourne, Australia, it is at 4:26 a.m.
Related: Full moon calendar 2024: When to see the next full moon
With the full moon on the opposite side of the sky from the sun — exactly 180 degrees away — summertime full moons in the Northern Hemisphere are lower in the sky. The effect is most pronounced in June and July, but even in August observers in mid-northern latitudes will see the moon about 30 to 40 degrees above the southern horizon at its highest (depending on how far north or south one is). The farther north one is the lower the moon appears.
Occultation of Saturn
The occultation of Saturn won't be visible from everywhere. The moon is quite close relative to stars and planets; one's position on Earth can visibly alter the apparent position of the moon against the background stars by up to two degrees (just under four lunar diameters). Observers in areas where the occultation isn't visible will see the moon make a close pass to the ringed planet; Saturn will appear to pass above or below the moon depending on one's latitude.
The moon's relative proximity also makes it appear to move eastwards against the background stars as it travels in its orbit; careful observers can see the moon move approximately one of its own diameters every hour. This is why we see the moon pass in front of Saturn, or any other bright object, in a relatively short time.
The full occultation start to finish will be visible from the northern half of South America, western Europe and northwestern Africa. The start of the occultation will be visible in eastern Europe and the emergence of Saturn will be visible from western South America.
In Berlin, for example, the occultation starts at 5:34 a.m. local time (0334 UT) per the International Occultation Timing Association (IOTA), and ends at 6:30 a.m. local time, but Saturn emerges from behind the western side of the moon during the day, as sunrise there is at 6:00 a.m.
As one moves westwards the moon and Saturn are higher in the sky when the occultation happens. From Paris, where the sunrise is at 6:52 a.m., the occultation begins at 5:28 a.m (0328 UT) with Saturn emerging from behind the moon at 6:26 a.m. (0426 UT), according to IOTA; the moon will be at about 26 degrees high in the southwest at the start.
In Lisbon, Saturn disappears behind the moon at 4:11 a.m. local time (0311 UT) and reappears at 5:19 a.m. (0419 UT). The sky will still be dark — astronomical twilight is only just beginning at that point, and sunrise is at 6:56 a.m. The moon will be some 41 degrees above the horizon.
From Africa it gets easier as the moon will be still higher; in Marrakech, Morocco, the occultation begins at 4:07 a.m. local time and ends at 5:16 a.m.; sunrise isn't until 7:01 a.m., and the moon will be at an altitude of about 47 degrees when the occultation starts.
On the other side of the Atlantic, the occultation starts before midnight. In the city of Natal, Brazil, it begins at 10:38 p.m. local time, and ends at 11:27 p.m. The moon will be 60 degrees high in the east. In Quito, Ecuador, Saturn touches the moon at 7:51 p.m. local time and emerges at 8:47 p.m. — but the moon rises at 7:26 p.m. and will only be about 5 degrees high when the occultation begins.
From North America observers will see the moon make a close pass to Saturn rather than an occultation; in New York City the moon will be 27 arcminutes — a bit less than one lunar diameter — to the north of Saturn at 11:01 p.m. August 20. From Chicago, it will be at 10:01 p.m. local time, according to skywatching site In-the-sky.org
As one gets out of the Americas and Europe the moment of closest approach between our satellite and Saturn won't be visible, but the two will still be close together in the sky. In Melbourne, Australia, for example, the nearly-full moon rises at 7:38 p.m. on Aug 21 and Saturn at 7:12 p.m.; Saturn will appear to be above the moon.
The August full moon will appear slightly larger than normal; this is called a "supermoon" though it's not a real astronomical term. To be a supermoon the full moon has to be at the closest point in its orbit to the Earth; this time it won't be on the exact day of the full moon but two days later. This happens because the lunar orbit isn't a perfect circle. At its closest, the moon is 226,000 miles (363,300 kilometers) from the center of the Earth; at its farthest it is 253,000 miles (405,500 kilometers).
Even with that 27,000-mile change, it's hard to see the difference unless one is a very careful observer — the apparent change in the moon's size is only about 10 to 11 percent; most people don't notice. Supermoons don't happen every month (or more accurately, every 29.5 days) because the longer dimension of the moon's orbit doesn't stay pointed in the same direction relative to the Earth; it slowly rotates.
Visible planets
On Aug. 19, from mid-northern latitudes, Venus will be just visible in the west, if one has a clear sky. In New York, where sunset is at 7:47 p.m., Venus sets at 8:43 p.m. EDT. At sunset the planet is only about 10 degrees above the horizon, so one will have to try spotting it as the sky darkens.
Jupiter and Mars will both rise just after midnight and will be side by side in the sky, making a rough line with Aldebaran, the brightest star in Taurus, the Bull. Aldebaran and Mars are both visibly reddish-orange, so Jupiter, which is more yellow-white, will stand out between them. In New York, Jupiter is the first to rise at 12:40 a.m. on Aug. 20, with Mars following at 12:49 a.m.
In Southern Hemisphere locations Venus will be easier to see; as it is still winter there the nights are longer and the sun sets earlier. In Melbourne, for example, on the evening of the full moon (Aug. 20) sunset is at 5:49 p.m. and Venus sets at 7:29 p.m.; at sunset, the planet is about 18 degrees high in the west and it will be one of the very first astronomical objects to become visible as the sky gets darker; aa half hour after sunset the planet will still be about 12 degrees above the horizon.
Jupiter rises in the wee hours of Aug. 21, at 2:39 a.m., followed by Mars at Aug 21, at 2:54 a.m. Both will be in the northeast, and Jupiter will appear above Mars as the sky is "upside down" in the Southern Hemisphere (from the perspective of denizens of the Northern Hemisphere). As in northern latitudes Jupiter is framed by Mars and Aldebaran, though in this case, Aldebaran is upwards and to the left of Jupiter.
Moon Lore
The August full moon name in the Farmer's Almanac is the Full Sturgeon moon because the eponymous fish are more easily caught in August and early September. Sturgeons are native to both Europe and the Americas; the name (for the moon, not the fish) likely came from both colonists and Algonquin-speaking peoples in northeastern North America. Other Native peoples had differing names for the August lunation; in the Pacific Northwest the Haida called it the "Salmon Moon" (Chiín Kungáay) since salmon were a much more important fish to them than sturgeon,
The Chinese lunar calendar lunation containing the August full moon is the seventh lunar month, called Qiǎoyuè (巧月) or Skill Month. On the Jewish calendar, this full moon falls in the 15th day of the month of Av, a day called Tu'Bav, considered auspicious for weddings. In the Islamic calendar, the August full moon falls on the 15th day of Safar, the second month.
In some Hindu traditions, the lunar months begin on the day of the full moon rather than the new moon, and this full moon would mark the start of the sixth month, called Bhādo in Hindi and Bhādrapada in Sanskrit. The first day occurs on Aug. 20 since the full moon occurs so close to midnight in India; at 11:56 p.m. on Aug. 19.
One reason for the difference in the numbering of months between calendars is that lunar months differ from the 30- and 31-day months of the Gregorian calendar. A lunar month is close to 29.5 days (the time between successive new moons or full moons). That means 12 lunations are about 11 days short of the 365-day solar year (really, 365 and one-quarter days). Some lunar calendrical systems add what is called an intercalary month — an "extra" 13th month to keep the months in step with the seasons; the Chinese calendar will add one next year, for example, and the Jewish calendar added one in 2024. Islamic calendars do not use this system; the months and days are allowed to "drift" against the Gregorian date.
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