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Earth's Rotation — Reading Comprehension

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MS-ESS1-1

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This middle school science passage, aligned with NGSS standard MS-ESS1-1, focuses on Earth's rotation—how Earth spins on its tilted axis, the mechanisms driving the cycle of day and night, and the observable effects on our daily lives. Students will learn the difference between a sidereal and solar day, the concept of an axis, and how Earth's constant, counterclockwise rotation is proven through scientific evidence like the Foucault pendulum and the Coriolis effect. The passage integrates academic vocabulary and demonstrates the interconnectedness of Earth's rotation with natural phenomena, while also exploring how Earth's rotation is gradually slowing due to tidal friction with the Moon. With audio integration, a differentiated version for struggling readers, and Spanish translations, this resource supports diverse learners and reinforces key science concepts through interactive quizzes, writing activities, and graphic organizers.

CONTENT PREVIEW

Day and Night: Earth's Rotation Explained — Earth's Rotation

Earth’s rotation is the fundamental process that causes the cycle of day and night on our planet. Each day, Earth spins once around its axis—an imaginary line running from the North Pole to the South Pole. This spinning motion not only explains why we experience daylight and darkness but also influences how we observe the movement of the Sun, Moon, and stars across the sky. Understanding Earth’s rotation is essential for explaining many natural patterns we see every day.

How Earth Rotates

Earth completes one full rotation every 23 hours, 56 minutes, and 4 seconds—a period known as a sidereal day. However, our clocks use the 24-hour solar day, which is slightly longer due to Earth’s simultaneous orbit around the Sun. The axis is tilted 23.5° from being perpendicular to the orbital plane, which affects the length of days and seasons. Viewed from above the North Pole, Earth rotates in a counterclockwise direction, meaning it spins from west to east. This is why the Sun appears to rise in the east and set in the west. The side of Earth facing the Sun experiences day, while the opposite side is in darkness, creating night.

Observable Effects and Scientific Evidence

Earth’s rotation causes several observable phenomena. The most obvious is the regular change between day and night. It also makes the Sun and stars appear to move across the sky. However, we do not feel Earth spinning because its rotation is constant and smooth, and the atmosphere moves with the planet. Scientists have proven Earth’s rotation through experiments such as the Foucault pendulum, which swings in a fixed plane while Earth rotates beneath it. Another effect is the Coriolis effect, where moving air and water are deflected due to the planet’s rotation. Long-exposure photographs of the night sky also reveal star trails, showing circular paths caused by Earth’s spin.

Long-Term Changes and Broader Implications

Earth’s rotation is gradually slowing down. This happens because of tidal friction caused by the gravitational pull of the Moon, which acts like a brake. As a result, the length of a day increases by about two milliseconds per century. Billions of years ago, days on Earth were much shorter. Understanding Earth’s rotation helps scientists predict weather patterns, launch satellites, and study climate change. It also connects to larger scientific principles, showing how motion and forces interact in our solar system and affect life on our planet.

Interesting Fact:
About 600 million years ago, a day on Earth lasted only about 21 hours!

What is the main reason Earth experiences day and night?

Earth’s rotation on its axisEarth’s revolution around the SunThe Moon’s orbit around EarthChanges in the atmosphere

How long does one full sidereal day last on Earth?

24 hours exactly23 hours, 56 minutes, and 4 seconds12 hours365 days

What causes the Sun to appear to rise in the east and set in the west?

Earth’s counterclockwise rotation from west to eastThe Moon blocking the SunThe Sun moving around EarthEarth’s axis being perpendicular

Which device demonstrates Earth's rotation by swinging in a fixed plane?

Foucault pendulumBarometerThermometerCompass

What is the Coriolis effect?

The deflection of moving air and water due to Earth’s rotationThe slowing of Earth’s rotation by the MoonThe movement of stars in the skyThe change from day to night

What does tidal friction do to Earth's rotation over time?

Speeds it upStops it completelyGradually slows it downHas no effect

In the passage, what are star trails?

Circular patterns made by stars in photos due to Earth’s spinMeteor showersComet pathsCloud formations

Which of the following is true about Earth's axis?

It is tilted 23.5° from perpendicular to the orbital planeIt is not tilted at allIt points directly at the SunIt causes earthquakes

True or False: We feel Earth’s rotation because it is very fast and bumpy.

TrueFalse

True or False: The length of a day on Earth has always been exactly 24 hours.

TrueFalse