| The sundial above, dated 1509, shows equinoctial hours with a gnomon parallel to the earth's axis. |
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| The gravitational pull of the sun and moon cause a phenomenon known as the precession of the equinoxes, which makes the earth's axis move in a cone shape. |
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| Due to the tilt of the earth's axis, the sun is higher above the horizon in the summer months and lower in the winter months. |
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| The dial plate, with the 15 degree angles marked on it, is parallel to the equator, and the straw forming the gnomon is parallel to the earth's axis. |
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| This force is strongest for a particle at the equator that has a longer path to follow around the earth's axis each day, despite its greater distance from the earth's axis. |
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| At that time, the climate of northern Canada was warmer than at present because the area received more solar energy due to slow changes in the tilt of the earth's axis. |
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| This is the phenomenon of precession, caused by the Earth's axis slowly rotating around the celestial poles. |
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| Polaris, the North Star, appears stationary in the sky because it is positioned close to the line of Earth's axis projected into space. |
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| Aligning the sundial to the Earth's axis of rotation, the Sun's progression through the sky casts shadows which correspond to the time of day. |
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| If you were at the North Pole, you'd spin around but wouldn't go anywhere because the distance from the Earth's axis is zero. |
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| Because of the precession of Earth's axis, the star Thuban was the polestar in the third millennium bce. |
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| The great circle of the celestial sphere perpendicular to an axis close to the Earth's axis of rotation. |
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| This apparent solar path over the year, called the ecliptic, is really to do with the tilt of the Earth's axis. |
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| The axis of this apparent motion coincides with the Earth's axis of rotation. |
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| The closeness of Polaris to Earth's axis of rotation is purely coincidental. |
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| If the Earth's axis were not tilted toward the sun, a vertical rod at the equator would have no shadow. |
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| Relatively small changes in the orientation of the Earth's axis or length of the seasons can be a major influence on the Earth's climate. |
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| Earth's axis of rotation is tilted, producing seasonal variations on the planet's surface. |
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| Earth's axis is inclined at approximately 23 degrees to the Sun's celestial equator changing the altitude of the Sun during the year. |
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| Of particular importance are changes in the tilt of the Earth's axis, which affect the intensity of seasons. |
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| These are the solstices, Sun, the effects of rotation, revolution, and approximately midway between the orientation of the Earth's axis on the path of equinoxes. |
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| The three types of orbital variations are variations in Earth's eccentricity, changes in the tilt angle of Earth's axis of rotation, and precession of Earth's axis. |
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| The third is precession, or wobbling motion of Earth's axis. |
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| The second is a shift in the tilt of the Earth's axis, the obliquity. |
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