Unit 1 - Astronomy Note Outline
I. Modern Astronomy
A. Ancient _____________ believed
1. _________________________ Model
a. Theory that everything orbited the ______________________
B. Modern Science believes
1. ____________________________ Model
a. Theory that everything orbits the ____________________
II. Sun-Earth-Moon System
A. Tools of Astronomy – telescopes
1. ____________________________ telescope
a. uses ______________________ to focus light
2. ____________________________ telescope
a. uses ___________________ to focus light
B. Movements of the Earth
1.__________________ – daily (24 hours); around the axis; day/night
2. _____________________ – yearly (365 days); around the orbit; 1 year
i. Perihelion – closest to the Sun in the orbit
ii. Aphelion – farthest from the Sun in the orbit
3. __________________ – 23.5 degrees relative to the eliptic
i. Along with Earth’s orbit gives us the _______________
4. Solstices
i. ________________ solstice the Sun is directly over the Tropic of ___________________
- occurs around _______________________; ________________ day of the year
ii. _____________________ solstice the Sun is directly over the Tropic of __________________
- occurs around ______________________; _______________ day of the year
5. Equinoxes
i. length of night and day are the same
ii. ____________________ equinox occurs around September _______________
iii. ____________________equinox occurs around March ____________________
6. Precession – a change in direction of the axis, but without any change in the tilt
i. Does not affect the seasons as long as the tilt stays at 23.5 degrees
7. Nutation – the wobbling around the precessional axis
i. A change in the angle (1/2) degree
ii. Occurs over a 18 year period and due to the Moon (exclusively)
iii. Slight decrease/increase of the seasonal effects
8. Barycenter – the point between two objects where they _________________ each other
a. Example – the balance point between the Earth and the Sun
C. The Moon
1. Moon Formation Theories
i. ___________________: during the formation of the solar system a large body got too
close to the forming Earth and got trapped by gravitational pull
ii. ______________________: moon and Earth formed at the same time in the same area
iii. ________________________: a Mars-sized object hit Earth about 4.5 billion yrs ago
during the formation of the solar system
2. Moon Basics
i. one complete cycle in 29 days (1 month)
ii. only see the lit side of the moon because of synchronous rotation
3. Moon Phases – due to the reflection of sunlight
4. Tides – due to the effect of the ___________________ gravity on __________________
i. occur every _______________ hours
ii. ________________ tides = higher than normal because the Moon and Sun are aligned
iii. ________________ tides = lower than normal because the Moon and sun are at right
angles to each other
5. Eclipses
i. _____________________ eclipse = _______________passes between the Earth and Sun
ii. ______________________eclipse = ________________passes through Earth’s shadow
III. The Solar System
A. Kepler’s Laws
1. 1st Law = planets orbit the Sun in an _____________________
2. 2nd Law = an imaginary line between a planet and the Sun must cover the same amount
of ___________ in the same amount of_________________
3. 3rd Law = the size of a planet’s________________ is related to its orbital _________________
B. Planets of Our Solar System
IV. Galaxies and the Universe
A. Earth is in the _______________________ Galaxy
1. It is thought that there is a black hole at the center of our galaxy
B. Formation Theories
1. Big Bang Theory
i. instantaneous expansion of space and matter
ii. Heavy stuff came closer (Terrestrial Planets), lighter (gas) stayed farther out
(Jovian Planets)
iii. Rotation of planets on an axis due to gravitational pull of planets on each other
2. Steady State
i. the universe looks the same on large scales
ii. new matter is created and added to the universe as it expands
3. Measurement
i. Planets distance to the Sun is expressed in Astronomical Units (AU) – the average
distance between Earth and the Sun
C. Earth’s place
1. Universe -> Galaxaies -> Many stars -> Solar System (orbits our Sun) -> Earth
V. Energy From the Sun
A. Combustion vs Burning
1. ________________________ is a type of combustion where flames can be seen
a. Most of the energy from burning is converted into ________________ energy
2. ___________________ is a reaction that takes place without _____________________
a. Most of the energy from combustion is converted into _____________________ energy
B. Nuclear Fission vs Nuclear Fusion
1. In Nuclear Fission – process used in _________________ power plants
a. nuclei ______________
2. Nuclear Fusion – the way in which the _________ produces energy
a. when the nuclei ____________
C. Electromagnetic Radiation: We gain our knowledge by the study of ____________________ emitted
from _________ and other bodies.
1. Gamma Rays, X-Rays, Ultraviolet, Visible Light, Infrared, Microwaves, Radio Waves
2. They are classified by _______________________ and _______________________________.
3. Waves with ______________________________ wavelengths and ______________________ frequencies
have the most energy and therefore do the most damage to DNA.
4. Humans can only see the _______________________ light part of the spectrum with the naked eye.
5. On Earth, only some __________________________, some ___________________________, some ____________
and all _______________________ light wavelengths make it to the surface.
D. Methods of Energy Transfer
1. Conduction – energy is transferred with particles ___________________________ each other
2. Convection – energy is transferred through ___________________________ (liquids and gasses)
3. Radiation – energy is transferred by _____________________________________ _________________________
E. Energy Transfer in Stars
1. Nuclear __________________________________ in the star’s __________________________
2. Energy is passed from one particle to another through _______________________________
3. Energy rises to the surface by _________________________________
4. ___________________________________ of energy out into space by electromagnetic waves
F. Solar Forces in Balance
1. There MUST be equilibrium (balance)!
2. The inward force of ______________________________ of a star must be in balance with the outward
push of _____________________________ from nuclear fusion in the core.