Name:
PD.
Unit 2 – The Exosphere (#
2.3 The Solar System
1.
2.
3.
Formation of the Solar System
a. Out in the vacuum of space, a cloud of dust and gas is known as a _____________________
i. Consists of 92% _____________, 7% ________________, and less than 1% heavy
elements
b. They rotate slowly and contract due to __________________.
c. As clouds contract, the ___________ faster.
i. Think of Ice skaters
d. Nebular Theory
i. Scientific studies of nebulae led to theory on the origin of the solar system
1. Known as the ________________ Theory.
ii. According to this theory, the sun and ________________ formed from a rotating
________ of dust and gas.
iii. As rotation speed increased, the _____________ flattened out and matter became
more concentrated in the center, where the _________ eventually formed
e. Planetesimals
i. Growth of planets started as solid bits of matter that _______________ into each other
and clumped up, a process known as ___________________.
The Planets
a. Two classes of planets
i. __________________
ii. __________________
b. ________________ planets (Mercury, _____________, Earth, Mars)
i. _____________ composition, smaller, lie close together
ii. Made mostly of ____________ elements (such as Iron and Nickel)
c. ________________ planets (Jupiter, Saturn, _______________, Neptune)
i. _____________ composition, very large, widely spread apart
ii. Made mostly of _____________ elements (such as Hydrogen and Helium)
Terrestrial Planets
a. Mercury: The Innermost Planet
i. Smallest planet
ii. Like Earth’s Moon, absorbs most sunlight due to lack of ___________________.
iii. Surface Features:
1. Cratered highlands, smooth terrains (a lot like our moon)
2. Very dense planet (indicates ____________ core)
iv. Surface Temperature
1. Has greatest temp. __________________ of any planet
v. Other info: one full day-night cycle takes ______ Earth days, revolves quickly
b. Venus: The Veiled Planet
i. Orbits sun in nearly perfect ______________
ii. Similar to Earth in size, density, __________, and location in solar system
1. Earth’s ____________
iii. Surface Features:
1. Covered in thick ___________ visible light cannot penetrate
2. Magellan spacecraft revealed topography similar to Earth and _____________.
3. _______________ and tectonic activity shape Venus’s surface
4. Most of surface consists of plains covered by ___________________, 8% is
highlands
Name:
PD.
Unit 2 – The Exosphere (#
iv. Surface Temperature:
1. Atmosphere is 97% _____________________________
2. Surface temperatures reach 475o C or 887oF! (Wow that’s hot)
3. Only small amounts of ___________ vapor and nitrogen detected
4. Venus’s atmosphere contains 25km thick ___________ layer and has pressure
______ times Earth at the surface.
The Greenhouse Effect:
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
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Greenhouse gasses keep the surface of a planet warm/hot through the Greenhouse Effect
o Gases include carbon dioxide, ____________, water vaper, and _________________
Sun strikes the ground and warms it up, the ground tries to “give back “ some heat into
space but these gases ___________ the heat.
Venus is the _____________ planet in the solar system due to this
c.
Mars – The Red Planet
i. Greater interest to study than any other planet
1. Easy to ____________
ii. Known as the “Red Planet” since it appears as a reddish ball from Earth
iii. Most prominent features are its brilliant white _____________________
1. Made of water ice covered by a layer of ________________________.
iv. The Martian Atmosphere
1. Martian atmosphere ______ the density of Earth’s
2. Mostly ______________________ with a little bit of water vapor
3. Extensive __________ storms ravage the surface, with winds up to __________
that can go on for weeks.
v. Surface Features of Mars:
1. Looks like a ____________ desert, with sand dunes and ______________
craters covered with dust
2. Northern Hemisphere covered by many large _________________, Southern
Hemisphere is highly __________________
a. Olympus Mons is the size of Ohio and 23km high (2.5 times Mt.
Everest)
3. Has many canyons much larger than our Grand Canyon
a. Valles Marineris is the largest at ________ km long and ____ km deep
vi. Water on Mars
1. Some area show ______________ patterns that look like streams
2. If there was water, where did it go?
a. Most scientists believe that most of these patterns were due to
collapse of _____________________ by slow melting of
______________________.
Challenge question: Why are surface temperatures so high on Venus?
Answer:
Name:
4.
5.
PD.
Unit 2 – The Exosphere (#
Jovian Planets
a. Jupiter – The Giant Among Planets
i. has a mass _____ time greater than the mass of all other planets combined
ii. Rotates faster than any other planet  ______ hours
iii. Most striking features are the colored ___________ and the ______________________
1. Great Red Spot is a _______________ storm twice the size of Earth
iv. “___________ that Failed”
1. Not enough _________ to allow nuclear fusion to begin in its __________.
v. Structure of Jupiter
1. Jupiter is 90% ________________ and _______________, with the rest being
methane, ammonia, water and sulfur.
2. At 1000km below the clouds, pressure is great enough to compress
_____________________ into a liquid
a. Jupiter thought to be gigantic _____________ of liquid hydrogen
3. Jupiter is believed to have a rocky and ________________ central core (liquid
or solid
b. Saturn – The Elegant Planet
i. Saturn is almost __________ as far from the Sun as Jupiter
ii. Composition/structure similar to ______________.
iii. Most prominent feature of Saturn is its system of ______________
1. All gas planets have ring systems, but Saturn’s is the most ________________.
2. Made of individual particles of ________ and ___________.
3. Likely originated from broken up ____________ and other travelling bodies.
c. Uranus – The Sideways Planet
i. Unique feature of Uranus is that it rotates “_____________________”.
1. Looks like it is _____________
2. Discovered by the Voyager 2 spacecraft in 1986.
ii. Made mostly of ______________ (83%), 15% ________________, and 2% ___________
1. Blue-green color of planet due to _______________ in its atmosphere.
d. Neptune – The Windy Planet
i. Has a dynamic atmosphere, much like those of Jupiter and _______________.
ii. Winds over ___________ km/hr encircle Neptune
1. One of the ______________ places in the solar system
iii. Has an Earth sized spot called the __________________________, assumed to be a
large rotating storm
iv. Has white, cirrus-like clouds made of frozen _____________.
Objects beyond Neptune
a. __________ was discovered in 1930 and up until 2006, it was considered the _______ planet of
our solar system.
b. It is now characterized as a ____________ planet, which is defined by the following criteria:
i. An object orbiting the ________
ii. Is _________ because of its own gravity
iii. Not cleared the _____________ around its orbit
iv. Is not a ______________ of another planet
c. In recent years, astronomers have discovered hundreds of objects beyond Neptune’s orbit and
have term them _______-________________ objects (TNOs)
d. Most are just small chunks of _________
e. TNOs exist in a region known as the _____________ Belt.
Challenge question: What may have caused Uranus’s unique axis of rotation?
Answer:
Name:
6.
PD.
Unit 2 – The Exosphere (#
Satellites of Other Planets
a. Until the 1600s, astronomers believed Earth was the only planet with a ___________.
b. In 1610  Galileo discovered four major moons of the planet, _______________.
c. Since then, astronomers have discovered all planets within our solar system, with the exception
of _______________ and _______________, have moons
7. Jupiter’s Moons
a. Jupiter’s satellite system consists of _______ moon, the four largest were discovered by Galileo
(Galilean moons)
i. Io, ______________, _________________, and Callisto
b. All travel in nearly _____________ orbits around the planet
c. JUPITER HAS THE MOST MOONS IN OUR SOLAR SYSTEM
d. Io
i. the ___________ of the Galilean moons
ii. One of three known ___________________ active bodies in the solar system
1. The others are _____________, and Neptune’s moon _______________.
e. Europa
i. The _______________ of the Galilean moons
ii. Has an _______ surface that is crossed by many _____________ features.
f. Ganymede
i. The ______________ moon in the solar system
ii. Contains:
1. ______________ areas
2. ______________ regions
3. Areas covered by numerous parallel ______________
g. Callisto
i. The ________________ of the Galilean moons
ii. Densely cratered, much like ____________ moon
8. Moons of Mars
a. Mars has ______ moons, Phobos and ____________
b. Both through to be _________________ asteroids
c. Surfaces are dark, like the _____________ of Earth’s moon
d. Exhibit _________________, showing old age
9. Moons of Saturn
a. Saturn’s satellite system consists of _______ moons
b. __________ is the largest and is bigger than ___________________
i. It is the _____________ largest moon in the solar system
ii. One of the only moons in the solar system known to have a substantial
____________________10. Moons of Uranus
a. Uranus has _____ moons
b. _______________ is the most interesting
i. It is the innermost of the five largest moon
ii. Has a greater variety of __________________ than any body yet examined in the solar
system
iii. Was once thought to be broken apart and ____________ back together, but now
thought to have ______________ activity
11. Moons of Neptune
a. Neptune has _____ known moons
b. _____________, Neptune’s largest moon is nearly the size of Earth’s moon
i. Only large moon in the solar system that exhibits ________________ motion (clockwise)
ii. This motion indicates that Triton formed ________________ of Neptune and was
_____________________ captured.
Name:
PD.
Unit 2 – The Exosphere (#
12. Pluto’s Moons
a. Pluto is unusual in that it has a moon, _____________.
i. Charon is more than ________ the size of Pluto itself
b. Pluto has ______ other moons
i. Nix and Hydra were both discovered by the Hubble Telescope in 2005.
ii. Kerberos was discovered in 2011 and Styx in 2012
13. Asteroids
a. Asteroids are small rocky bodies that orbit the ________.
i. Most are <1 kilometer in size
b. The largest, the dwarf planet Ceres
c. Most asteroids lie in asteroid ________ between the orbits of _________ and _______________
d. Composition can vary from Carbon, Iron, Nickel, and Silicon materials
14. Meteoroids, Meteors, and Meteorites
a. Smaller particles, possibly coming from asteroids or comets, orbiting the Sun are known as
________________
i. Vary in size from small grains up to 1 meter
b. When a meteoroid enters Earth’s atmosphere, ______________ heats the surface and causes it
to ________ up.
i. As it burns, it produces a bright streak of light known as a __________________, which
is commonly referred to as a “______________ star”
c. Any part of a meteoroid making contact with Earth’s surface is known as a __________________
15. Comets
a. Among the most interesting and unpredictable bodies in the solar system
b. Comets are small bodies of ______, _____________, and ______________ dust
c. Travel in very _______________ orbits that carry them far beyond Pluto
i. Takes hundreds of thousands of years
d. Most famous is ______________ Comet, which passes by Earth every 76 years (next is 2061)
e. Comet Structure
i. ________(nucleus): made of rock, metals, and ice
ii. ________: cloud of gas and dust surrounding the core
iii. ________: electrically charged particles (_________) resulting from sunlight changing
comet’s ice into _______
16. The Oort Cloud
a. Extended _________ of icy objects that exist in the outermost reaches of the solar system
b. Roughly _______________ and is the origin of most of the ___________________ comets
c. Theorized to be the leftover pieces of material that formed the ______ and _________________
Challenge question: Compare and contrast a meteoroid, meteor, and meteorite.
Answer: