EVERYDAY SCIENCE

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SCIENCE

EARTH SCIENCE

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
During the year, the angle at which the path of the Sun appears in the sky varies. In the Northern Hemisphere, the path of the Sun appears higher on the horizon during the summer and lower on the horizon during the winter. Which factor MOST contributes to the variation in the path of the Sun across the sky?
A
the rotation of Earth
B
the tilted axis of Earth
C
the flattening of Earth at the poles
D
the elliptical shape of the orbit of Earth
Explanation: 

Detailed explanation-1: -It is this 23.5° tilt of the Earth’s spin axis with respect to the ecliptic plane which causes the seasons. Each year we see the Sun cross the celestial equator moving northwards on about 21st March. This is the vernal (March) equinox and at this time the Sun, by definition, is at RA = 0h, Dec = 0.0°.

Detailed explanation-2: -In the Northern Hemisphere, north is to the left. The Sun rises in the east (far arrow), culminates in the south (to the right) while moving to the right, and sets in the west (near arrow). Both rise and set positions are displaced towards the north in midsummer and the south in midwinter.

Detailed explanation-3: -The summer solstice occurs at the moment the earth’s tilt toward/from the sun is at a maximum. Therefore, on the day of the summer solstice, the sun appears at its highest elevation with a noontime position that changes very little for several days before and after the summer solstice.

Detailed explanation-4: -The Sun appears higher in the sky during the northern hemisphere summer, moving lower as we move into winter. The larger loop shows how the Sun’s position changes rapidly between measurements. At that time of year the Earth is closer to the Sun and therefore travels faster around it.

There is 1 question to complete.
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