Process

**Background Information **
The Sun is the star at the center of our Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields. It has a diameter of about 1,392,000 km, about 109 times that of Earth, and its mass is about 2×10
 * 30 **kilograms, 330,000 times that of Earth. This mass accounts for about 99.86% of the total mass of our Solar System. Chemically, about three quarters of the Sun's mass consists of hydrogen while the rest is mostly helium. The Sun is the closest star to Earth, causing it to look bigger and brighter than any other star.

The mean distance of the Sun from the Earth is approximately 149.6 million kilometers. Light travels from the Sun to Earth in about 8 minutes and 19 seconds. The energy of this sun light supports almost all life on Earth by photosynthesis and drives Earth's climate and weather.

The Moon is Earth's only natural satellite and the fifth largest satellite in the Solar System. The Moon’s diameter is about ¼ that of Earth’s and **1⁄81 its mass. The dark, featureless lunar plains, which can clearly be seen with the naked eye are called maria (Latin for "seas"; singular //mare // **) since they were believed by ancient astronomers to be filled with water. They are solidified pools of ancient basaltic lava. The other major geologic process that has affected the Moon's surface is impact cratering, with craters being formed when asteroids and comets collide with the surface. There are estimated to be roughly 300,000 craters wider than 1 km on the Moon's near side alone. The lack of an atmosphere, weather, water, and recent geological processes mean that many of these craters are well-preserved.

Earth is the third planet from the Sun and the fifth-largest of the 8 planets in the Solar System. It is also the largest of the Solar System's 4 terrestrial planets. Earth is currently the only astronomical body where life, including millions of plant and animal species, is known to exist. The Earth’s atmosphere: liquid water, its orbit, as well as the formation of the ozone layer that blocks harmful solar radiation and other physical properties, permits life to exist . The planet's interior remains active. Earth interacts with other objects in space especially the Sun and the Moon.

While researching, you may see numbers like the one written here. This is a way to write numbers that are too big or too small to write normally. The superscript after the 10 indicates the number of places (usually zeros) behind the decimal point. This method is called scientific notation. ||
 * Write this number. 6x10 11 km - 600,000,000,000 km.


 * Good site for metric conversions: **
 * [|www.sciencemadesimple.com/conversions.html] **


 * Exemplar Lesson 2 Resources and Reference:**
 * PowerPoint: Day and Night: [|12_S050702E_Day and Night.ppt]**
 * Resources and References:**


 * World day and night map: []**
 * Earth’s rotation:****[]**
 * Amount of sunlight on Earth from two views: []**


 * Apparent movement of Sun:****[]**