Understanding Day and Night Cycles

Earth's Rotation and Orbit

• The Earth rotates on its axis once every 24 hours, which is equivalent to one day.
• The Earth orbits around the Sun once every 365.25 days, which is equivalent to one year.
• The extra 0.25 days is accounted for every four years in a leap year, where February has 29 days instead of 28.

Day and Night

• The side of the Earth that faces the Sun experiences daylight, while the side that does not face the Sun experiences nighttime.
• Daytime begins at sunrise and ends at sunset, which corresponds to the Earth rotating towards and away from the Sun.
• However, due to the Earth's tilt on its axis (23.5°), some parts of the world experience constant daylight or darkness during certain times of the year.

Equinox and Solstice

• An equinox occurs when the plane of the Earth's Equator passes through the center of the Sun, resulting in day and night being equal in length.
• A solstice occurs when the Sun is at its highest or lowest point in the sky, resulting in the longest or shortest day of the year.
• The solstices mark the beginning of summer or winter, and the Sun appears to stand still in the sky before changing direction.

Moon's Orbit and Rotation

• The Moon orbits around the Earth once every 27.3 days, which is equivalent to a lunar month.
• The Moon also takes 27.3 days to rotate on its own axis, which is why we only see one side of the Moon.
• The other side of the Moon is called the "dark side of the Moon".

Lunar Phases and Eclipses

• The Moon's orbit is tilted 5° relative to the Earth's orbit around the Sun, which is why we don't experience a Solar or Lunar Eclipse every new or full Moon.
• The Moon is always half-illuminated, but the amount of illumination we see depends on the Moon's position relative to the Earth and Sun.
• The phases of the Moon, including waxing, waning, gibbous, and crescent, are determined by the Moon's position relative to the Earth and Sun.
• An eclipse occurs when the Earth, Moon, and Sun are aligned, resulting in a Solar or Lunar Eclipse.