Science Study Guide - Solar System & Universe PDF

**Study Guide - UNIT TEST: Solar System & The Universe 24-25** SOLAR SYSTEM - **Inner Planets** - **The first four planets closest to the Sun: Mercury, Venus, Earth, and Mars** - **Characteristics:** **Solid rock**; **Also called TERRESTRIAL planets; few moons; shor...

**Study Guide - UNIT TEST: Solar System & The Universe 24-25** SOLAR SYSTEM - **Inner Planets** - **The first four planets closest to the Sun: Mercury, Venus, Earth, and Mars** - **Characteristics:** **Solid rock**; **Also called TERRESTRIAL planets; few moons; short orbit around Sun (closer)** - **Outer Planets** - **The last four planets, farthest from the Sun: Jupiter, Saturn, Uranus, & Neptune** - **Characteristics:** **Hydrogen & helium**; **Ring systems are composed of ice, ice-covered rocks and dust**; **Also called JOVIAN planets; many moons; long orbit around Sun (far away)** - **Planet Trivia + Order** - **[Mercury]**\--**Closest to the Sun; Fastest "Orbital Velocity" (how fast a planet travels around the Sun)** - **[Venus]**\--**2nd planet from the Sun**; **Hottest Planet; known as "Earth's Twin"** - **[Earth]**\--**3rd planet from the Sun; Water occurs as a solid (ice), liquid, or gas (water vapor) due to Earth's position in the Solar System**; **LIFE; Rotation- 1 day (causes day & night---and stars appear to move at night)**; **Revolution- 1 year, (causes the seasons)**; **Axis Tilt = 23.5º** - [**Mars**\--]**4th planet from the Sun**; **Olympus Mons (largest volcano in the solar system)** - [**Asteroid Belt**\--]**Separates the inner planets from the outer planets**; **Composed of small, rocky bodies centered roughly between Mars and Jupiter** - **[Jupiter]**\--**5th planet from the Sun**; **Largest planet**; **Great Red Spot** - [**Saturn**\--]**6th planet from the Sun**; **Largest ring system**; - [**Uranus**\--]**7th planet from the Sun**; **Magnetic field nearly upright (rings are vertical)** - [**Neptune**\--]**8th planet from the Sun**; **Great Dark Spot (Hurricane)** - **[Pluto] (Dwarf Planet)\--not considered a planet anymore)** MINOR OBJECTS - **Moons- natural satellites of planets that vary widely in composition** - **Meteoroids -- small rocky +iron object floating in space** - **Meteor - Flash you see in the sky (shooting star)** - **Meteorite -- object after it hits the Earth** - **Meteor Shower - Caused by comets passing through Earth's orbit** - **Comets - Frozen ammonia, methane, water, chunks of rock & dirt; Comet tails ALWAYS point away from the Sun (because of solar wind)** - **Asteroids - Many orbit between Mars & Jupiter; small rocky objects** SUN - **Layers** *(outside in)* - Corona, Chromosphere, Photosphere (this is the layer we see), Conductive/Radiative Zones, Core (fusion occurs here) - **Nuclear FUSION** - Hydrogen fuses into helium - when two atoms of hydrogen come together to form one atom of helium - Gives stars their light, heat, and energy - **AVERAGE compared to other stars** - Medium sized star - Medium mass star - Medium temperature star - Main sequence yellow star UNIVERSE - **Distance** - **[Light Year] -distance light travel in 1 year (Most commonly used measurement for distance in astronomy -- especially outside of our solar system)** - **Parallax - The apparent displacement of an observed object due to a change in the position of the observer** - **Star Brightness** - **[Luminosity] - brightness of a star compared to the Sun (Sun = 1)** - **[Apparent Magnitude] (m) \-- The brightness of a star as seen from Earth (negative \# = brighter)** - **[Absolute Magnitude] (M) -- Brightness of a star as seen from 32 light years---true brightness** - **Surface Temperatures** - **Hottest are blue in color** - **Coolest are red in color** - **Hertzsprung-Russell Diagram** - **A diagram that shows the relationship between the absolute magnitude of stars to the temperature.** - **Shortened to "HR Diagram"** - **Constellations -- Stars that appear to form a pattern in the night sky (88)** - **Galaxies -- collections of billions of stars** - **[3 Types:]** **Elliptical**, **Spiral**, & **Irregular** - **[Elliptical Galaxies] - Round or oval in shape** - **[Irregular Galaxies]** -- no distinct shape - **[Spiral Galaxies] - pin-wheel shaped, Concentration of stars near the center** - **Milky Way (our galaxy is a spiral galaxy) \--our solar system is here on an arm (not the center)** - **Life Cycle** - **Stars have a finite lifetime and evolve over time.** - **The mass of a star controls its evolution, length of its lifetime, and ultimate fate.** - **Stars form by condensation of interstellar gas.** - **Stages:** - **[Stellar Nebula] - Birthplace of new stars, Cloud of dust & gas** - **[Main Sequence] - Most stars are in this category; Our Sun is in the main sequence** - **[Red Giants] - These stars are very, very large in size.** - **[Supergiants] - These stars are so enormous that the Sun would appear microscopic** - ***For Low Mass Stars:*** - **Dwarfs - Cool and small in size** - ***For High Mass Stars:*** - **Supernova - Explosion of a star** - **Neutron Star- supernova leftovers** - ***For Extremely High Mass Stars:*** - **Supernova - Explosion of a star** - **Black Hole - Nothing can escape not even light!** A diagram of life cycle Description automatically generated - **Universe Trivia** - **The universe is very vast and old and still expanding (red shift -- gives off a red color of the spectrum)** - **The Big Bang Theory is our best current model for origin of the universe.** - **[Big Bang Theory] -- the universe began in a very hot, dense state that expanded & eventually condensed into galaxies** - **The Solar Nebula Theory is our best current idea for the origin of the solar system.** - **[Solar Nebula Theory] -- the planets formed through the condensing of the solar nebula** - **[Order of Events]**: - **Big Bang (oldest)** - **Stars** - **Sun** - **Solar System Formation** - **Life on Earth (most recent)**