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1. They both involve spinning for differennt purposes.
2. They both allow change to happen so we can be on a livable planet.

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Difference between rotation and revolution

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So far, we have discussed the importance of the Earth's rotation on its axis. But what about the Earth's movement as it orbits the Sun? We refer to this motion as the Earth's revolution around the Sun. The Earth takes 365.242 days to travel around the Sun-almost a quarter of a day longer than the calendar year of 365 days. Every four years, this time adds up to nearly one extra day, which we account for by inserting a 29th day into February in leap years. Further minor corrections-such as omitting the extra day in century years-are necessary to keep the calendar on track.

The Earth's orbit around the Sun is shaped like an ellipse, or oval (Figure 1.17 ). This means that the distance between the Earth and Sun varies somewhat through the year. The Earth is nearest to the Sun at perihelion , which occurs on or near January 3. It is farthest away from the Sun at aphelion , on or near July 4. However, the distance between Sun and Earth varies only by about 3 percent during one revolution because the elliptical orbit is shaped very much like a circle. For most purposes we can regard the orbit as circular. Which way does the Earth revolve? Imagine yourself in space, looking down on the North Pole. From this viewpoint, the Earth travels counterclockwise around the Sun (Figure 1.18 ). This is the same direction as the Earth's rotation.

MOTIONS OF THE MOON

The Moon rotates on its axis and revolves about the Earth in the same direction as the Earth rotates and revolves around the Sun. But the Moon's rate of rotation is synchronized with the Earth's rotation so that one side of the Moon is permanently directed toward the Earth while the opposite side of the Moon remains hidden. It was only when a Soviet spacecraft passing the Moon transmitted photos back to Earth in 1959 that we caught our first glimpse of the far side.

The phases of the Moon are determined by the position of the Moon in its orbit around the Earth, which in turn determines how much of the sunlit Moon is seen from the Earth. It takes about 29.5 days for the Moon to go from one full Moon to the next. In the twilight photo of a moonlit scene in Figure 1.19 , the Moon is nearly full. From the way that the Sun illuminates the Moon as a sphere, it is easy to see that the Sun is down and to the right.

TILT OF THE EARTH'S AXIS

Depending on where you live in the world, the effects of the changing seasons can be large. But why do we experience seasons on Earth? And why do the hours of daylight change throughout the year-most extremely at the poles, and less so near the Equator? Seasons arise because the Earth's axis is not perpendicular to the plane containing the Earth's orbit around the Sun, which is known as the plane of the ecliptic. Figure 1.20 shows this plane as it intersects the Earth.

If we extend the imaginary axis out of the North Pole into space, it always aims toward Polaris, the North Star. The direction of the axis does not change as the Earth revolves around the Sun. Let's investigate this phenomenon in more detail.

THE FOUR SEASONS

Figure 1.21 shows the full Earth orbit traced on the plane of the ecliptic. On December 22, the north polar end of the Earth's axis leans at the maximum angle away from the Sun, 23 ?°. This event is called the December solstice , or winter solstice in the northern hemisphere. At this time, the southern hemisphere is tilted toward the Sun and enjoys strong solar heating.

Six months later, on June 21, the Earth has traveled to the opposite side of its orbit. This is known as the June solstice , or summer solstice in the northern hemisphere. The north polar end of the axis is tilted at 23 ?° toward the Sun, while the South Pole and southern hemisphere are tilted away. The equinoxes occur midway between the solstice dates. At an equinox, the Earth's axis is not tilted toward the Sun or away from it. The March equinox (vernal equinox in the northern hemisphere) occurs near March 21, and the September equinox (autumnal equinox) occurs near September 23. The conditions at the two equinoxes are identical as far as the Earth-Sun relationship is concerned. The date of any solstice or equinox in a particular year may vary by a day or so, since the revolution period is not exactly 365 days.

EQUINOX CONDITIONS

The Sun's rays always divide the Earth into two hemispheres-one that is bathed in light and one that is shrouded in darkness. The circle of illumination is the circle that separates the day hemisphere from the night hemisphere. The subsolar point is the single point on the Earth's surface where the Sun is directly overhead at a particular moment.

At equinox, the circle of illumination passes through the North and South Poles, as we see in Figure 1.22. The Sun's rays graze the surface at both poles, so the surfaces at the poles receive very little solar energy. The subsolar point falls on the Equator. Here, the angle between the Sun's rays and the Earth's surface is 90°, so that point receives the full force of solar illumination. At noon at latitudes in between, such as 40° N, the Sun strikes the surface at an angle that is less than 90°. The angle that marks the Sun's elevation above the horizon is known as the noon angle. Simple geometry shows that for equinox conditions the noon angle is equal to 90° minus the latitude, so that at 40° N, the noon angle is 50°.

One important feature of the equinox is that day and night are of equal length everywhere on the globe. You can see this by imagining yourself located at a point on the 40° N parallel. As the world turns, you will be in daylight for exactly half the day and in night for the other half.

SOLSTICE CONDITIONS

Now let's examine the solstice conditions in Figure 1.23. The June solstice is shown on the left. Imagine that you are back at a point on the lat. 40° N parallel. Unlike at equinox, the circle of illumination no longer divides your parallel into equal halves because of the tilt of the northern hemisphere toward the Sun. Instead, daylight covers most of the parallel, with a smaller amount passing through twilight and darkness. For you, the day is now considerably longer (about 15 hours) than the night (about 9 hours). Now step onto the Equator. You can see that this is the only parallel that is divided exactly into two. On the Equator, daylight and nighttime hours will be equal throughout the year.

The farther north you go, the more the effect increases. Once you move north of lat. 66 ?°, the day con tinues unbroken for 24 hours. Looking at Figure 1.23 , we can see that is because the lat. 66 ?° parallel is positioned entirely within the daylight side of the circle of illumination. This parallel is known as the Arctic Circle. Even though the Earth rotates through a full cycle during a 24-hour period, the area north of the Arctic Circle will remain in continuous daylight. We can also see that the subsolar point is at a latitude of 23 ?° N. This parallel is known as the Tropic of Cancer. Because the Sun is directly over the Tropic of Cancer at this solstice, solar energy is most intense here.

The conditions are reversed at the December solstice. Back at lat. 40° N, the night is about 15 hours long, while daylight lasts about 9 hours. All the area south of lat. 66 ?° S lies under the Sun's rays, inundated with 24 hours of daylight. This parallel is known as the Antarctic Circle. The subsolar point has shifted to a point on the parallel at lat. 23 ?° S, known as the Tropic of Capricorn.

We have carefully used the term daylight to describe the period of the day during which the Sun is above the horizon. When the Sun is not too far below the horizon, the sky is still lit by twilight. At high latitudes during the polar night, twilight can be several hours long and provide enough illumination for many outdoor activities.

The solstices and equinoxes are four special events that occur only once during the year. Between these times, the latitude of the sub solar point travels northward and southward in an annual cycle, looping between the Tropics of Cancer and Capricorn. We call the latitude of the subsolar point the Sun's
declination (Figure 1.24 ). As the seasonal cycle pro gresses, the polar reg ions that are bathed in 24-hour daylight or shadowed in 24-hour night shrink and then grow. At other latitudes, the length of daylight changes slightly from one day to the next, except at the Equator, where it remains the same. In this way, the Earth experiences the rhythm of the seasons as it continues its revolution around the Sun.

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So far, we have discussed the importance of the Earth's rotation on its axis. But what about the Earth's movement as it orbits the Sun? We refer to this motion as the Earth's revolution around the Sun. The Earth takes 365.242 days to travel around the Sun-almost a quarter of a day longer than the calendar year of 365 days.

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A sidereal day is the time it takes for the Earth to rotate about its axis so that the distant stars appear in the same position in the sky. A solar day is the time it takes for the Earth to rotate about its axis so that the Sun appears in the same position in the sky. The sidereal day is ~4 minutes shorter than the solar day

Our planet Earth rotates around its axis from west to east. An axis isÂ an imaginary lineÂ that runs from the North Pole to the South Pole.Â If you look on the Earth from theÂ northern hemisphere,Â it rotates counter clockwise. One complete rotation around its own axis relativeÂ to the SunÂ is called a solar day and has aÂ duration of 24 hours. OurÂ Earth doesnâ€™t rotate just around its own axis,Â but it also orbits in the same direction around the SunÂ andÂ moves a little bit on orbit every day. Therefore the Earth gets in the same position relative to the celestial stars in a shorter time. This is called a sidereal day which has aÂ duration of 23 hours 56 minutes and 4.1 seconds. This is the reason why the stars appear about four minutes earlier in the sky every day. A sidereal day is a period that takes the Earth to rotate around its axis so that the distant stars appear in the same position in the sky.

Our planet rotation

The point at which a planet is closest to the sun is called perihelion. The farthest point is called aphelion.

Earthâ€™s rotation around its axis results in the alternation of day and night. Earth also moves around the Sun on the ecliptic plane in an ellipticalÂ orbit. This movement along with the fact that its axis is tilted to the ecliptic plane is causing the changing of seasons. But Earthâ€™s rotation and speed is even more complex: There is aÂ long term slowing of its rotation due to the tidal forces of the Moon and Sun. As a result of the precessionÂ (a slow movement of an axis of a spinning body around another axis due to a torque such as gravitational influence, casuses a change of direction of the first axis) and nutation (a periodic variation in an inclination of an axis of a rotating object) the change of a rotational axis direction occurs.

We have four seasons

The length of Earthâ€˜s trajectory around the sun is 940 million km. Thus the Earth travels about 107,000 kilometers per hour. This means that our planet moves around the Sun at an average speed of 30 kilometers per second. Earthâ€™s speed is not constant as the Earth orbits elliptical orbit. If the Earth is the closest to the Sun (perihelion), it moves the fastest. On the other hand when the Earth is the farthest from the Sun (aphelion), it moves the slowest.

Over the course of a year the orientation of the axis remains fixed in space, producing changes in the distribution of solar radiation. Â

It takes the planet Earth about 23.9 hours to complete one rotation on its axis. Complete orbit around the Sun takes about 365.26 days. The Earthâ€™s rotation axis is tilted relative to the imaginary space orbit around the Sun.Â This imaginary plane is called the ecliptic plane.Â Position of northern and southern hemisphere toward the Sun varies depending on the season. These movements of the planet change the amount of light that each hemisphere receives, thus causing the changing of seasons. We all know that our calendar has 365 days per standard year. The extra quarter of a day presents a challenge to our calendar system. If we want to keep our annual calendar system consistent with the Earthâ€™s orbitÂ around the Sun,Â then every four years one day is added to the standard year. Such a year is called a leap year and the extra day is called a leap day. So what actually causes our four-year cycle? It isÂ the position ofÂ the Earthâ€™s axis, which is tilted 23.4 degrees relativeÂ to the plane of its orbit around the Sun.Â This tilt causes our yearly cycle of seasons. The Northern hemisphere isÂ tilted towards the Sun one part of a year and during this time the southern hemisphereÂ is diverted. During this time, the solar heating is greater in the north so we have summer there, on the other hand less direct solar heating causes winter seasonÂ in the southernÂ part of our planet. The weather conditions change every six months. There is a position when both hemispheres receive approximately the same amount of heat. It is the time when spring and fall begin on our planet.

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Some characteristics about Earth

Average distance from Sun

149,598,262 km (1.0 AU)

Perihelion (closest distance to the Sun)

147,098,291 km

Aphelion (farthest distance from the Sun)

152,098,233 km

Orbital eccentricity

0.007

Orbital velocity

107,244 km/h

Single period of revolution around the Sun

365.26 Earth days (1.00 year)

Single rotation period on its axis

23.934 h

Equatorial inclination to orbit

23.4393 degrees

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Our planetâ€˜s orbit is not a perfect circle

An orbit is a regular and cyclic path on which an object in space is orbiting another object. Individual objects on orbit are called satellites and may be natural or artificial. Planets and moons are examples of natural satellites. An example of an artificialÂ satellite can beÂ the International Space Station. Our Sun, as the dominant star in the Solar System, is orbited by a number of planets, comets, asteroids and other space objects. Most of these orbiting objects are moving along or near theÂ imaginary flat surface,Â which isÂ called the ecliptic plane.Â An orbit of the planet Earth is not a perfect circle but it rather has a character of an oval-shaped ellipse. The Earth is slightly closer to the SunÂ in early January and farther awayÂ in theÂ month of July. However a much greater effect on the intensity of heating or cooling of our planet has the tiltedÂ axis of the Earth.Â A very important fact is that the Earth is located in the so-called â€œGoldilocks zoneâ€, where a temperature is just acceptable to maintain liquid water on the surface.

And finally a final motion

Our planet Earth, like other planets ofÂ the Solar System,Â has three motions. It spins on its axis, it travels around the Sun, and it movesÂ through the Milky Way GalaxyÂ with the rest of theÂ Solar System.Â The third and final motion of the Earth is along withÂ the Solar SystemÂ around the center of our Milky Way Galaxy. The Sun, along with other stars of our galaxy, revolves around its center. It takesÂ the Solar SystemÂ to orbit the center about 220 million years and it orbits at the speed of about 250 kilometers per second.

Article by: Viliam OruÅ¾inskÃ½, Andrej FaÅ¡ung

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A sidereal day is the time it takes for the Earth to rotate about its axis so that the distant stars appear in the same position in the sky. A solar day is the time it takes for the Earth to rotate about its axis so that the Sun appears in the same position in the sky.

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Study Earth's daily rotation on its axis and yearly revolution around the Sun Encyclopædia Britannica, Inc.

Transcript

NARRATOR: Earth experiences two different motions, rotation and revolution. Earth spins on its axis, and it takes one day to do so. In one day Earth makes one rotation on its axis. Earth also travels on an elliptical orbit around the Sun. And it takes one year to make a complete trip. In one year Earth makes one revolution around the Sun.

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Study Earth's daily rotation on its axis and yearly revolution around the Sun

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NARRATOR: Earth experiences two different motions, rotation and revolution. Earth spins on its axis, and it takes one day to do so. In one day Earth makes one rotation on its axis. Earth also travels on an elliptical orbit around the Sun. And it takes one year to make a complete trip.

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1. Revolution is the planets going around the sun on their own orbit.
2. It takes about up to year
for the earth to fully revolve around the sun.
3. The effect revolution has on the earth is by creating seasons and if we didn't have revolution we'd be stuck with the same season.

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1. Rotation Is the planet spinning on its axis to make a full rotation.
2.  The Earth takes about a day to make a full rotation.
3.The purpose of rotation is to allow us to have day and night.