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__Seasons, Day & Night __ by Heather Murphy     __Seasons__ We may not realize it, but seasons affect our everday activities. They determine whether we wear shorts or snow pants, shovel the snow, or slather on the sunscreen. But what are seasons really? Take a look, and you shall find out!

As we know it, the sun is the centre of our solar system, not the Earth as was once thought. This understanding was brought to us by Nicolai Copernicus (1473-1543).  Did you know seasons that are actually NOT caused by the earth's distance from the sun? In actual fact, it's the tilt of the earth, and the fact that the earth’s axis is always the same that causes seasonal change. The Earth’s tilt is nearly 23.5˚ (23.45˚ to be exact). If this tilt did not exist, the sun would always be above the equator. Therefore, the Northern and Southern Hemispheres would have a similar temperature for the entire year, which is not the case today. When the North Pole is facing the sun, the Sun is directed towards the Northern Hemisphere, causing summer here in Canada and the rest of the Northern Hemisphere. When the Sun is closer to the South Pole, those in the Southern Hemisphere experience summer.

The beginning of seasons are marked by equinoxes and solstices - terms that relate to the Earth’s tilt.

Solstices occur when one of the poles is as close to the sun as it can be, and the other is as far away as possible. Solstices signify the start of summer, and winter; June 20 or 21 & December 21 or 22. On these days, the lengths of sunshine and darkness have the greatest differences.

The vernal and autumnal equinox signify the beginning of spring, and autumn. At these times, the length of night and day is most equal for much of the planet because the sun is directly over the equator.

So, why does the change in seasons happen, you ask? Well, when it’s summer here, the North Pole is tilted towards the sun. The sun is closer to us, therefore taking less distance to travel. Also, the sun has less area to cover, so there is more radiation directly overhead.  media type="custom" key="3876113"



Here is another really cool video that shows the amount of sunlight each Hemisphere gets depending on the month. Check it out: []

<span style="font-family: Arial, Helvetica, sans-serif; color: navy; font-size: 12pt; msobidifontsize: 15.5pt; msobidifontfamily: Arial;">__Day & Night__ Day and night are two totally different times of the day. One of them most of us are at our peak of energy, working diligently away. At this time of day, the sun is high in the sky. During nighttime, we are curling up under the covers... or so we should be! <span style="font-family: Arial, Helvetica, sans-serif; color: navy; font-size: 12pt; mso-bidi-font-size: 15.5pt; mso-bidi-font-family: Arial; msobidifontsize: 15.5pt; msobidifontfamily: Arial;">

<span style="font-family: Arial, Helvetica, sans-serif; color: navy; font-size: 12pt; msobidifontsize: 15.5pt; msobidifontfamily: Arial;">But what causes day and night? Well, as you know, on the planet Earth, 1 day is equal to 24 hours. The length of daylight, however, depends on the season it is (see above). The Earth spins on its axis, and this is what causes day and night. Essentially, the ‘axis’ is an imaginary line that passes through the North and South poles. The Earth takes one full day to complete its rotation. Only one side of the Earth is facing the sun at a time. This is why when it is daytime here, it is night on the other side of the world, and vise versa. As you may or may not know, the sun rises in the East, and sets in the West. This occurs because the Earth is moving towards the east in its orbit.

So, in conclusion to the big question, does the Earth revolve around the Sun, the answer is yes. The Earth revolves around on it's own axis, as well as orbits the sun. We orbit the sun at 365.25 days. In 1 "year" there are usually 365 days, but we add the extra day every 4th year, commonly known as the leap year, so that we don't just discard the .25 of a day. Eventually, all those days would add up, and it really would end up snowing in July!