The full moon of June, also known as the Strawberry Moon, arrives in the wee hours of Thursday, June 28, at 12:53 a.m. EDT (0453 GMT). Three of five naked-eye planets will join our satellite in the sky, and the moon will make a close pass to Saturn, the ringed planet.
On June 27, New Yorkers will see the moon rise at 8:05 p.m. local time, 26 minutes before sunset, according to timeanddate.com. Rising in the east-southeast, the moon is followed just 14 minutes later by Saturn, which reaches opposition — the point at which the planet is exactly opposite the sun as viewed from Earth — at 9:15 a.m. local time. This also happens to be when Saturn is closer to Earth than at any other time during the year.
The full moon will appear (for Northern Hemisphere viewers) to be right above Saturn, and the two objects will get close to one another, within 1.75 degrees, or about three and a half lunar diameters. The moon and Saturn will be in conjunction — having the same celestial longitude — at about 11:23 p.m. New York City time. [Stargazing Maps: Best Night Sky Events of June 2018]
Saturn is also in the middle of its retrograde motion at the time of conjunction and opposition. Retrograde motion means the planet appears to move "backward," east to west, against the background stars as opposed to west to east. This happens because the Earth "catches up" with Saturn in its orbit around the sun just under once a year. So, from our perspective, Saturn appears to move backward for almost five months as it trails behind the Earth. In September, the retrograde motion will end, and Saturn will resume its forward course.
The retrograde motion of planets is itself famous, as the 16th century astronomers Johannes Kepler and Nicholas Copernicus explained it by positing that the Earth was moving around the sun. Previously, astronomers had explained the phenomenon using the Greek astronomer Ptolemy's system of epicycles, which assumed planets all moved around a centrally located Earth.
In addition to making a conjunction with Saturn, the full moon will also be visible at the same time as Mercury, which shines brightly at magnitude -0.1 but is usually quite hard to spot due to its proximity to the sun. Mercury will be easier to see near the end of June, according to heavens-above.com.
From New York City, will Mercury set at 9:56 p.m. local time, and at about 8:45 p.m. — 14 minutes after sunset — it will be about 12 degrees (a bit more than the width of a fist held at arm's length) above the western horizon, below Venus. Near a relatively obstruction-free and flat horizon, a keen-eyed observer should be able to spot the planet. Seeing the innermost planet earlier in the evening is certainly possible, but safety precautions must be taken when looking toward the sun. Mercury will reach its greatest eastern elongation, or farthest apparent distance east of the sun, on July 12.
Venus, meanwhile, will set less than an hour after Mercury, and the "evening star" will be so bright that even just after sunset, you will be able to see it against a still-bluish sky. You can even use it to find Mercury; if you trace an imaginary line from Venus to the sun, that line will cross Mercury.
Jupiter, meanwhile, will reach its highest point at about 9:12 p.m. on the evening of the Strawberry Moon (June 28), and the giant gas planet will be visible for the first half of the night, before setting at 2:23 a.m. local time in New York, while the moon is still relatively high.
As the other naked-eye planets leave, Mars, the god of war, makes an entrance, rising at about 10:43 p.m. local time in New York on June 28. Situated in the constellation Capricorn, Mars will look prominent because of its distinctive red hue and Capricorn's relatively faint complement of stars.
For Southern Hemisphere skywatchers, the conjunction of Saturn and the moon will look rather different. From New York City, the ringed planet will appear "below" the moon, but from Sydney, Australia, or Buenos Aires, Argentina, Saturn will be above the moon. So, if you are looking for the conjunction from anywhere south of the equator, you will see the same conjunction, but in a reversed perspective. The moon and Saturn will also be much higher in the sky, and out longer, because the Austral winter means that the days are shorter and the nights longer.
The traditional names for the full moon of June reflect the environments in which ancient (or not-so-ancient) people lived. The Old Farmer's Almanac calls this moon the Strawberry Moon, as many peoples in the Algonquin language family, such as the Ojibwe, noted that strawberries (one variety of which is native to North America) started ripening at that time of year. But that association wasn't universal; according to the Ontario Native Literacy Coalition, the Cree in Montana and Canada called this moon the Egg-Laying Moon, as some birds started laying eggs in early summer.
Chinese lunar calendars say June's full moon falls in the fifth month, called Púyuè, or the Sweet Sedge Month, according to the tourism website China Highlights. In the middle part of the month, the annual Dragon Boat Festival occurs. This year it falls on June 16-18, China's Xinhuanet news service reports.
Jewish and Muslim lunar calendars both begin their months near the time of the new moon. June 2018's full moon falls in the middle of the Hebrew month of Tammuz. Muslims will be in the middle of Shawwal, the month following Ramadan (which ends on June 15).
In the Southern Hemisphere, names for full moons were associated with the coming of winter rather than summer, and in some cultures, the nights had specific names. The Māori, for example, called the night of the full moon Rākaunui and thought that fishing for eels was not productive on such nights (eels tend to avoid light, and other fish can see them in bright moonlight, so the eels don't come out to hunt during the full moon). The June lunar month of Hongonui is described with the sentence, "Man is now extremely cold and kindles fires before which he basks," according to the Encyclopedia of New Zealand.