Which event marks the longest daylight period in the northern hemisphere?

• A. Solstice
• B. Equinox
• C. Eclipse
• D. Aphelion

Answer: (A)

Daylight length in the northern hemisphere is set by the tilt of Earth's axis relative to the Sun. When the northern hemisphere is tilted closest toward the Sun, the Sun climbs higher in the sky and shines over a longer portion of the day. This happens at the summer solstice, around June 21, producing the longest period of daylight of the year. An equinox gives roughly equal day and night, not the longest day. An eclipse is just a temporary alignment that doesn’t change how long the day lasts. Aphelion—the point where Earth is farthest from the Sun—changes distance a bit but not the length of the day. So the longest daylight is at the summer solstice.