“It’s the day when the sun takes the longest path from sunrise to sunset across the sky. And that translates into the longest amount of daylight in the Northern Hemisphere.”
Director of the Whitworth Ferguson Planetarium at State University of New York's Buffalo State College, Kevin Williams, explaining the summer solstice. Today marks the first day of summer for Earth's northern half.
jun 21, 2022
- Why It Matters: Today is the "longest day" of the year, and sunlight over the Northern Hemisphere is at its peak intensity "because the sun is at its highest point in the sky then, so its light is hitting Earth’s surface more directly,” said Dr. Williams.
- What is the summer solstice? During the first half of the year in the northern hemisphere, the earth's axis continues to tilt more and more toward the sun. The summer solstice “is the day that the sun stops moving in the northern direction. It holds that position, and then it reverses. It’s one of those moments that triggers you to realize that things are going to start changing seasonally," said Jackie Faherty, an astrophysicist at the American Museum of Natural History in NYC.
- How it originated: Cultures have recognized the summer solstice for thousands of years, closely monitoring the sun's location and its influence on the seasons. Susan Greaney, a historian at English Heritage, explained: "In Northern Europe, midsummer [summer solstice] was celebrated from pre-Christian times until the mid-19th century, with festivals during which bonfires were lit, later incorporated into the Feast of St. John the Baptist."
- Other ancient monuments are tied to the summer solstice. Stonehenge, a prehistoric stone structure in England, dates back about 5,000 years. During the summer solstice, part of the structure specifically "lines up with the rising sun." The longest day of the year is believed to have been celebrated at Stonehenge for thousands of years (National Geographic).
- Summer vs. winter solstice: The only other solstice (which word originates from two Latin words meaning "sun" and "to stand still") occurs in late December each year. The continental U.S. gets between approx. 14 and 16 hours of daylight during the summer solstice and between eight to 10 hours during the winter solstice.
Summer Solstice 2022: What to Know About the Longest Day of the Year (Wall Street Journal)
What is the summer solstice? Here’s what you need to know. (National Geographic)