A Mooth of Phases

The moon: it brings us our tides, it glows in weird ways and it changes some people into werewolves. But why does this ball of rock orbiting the Earth "change shape" each night?

In class, we tested this out by making little models of the system of the Sun, the Earth, and the Moon. The Sun was a flash light/UV light, the Earth a Styrofoam sphere and the moon a smaller Styrofoam sphere on a tooth pick. Because Luka (my partner) and I were tired of holding a second Styrofoam ball on a stick, we stabbed the Earth so that when it was upright (well, at a 21.5 degree angle) the moon could appear above the north pole if you looked at it from the side. We then set the Earth on a ruler and held the UV light 30 cm from the Earth. While doing this, we slowly rotated the Earth and observed the moon. We looked at it from above and saw that at each 1/4 or a rotation, it would appear differently. We concluded this is how we see different phases. When the moon is "in between" the Earth and Sun, it would appear as a New moon. On Earth, we would just see (if you could) a dark circle. A quarter way around, we would see the left side of the moon being dark. That phase is called "first quarter". A quarter later, it would be full moon. This is because the moon isn't circling around the equator directly. It's at an angle, there fore the sun hits the side of the moon we're looking at directly. Another quarter and its now vise-verse of the first quarter, and the right side's in the dark. The next quarter? It's the New Moon again! The entire cycle takes 29 days and 11 hours. The cycle itself is called a Lunar Month.

However, sometimes the moon does a weird thing. It passes directly/indirectly between the Sun and Earth. This causes it to make a wonderful phenomenon known as a solar eclipse. A solar eclipse appears as if the moon was eating the sun in the sky, when really the moon is just between the Earth and the direct rays of the sun. Being the range of emotions it is, this has caused many cultures of the past to ask why and make stories, which has caused actions of history. In ancient China whenever there was an eclipse all the Chinese soldiers would fire flaming arrows towards the sun to relight it. An eclipse even post-phoned a war because both armies thought that fighting would anger the sun god and so they decided to let him "cool off" (heh heh). Even though eclipses are cool, you should NEVER look at them directly. Even though most of the sun has been blocked out, you still see the edges and that's DANGEROUS to look at, even with sunglasses. Best to wear solar eclipse glasses ESPECIALLY MADE FOR THE OCCASION. Now, you may be wondering "if it goes directly/indirectly between the sun on one side, does it do the same on the other and what does it look like?" Well those are called lunar eclipses. They basically look as if the Earth had thrown red watercolor paint at the moon and had a laughing fit with it (search it up in Google images if you want to know specifically). The reason it's red is because the Sun gives off reddish light, and when the light bends around the Earth it throws red color the most (and because the sun is mainly red in color). Thankfully these are safe to look at without damaging your eyes. They are also a lot more common than the Solar type.

Where does the moon get it's light?

Believe it or not, the moon gets its light from the sun. It simply reflects the suns rays, and that's how we see it each night. However, because it orbits, we see the suns rays hit the moon from various perspectives. When the moon is in between the sun and the earth indirectly, that's when we get a moonless night, or a "new moon". When it is on the other side, however, the sun hits it directly with no obstacles in its way and we get an "old moon". The transitions between these two major phases create the effect of appearing to disappear or grow because we only see that fraction of the suns rays.

Now, to listen to some music...

http://www.youtube.com/watch?v=FhFbFFwDQiY

Reasons for The Seasons

We love our boiling summers and our freezing winters, our defrosting springs and wet falls, but what causes these seasons?

Around 7 billion years ago, a large, Mars sized planet hit the new-born Earth with the power to knock it of its original axis. Now the Earth turns on a 23.5 degree angle. To be honest, we should be thankful for the hit, or else we would have a rainy season and a dry season. But how does getting hit with a large rock affect our Earth's systems?
During the summer (northern hemisphere) the axis of the Earth and the rotation around the sun, causes the northern hemisphere to lean closer to the sun. Likewise, when the Earth's axis and rotation causes the northern hemisphere to tilt further away from the sun, it becomes winter. This is because when it does tilt away, less sun hits the northern hemisphere directly. Same thing goes for when its summer, except its vise-versa. In the summer, more sun hits the northern hemisphere directly. This causes the seasons.

How did we find this out?
In science class we made a model of the system of the Sun and Earth, the Sun being a UV light while the Earth was a tennis-ball sized Styrofoam ball on a BBQ stick. We  proceeded by placing the Earth 30 cm away from the UV light. We then placed a see-through grid between the Earth and the light. Why the grid? To show how direct the light was hitting the Earth. The more curved the shadow of the grid lines on the sphere, the less direct the sunlight was. We then tilted the Earth at a 23.5 degree angle because of the asteroid and everything. Now you're probably thinking "Alex, how can you tell if the sphere is tilted when it doesn't have a side?" Well, we drew a line around the sphere representing the equator, and thus made a landmark to get an angle. We then proceeded with observations. We found that the light hit the Earth directly near the Equator no matter where the Earth was as it revolved around the Sun. However, the light didn't hit the Northern Hemisphere as direct when the Earth was leaning away from the sun; but the Southern Hemisphere was basking in the sun. On the other side, when the Northern Hemisphere was leaning towards the sun, the light was more direct. We then concluded that summer was when the Northern Hemisphere was leaning towards the sun and light hit it more direct. Winter was the opposite, when the light was less direct. Between was the spring and fall. When the sun hits the Northern Hemisphere the most/least, we get summer/winter solstice. When it's exactly in between the two solstices, it's known as an Equinox.

So next time your'e enjoying the summer weather or making snow angels, thank the large rock for hitting the Earth around 7 billion years ago.