A rare confluence of time and space greets the world tonight as June’s full strawberry moon blooms with the summer solstice.
It’s an alignment that hasn’t occurred in nearly 70 years.
At 6:34 p.m., the sun will reach its northernmost point in the sky, shining directly on the Tropic of Cancer and signaling the beginning of astronomical summer in the northern hemisphere.
Less than two hours later, the waxing gibbous moon will swell to full when it rises in the east southeast as the first full moon on the summer solstice since 1948.
June’s full moon is called the strawberry moon because Native American tribes associated it with a time of ripening fruits, according to the Old Farmer’s Almanac.
“The summer solstice is the moment summer begins in the northern hemisphere,” said Sam Storch, a retired astronomy professor and member of the Astronomical Society of the Palm Beaches. “It marks the longest day of the year, the shortest night of the year and the sun having the highest possible altitude for the whole year.”
Slooh.com and the Science Channel will webcast the moon rise live at 8 p.m. from the Canary Islands. Viewers will be able to ask questions of Slooh astronomer Bob Berman and discuss the unusual appearance of the tandem full moon and summer solstice.
“Having a full moon land smack on the solstice is a truly rare event,” said Berman. “By landing exactly on the solstice, this full moon doesn’t just rise as the sun sets, but is opposite the sun in all other ways too.”
Berman said that because the moon will remain low in the sky, which forces its light to be reflected through thicker air, it may actually appear amber-colored.
“This is the true honey moon,” he said, referring to another nickname for June’s full moon.
Seasons are determined by the tilt of the Earth on its axis. During summer, the northern hemisphere tilts toward the sun, meaning its rays are directed nearly straight down instead of at an angle.
While the summer solstice marks the longest day of the year, it is not typically the hottest. It takes the land and atmosphere time to heat up so the warmest temperatures are typically not reflected until weeks later.
“It’s important to mark the summer solstice because it provides a visual, measurable reference point for time before the age where we could just look up everything on the computer,” Storch said. “It means that the days will now get shorter and the nights longer.”