After the Test 1)Read page 70, then pp and take notes. 2) Select one of the planets, (not Earth) or a moon of a planet and research the following length of night and daytime the temperatures during the day and night, any weather, clouds, seasons (what’s the planets tilt)? the length of a year. Surface color, terrain to stand on, solid, liquid, or gas? How would the sky appear? Would there be a sunrise and sunset – what would it look like? Is there a moon(s). Is there an atmosphere, can you see any stars in the night sky? How much would you weigh –due to the planets gravity?

Nebular Hypothesis of the Formation of the Solar System )

Nebular Hypothesis of the Origin of the Solar System Read pg. 70 Earth Science book (page 161 in Astronomy book) and briefly describe each diagram.

Step 1. About 5 billion years ago Nebulae of gas (hydrogen and helium) and dust a light year across. Due to a nearby supernova explosion (?) it begins to contract As it contracts, it spins faster. Flattens into a disk shape

Step 2: The center contracts and heats up forming a proto-star Sorting: Heavier material (rock an metal) gravitate toward the center. Lighter gas and dust get blown farther out

Step 3: Repeated collisions caused the smaller pieces of material to collide and condense (combine) to form larger bodies. The Sun formed at the center

Step 4: Within a few million years these bodies cooled, cleared their neighborhood and formed into the planets, asteroid belt etc.

The Inner and Outer Planets Planets separated and formed into two broad categories Terrestrial: four planets closest to the Sun; rocky Jovian: farthest from the Sun; gaseous Pluto is more of a rogue moon than anything else.

Inner planets vs Outer planets TerrestrialialJoviann Sections 27.1 and 27.2 on pages

The INNER Planets PG What they have in common: close proximity to the Sun, relatively closely spaced orbits small masses small radii high density Rotate more slowly than Jovian planets posses weak magnetic fields have few or no moons.

The OUTER Planets pg What they have in common: far from the Sun, widely spaced orbits. massive planets Large radii (size) Low density predominantly gaseous no solid surface rotate fast possess strong magnetic fields orbited by many moons. - -

Bellwork: True/False 1. The largest planets have the largest density. 2. The jovian planets rotate faster than earth. 3. All Inner and outer planets have moons. 4. The terrestrial planets are gaseous. 5. The jovian planets are more closely spaced. 6. The jovian planets have rings.