War Mep• What causes day and night?

(Please get this right…)• Do you see different stars at

night here than you do in Oregon? Why or why not?• How Big is the Universe?

Vocabulary• Universe• Galaxy• Solar system• Big Bang Theory• Planet• Dwarf planet• Comet• Asteroid• Meteorites • Sun• Solar Flare• Star • Constellation• Nebula

• Light Year• Black hole• Quasars • Refracting Telescope• Reflecting Telescope• Parallax• Electromagnetic

spectrum• Spectrograph• Parsec• Lunar Eclipse• Solar Eclipse• Globular clusters• Planetary nebulae

Galaxy• A large group of stars, solar systems,

and associated gas and dust in space that is bound by gravity

Solar System• Composed of one or more stars and the

planets and other bodies that orbit around the star(s)

Universe• All of space and everything in it

Big Bang Theory• The universe began with a violent explosion

about 10-15 billion years ago• Since then, the universe has been expanding– We believe it is still expanding!

• Matter in the universe collected to form stars stars died in supernova explosions explosions added new elements to the universe

• About 5 billion years ago, a nebula collapsed to form the solar system

Big Bang Theory• Since the “big bang” created the

entire universe, space and time did not exist before the big bang

• “Space” and “Time” are concepts that came into being when our universe began

How did our Solar System form?• About 5 billion years ago, a nebula collapsed

to form the solar system• Slowly the nebula shrank into a spinning disk• Gravity pulled the matter into the disk’s

center – sun was born• Gas and dust started to collect to form

spheres• Spheres closest to the sun lost most of their

gases and dust/rock collected and became very dense = inner planets (Earth, Mars, etc)

• Spheres farther away retained gases to form gas giant plants = Jupiter, Saturn, etc

Planet• Any celestial body (other than

comets or satellites) that revolves around a star.

Dwarf Planet• A celestial body

orbiting the Sun that is massive enough to be rounded by its own gravity but has not cleared its neighboring region of planetesimals and is not a satellite.

Comet• A small body of ice, rock, and dust that

revolves around a star and forms a tail as it passes close to the star

Halley’s Comet

Asteroid• Small, irregular, rocky objects that

orbit the sun

Meteorites• Pieces of rock (stone or iron) that originate in

space and survive a fall to the ground through Earth's atmosphere

• Most are remnants of asteroids or possibly comets

Planetesimals? Did you just make that up!?!

• Term given to objects in the early solar system that had reached the size of small moons, at which point their gravitational fields were strong enough to begin to influence their neighbors.

Sun• The Sun is a star!• Source of light & heat for the planets in the solar system• Contains 99.85% of the mass in the solar system• the Earth revolves around the Sun

Solar Flare• a sudden eruption of intense high-

energy radiation from the sun's surface

• associated with sunspots and radio interference

Star• a celestial body of hot gases that

radiates energy derived from thermonuclear reactions in the interiorConstellations

• A pattern of stars in the sky

Aries Sagittarius

Nebula• A large amount of gas and dust

spread out in an immense volume

How are stars made?• All stars begin as parts of nebulas • Gravity pulls some of the gas and dust

together– This cloud of dust and gas is called a “photostar”

• When this cloud of dust and gas gets so hot that nuclear fusion occurs…a star is born!– Nuclear fusion – atoms of hydrogen combine to

form helium and lots of energy is released

Light-Year• The distance that light travels in one

year• A measurement of distance, not time!• In space, light travels at a speed of

about 300,000 kilometers per second– 300,000 km = 186,411 miles = over 11,000

football fields!– That’s 11,000 football fields a second!

• In one year, light travels about 9.5 trillion kilometers (about 6 trillion miles)

Black Hole• The remains of an extremely massive

star pulled into a small volume by the force of gravity

Quasar• A distant galaxy with a black hole at

its center

Vocabulary• Refracting

Telescope• Reflecting

Telescope• Parallax• Electromagnetic

spectrum• Spectrograph• Parsec• Lunar Eclipse

• Solar Eclipse• Globular clusters• Planetary

nebulae

Parallax• The apparent change in position of

an object when you look at it from a different places