I. Astronomy: The scientific study of matter in I. Astronomy: The scientific study of matter in outer space, especially the positions, dimensions, distribution, motion, composition, energy, and evolution of celestial bodies and phenomena. A. Common objects in our solar system, galaxy and universe

Picture of Milky Way Galaxy - a large group of stars which are formed from spinning clouds of gas. 2. Elliptical Galaxy: -range from ball-shaped to egg-shaped. Contain mostly old stars *most common type of galaxy. Picture of Milky Way Galaxy

Irregular Galaxy: -Galaxy with a non-recognizable shape. Spiral galaxy: -Disk-shaped Barred-spiral Galaxy: -Like spiral galaxies, but the nucleus is elongated into a bar. Irregular Galaxy: -Galaxy with a non-recognizable shape. Spiral Galaxies

3. Comet: -Made of snow, dust, ice and gas. Illuminated (lit up) by Sun. 4. Star: -An enormous, spinning ball of hot and luminous gas (our Sun). 5. Meteor: -Made of dust particles and rock fragments. Does not enter the Earth’s atmosphere. Picture of a Comet

Picture of meteoroid, or shooting star or meteor showers -any of the small bodies, often remnants of comets, traveling through space: it is heated to luminosity and becomes a meteor. 7. Meteorite: -A meteor that survives the atmosphere and hits the Earth’s surface. Picture of meteoroid, or shooting star or meteor showers

Fictional picture of an asteroid hitting the earth, separating Pangaea -A chunk of rock that orbits the sun. Fictional picture of an asteroid hitting the earth, separating Pangaea

Picture of gas clouds and star clusters (Milky Way) -Concentrations of approximately ten thousand to one million stars. Picture of gas clouds and star clusters (Milky Way)

Picture of constellations -88 imagined groupings of bright stars that are named after religious or mythological figures, animals, or objects. Picture of constellations

a. Major constellations 1) Orion 2) Ursa Major (Great Bear) 3) Cygnus 4) Scorpius 5) Cassiopeia

B. Phases of the Moon http://stardate.org/nightsky/moon/ 1. A time when the moon presents a particular recurring appearance. 2. Waxing (crescent/gibbous); Waning (crescent/gibbous); New/Full; First & Third Quarter

C. Eclipses A temporary or permanent dimming or cutting off of light. Umbra: A dark area, especially the blackest part of a shadow from which all light is cut off Penumbra: An outlying surrounding region

D. Tides The periodic variation in the surface level of the oceans caused by gravitational attraction of the moon and sun. The moon, being much nearer to the earth than the sun, is the principal cause of tides. force of gravity decreases with distance two high tides and two low tides occur every day High Tide Low Tide Bay of Fundy

E. Reasons for Seasons 1. The ultimate cause of the seasons is the fact that the Earth's axis is not perpendicular to its orbital plane 2. Earth's axial tilt varies between 21.5° and 24.5° (expressed in terms of the planet's orbital plane)

beginning of the Universe II. Theories on the beginning of the Universe

A. Big Bang: The universe expanded with the explosion of concentrated matter and energy and has been expanding ever since. Cont.

Big Bang Cont. 1. Occurred 15-20 billion years ago. 2. Gravity affected the matter racing outward in all directions. 3. Gravity pulled the matter into clumps, the clumps became galaxies.

Second Theory B. Oscillating Universe: The present expansion will be followed by a concentration, brought on by the force of gravity. Cont.

Oscillating Continued 1. This will happen until the universe goes back to the size of a ball, then it will explode again. 2. This process takes approximately 80 billion years.

Third theory C. Steady State: Theory that states that the universe did not begin with an explosion and will exist at the same size forever. Rejected by most scientists.

III. Planets in our solar system A. Mercury 1. Diameter: 4,880 km 2. Length of days: 59 3. Moons: 0 4. Rings: No

B. Venus 1. Diameter: 12,104 km 2. Length of day: 243 3. Moons: 0 4. Rings: No

2. Length of day: 23 hours, 56 minutes C. Earth 1. Diameter: 12,756 km 2. Length of day: 23 hours, 56 minutes 3. Moons: 1 4. Rings: No

D. Mars 1. Diameter: 6,787 km 2. Length of day: 24 hours 37 min 3. Moons: 2 4. Rings: No Actual Picture of a Martian:

2. Length of day: 9 hours, 55 min. E. Jupiter 1. Diameter: 142,800 km 2. Length of day: 9 hours, 55 min. 3. Moons: 16 4. Rings: Yes

2. Length of day: 10 hours, 42 min. F. Saturn 1. Diameter: 120,600 km 2. Length of day: 10 hours, 42 min. 3. Moons: 17 4. Rings: Yes

2. Length of day: 17 hours, 12 minutes G. Uranus 1. Diameter: 51,300 km 2. Length of day: 17 hours, 12 minutes 3. Moons: 15 4. Rings: Yes

2. Length of day: 16 hours, 6 minutes H. Neptune 1. Diameter: 49,100 km 2. Length of day: 16 hours, 6 minutes 3. Moons: 8 4. Rings: Yes

I. Pluto 1. Diameter: 3,000 km 2. Length of day: 6 hours, 9 min 3. Moons: 1 4. Rings: No