Image From: Astronomy Notes Part 1

Size of the planets compared to the Sun Scale model !

The Inner Planets and our moon (The Terrestrial Planets) Scale model !

The Outer Planets compared to the Inner Planets (The Gas Giants) Scale model ! Click:

Stars An object made of gas that gives off energy –mainly hydrogen –helium The Sun medium in size & life span compared to other stars primary energy source for all processes on Earth much closer to Earth than any other star! about 4 ½ billion years old 1 of 11

H-R Diagram: Shows the relationship between color, temperature, magnitude & size of stars. Color = temperature Magnitude = how bright Our Sun is a main sequence star. Click for Life Cycle of Stars BrainPOP: 2 of 11 Magnitude Click for Life Cycle of Stars Animation:

Nebula Black Dwarf 1. Large cloud of gas & dust where stars form. 3. Expands Explodes! 5. Collapses to just its core 4. Outer layers come off or Iike our Sun! 3 of Gravity pulls material into a sphere that becomes dense, hot & ignites.

Galaxy A large grouping of stars in space. 3 types 1.Spiral – bulge in center & distinctive spiral arms Example: Our galaxy, The Milky Way Our solar system is located within an arm 2.Elliptical – spherical or elongated 3.Irregular of 11

Our Solar System Terrestrial Planet: a rocky, INNER planet Mercury closest to the sun no atmosphere full of craters very hot during day; freezing cold at night Venus Similar in size to Earth Hot, thick & poisonous atmosphere Earth – home! Mars known as the “red planet” because of its iron- rich soil 5 of 11

Gas Giant: large, OUTER planet that is made mostly of gases Jupiter largest planet known for its storm, “The Great Red Spot” Saturn known for its ring system Uranus known for blue-green atmosphere Neptune blue-green atmosphere like Uranus Also has a storm, “The Great Dark Spot” 6 of 11

Moon Image From: Definition: A natural satellite of a planet. The outer planets have many of them! 7 of 11

Other Rocky Bodies... Asteroids asteroid belt between Mars & Jupiter small, rocky body that revolves around the Sun Meteoroids – in space (like asteroids), but usually smaller Meteors – (meteor shower); a bright streak of light caused by the rock burning as it streaks through the atmosphere Meteorites – piece of rock that has landed on Earth without completely burning up, possibly making a crater Comet – a body of ice, rock and dust that forms a tail as it gets close to the Sun 8 of 11

Light Year A measure of how long it takes light to travel through space in one year. Image From: Definition: 9 of 11

Electromagnetic Spectrum The range of all the waves that can travel through matter as well as empty space. Image From : Definition: ROYGBI V 10 of 11 Scientists use different portions of the spectrum to learn about the universe. Ex: light waves can tell us what elements stars are made & if they are moving away or towards other objects.

Theories on the Origin of the Universe 1.Steady State – has always been the same 2.Oscillating Model - began by expanding, has slowed down & is now contracting 3.Big Bang - *the dominant theory 12 to 15 billion years ago Universe began as a dense point that exploded It rapidly expanded & began to cool down, forming stars, etc. Evidence  discovery of cosmic background radiation  red shift in EM spectrum suggest it is still expanding 11 of 11 Click for Big Bang BrainPOP:

Astronomy Notes Part 2

Lunar Cycle

Full moon: all of surface facing Earth is illuminated (= lit ) by the Sun New moon: moon is between Earth & Sun, so lit portion is facing away from Earth Waxing moon: lit portion “growing” Waning moon: lit portion “decreasing” Gibbous moon: larger than ½ Crescent moon: smaller than ½

Can you I.D. these phases? - Where is the sun in this diagram?

Rotation vs. Revolution

Rotation: spin of object on its axis rotates counter-clockwise = west to east = why sun appears to rise in the east and set in the west for Earth = 24 hrs. =1 day responsible for day vs. night Revolution: also called an orbit path of one object around another Earth around sun ≈ 365 days = 1 year moon around Earth ≈ 1 month

The TILT is the reason for seasons! The Earth is tilted on its axis by 23.5.° As a result, the hemisphere that is tilted toward the sun receives more direct sunlight = more heat. causes longer daylight hours hotter temperatures = summer! The hemisphere tilted away from the sun experiences winter.

For the Northern Hemisphere! = Equal hours of day and night = most daylight hours = least daylight hours

Tides Tide = daily rise & fall in ocean water level high and low tides occur twice daily high tides are caused by the gravitational pull of the moon & sun, causing the ocean water to “bulge” away from the Earth the moon has a greater impact because it is closer High tide occurs on the side facing the moon, but it also occurs on the opposite side. This is because the moon is also pulling the Earth away from the water on the other side.

Low Tide High Tide Low Tide High Tide Gravitational pull of the moon Tidal bulge

moon and sun pull together = largest tides moon and sun pull against each other = weakest tides