Final answer:
The Earth is tilted at an angle of 23.5°, which, combined with its revolution around the Sun, causes varying lengths of days and seasons. This tilt leads to different hemispheres receiving more direct sunlight at different times of the year, not the distance from the Sun. The angle of Earth's tilt changes only over tens of thousands of years, affecting seasonality.
Step-by-step explanation:
The correct answer to the question about the Earth's tilt is: b) The Earth is tilted 23.5° causing the length of days to change during the Earth's 24-hour rotation.
Earth's 23.5° tilt on its axis is responsible for the changing seasons and the varying lengths of days and nights throughout the year. This tilt, coupled with Earth's revolution around the Sun, results in different parts of Earth receiving varying amounts of sunlight at different times of the year.
For instance, during the summer solstice, the Northern Hemisphere is tilted towards the Sun, resulting in longer days and shorter nights. Conversely, during the winter solstice, the Northern Hemisphere is tilted away from the Sun, leading to shorter days and longer nights. At the equinoxes, both hemispheres receive roughly equal sunlight, leading to approximately 12 hours of daylight and 12 hours of darkness.
It is a common misconception that the distance between Earth and the Sun is the main cause for the seasons, but in reality, the Earth's orbit around the Sun sees a minimal change of only about 3%, which is not sufficient to cause the observed variations in temperature and climate. This misunderstanding is further complicated by the fact that the Earth is actually closest to the Sun in January, during the Northern Hemisphere's winter, and furthest away in July, during its summer.
The angle of Earth's tilt only changes over very long periods, in a cycle known as obliquity, which occurs over roughly 41,000 years, varying between 22.1 and 24.5 degrees. These minor changes can augment or moderate the seasons over very long timescales.