How do Rockets Work? A rocket or space shuttle moves forward when gases shooting out the back of the rocket/space shuttle push it in the opposite direction.

What are artificial satellites? What are they used for?

What are space stations? What are they used for? Large artificial satellites on which people can live and work for long periods. Used to conduct long-term observations and experiments in space.

The Moon The Moon does not make its own light. We see it the same way we see mountains in the daylight. The moon’s surface reflects sunlight. Temp: 130°C in direct sunlight -180°C at night

How does the amount of gravity on the moon compare to the amount of gravity on Earth? 1/6 that of Earth’s gravity. Mass is the same on earth and moon, but we weigh less on the moon

How was the moon formed? A planet-sized object collided with Earth debris from collision formed moon.

Explain each of the moon’s surface features. Craters: large round pits Highlands: Light colored features on moons surface were mountains. Maria: Hardened rock formed from huge lava flows.

What is so special about the amount of gravity that the sun has? Gravitational force of the sun is strong enough to hold all of the planets and many other distant objects in orbit.

What is the sun’s interior like? Giant furnace. Sun’s energy from nuclear fusion Hydrogen atoms fuse together to form helium

Explain the 3 layer’s of the sun’s atmosphere. Core: Center of the sun- where sun’s energy is produced Radiation zone: Middle layer -very dense Convection zone: outer layer - hot gases rise from the bottom.

What are: Sunspots and prominences? Sunspots: areas of gas on the sun’s surface that is cooler than the gas around it Prominence: huge reddish loops of gas

Astronomical Unit (AU) = average distance from Earth to the Sun …so earth to sun is 1 AU 1AU = 150 million kilometers Used to measure distance between the Sun and all planets and other stars What is an Astronomical Unit? (AU)

Why are the four inner planets called the terrestrial planets? Small, dense, and have rocky surfaces.

Mercury Smallest Planet not much larger than the moon Virtually no atmosphere Side facing sun 430°C and -170°C on the other side

Venus Size: Earth’s twin-similar in size and mass to earth Atmosphere: thick and always cloudy-sulfuric acid Interesting Rotation:7.5 Earth Months to revolve around the sun and 8 months to rotate on its axis

Earth Size: Largest of the inner planets Atmosphere: 20% is oxygen; rest is nitrogen with small amounts of argon & CO 2 Only Place with Living things that we know of. 70% is covered by H 2 0 Rotation: 1Day Revolution: 1 year

Mars Size: Bigger than Mercury Atmosphere: 95% CO 2 Red planet: Breakdown of iron-rich rocks- creates a rusty dust over the surface Seasons: Mars has seasons because it tilts on its axis like Earth.

Why are the first four outer planets called gas giants? Much larger than Earth Don’t have a solid surface

Jupiter Size: Most massive Atmosphere: Thick made up of hydrogen and helium Red Spot: Giant area of swirling clouds many times bigger than Earth Moons 63

Saturn Size: 2nd largest planet Atmosphere: Thick-mostly of hydrogen and helium Rings: Chunks of ice and rocks orbiting Saturn

Uranus Size: 4x Earth; much smaller than Jupiter or Saturn Rotation: Top to bottom instead of side to side. –hit by an object

Neptune Atmosphere: Contains visible clouds of methane gas Great Dark Spot: giant storm Orbit: 20 years out of 248 years-Pluto and Neptune change orbits

Pluto Size: Less than 2/3 that of Earth Atmosphere: Rocky cold surface with frozen methane, nitrogen, and CO2 Orbit: Takes 248 years; not exactly round, so changes places with Neptune for 20 years Scientists changed the definition of a planet and because of Pluto’s size and orbit it didn’t fit in

Comet Chunks of ice and dust whose orbits are usually very long, narrow ellipses. Nickname: dirty snowball Famous comet: Haley's Comet Orbit the sun and can be seen for days, weeks or months

Asteroid Objects (rocks) too small and numerous to be planets Most are found revolving around the sun between Mars and Jupiter-asteroid belt

Meteoroid, meteor, meteorite Meteoroid: chunk of rock or dust in space Meteor: When meteoroid enters the Earth’s atmosphere(shooting stars) Meteorites: Meteoroids pass through the Earth’s atmosphere and hit the Earth’s surface

Galaxy Giant cluster of stars, gases, and dust held together by gravity Milky Way: where our solar system is located Billions of galaxies in our universe

3 Types of Galaxies Spiral Elliptical Irregular

Main Characteristics to Classify Stars Color: Red, red-orange, yellow, white, and blue or blue-white Temperature: red = 3,200°C, yellow = 5,000°C; white = 8,000°C, blue > 20,000°C Size: Supergiant, Giant, medium-sized, white dwarf, and neutron

Brightness of Stars Apparent magnitude: brightness as seen from Earth Absolute magnitude: brightness a star would have if it were a standard distance from Earth

Hertzsprung-Russell Diagram Graph with temperatures of stars on x-axis and brightness on y- axis Main sequence: surface temperatures ↑ as brightness ↑

How Long Do Stars Live? Small stars with less mass live longer as they use their fuel slowly Medium sized stars like the sun live for about 10 billion years. Sun is estimated to be 4.6 billion years old.

When Stars Die! White Dwarf Neutron Black Hole

Spectrograph A device that breaks light into colors and produces an image of the resulting spectrum Determines how much of each element is in a star Found in large telescopes

Light Year Used to calculate distances between stars or galaxies It is the distance light travels in one year = 9.5 million million kilometers

Light Stars are the source of light for all bright objects in space and that the Moon and planets shine by reflection of the sun’s light