Why Is June 21 the Longest Day of the Year?
Quick Answer
June 21st is the longest day of the year in the Northern Hemisphere because it is the summer solstice, which describes the tilt of the Earth's axis. This phenomenon is only observable outside of the tropics as it is the tilt of the Earth that alters the duration of light exposure of any one point on the surface.
Continue ReadingFull Answer
During the summer, the Northern Hemisphere is pointed directly toward the Sun, which results in more total exposure. Alternatively, the Earth is also at its greatest distance from the Sun, so the energy is diffused over a greater distance, which somewhat reduces the overall effect. The summer solstice in the Northern Hemisphere directly corresponds to the winter solstice in the Southern Hemisphere. During this time, the Southern Hemisphere is pointed away from the sun. During an equinox, the axis of the Earth is perpendicular to the Sun, which results in nearly equal periods of day and night.
It all comes down to the 23.5 degree tilt of the Earth's axis, without which there would be no seasons and seasonal climate changes. This may be part of why the Earth has managed to develop an equilibrium of birth, death and renewal common throughout so much of the planet.
Learn more about AstronomyRelated Questions
-
Q:
What Causes Day and Night to Happen?
A: The Earth goes through a constant cycle of day and night because it rotates on an axis. At any point in time, only about half of the Earth is facing the su... Full Answer >Filed Under: -
Q:
Why Does Temperature Change During the Seasons?
A: Temperature changes throughout the year are caused by the tilt of the Earth on its axis and its revolution around the sun that allows sunlight to strike mo... Full Answer >Filed Under: -
Q:
Where Does the Sun Rise?
A: The sun always rises in the east because of Earth's eastward rotation on its axis. This rotation causes the sun to first be seen on the eastern horizon on ... Full Answer >Filed Under: -
Q:
What Is the Ecliptic, and Why Is It Tilted With Respect to the Celestial Equator?
A: The ecliptic is the course the sun is observed to take from the point of a view of Earth as it appears to revolve around Earth in a line that is inclined w... Full Answer >Filed Under:
