On the Astronomy Final!
- The Night Sky
- Altitude & Azimuth
- Horizon
- Zenith & Nadir
- Celestial Sphere
- What it is
- Diurnal/Annual Motion
- Celestial poles – no diurnal/annual motion
- Celestial Equator
- Right Ascension/Declination
- Ecliptic
- Zodiac what it is, not every constellation
- What is a constellation
- Asterisms – be able to recognize them and their stars
- Conjunctions/oppositions...inferior/superior planets
- Seasons
- Axial tilt 23° 27”...reason for seasons
- Equinoxes and Solstices
- What they are
- Where they are on the Celestial Sphere
- History of Astronomy
- Geocentric vs Heliocentric Models
- Major proponents of each model
- Eudoxus, Aristarchus, Ptolemy, Copernicus, Tycho, Galileo & Kepler
- Problems with each model
- Geocentric ...Retrograde motion of planets
- Heliocentric ... lack of apparent parallax
- Solutions to each problem:
- (Geo) Epicycles.... increasing complexity
- (Helio) That stars are unthinkably far away
- Shape and Size of the Earth
- Since Aristotle all “old world” people knew Earth was a sphere
- 2-reasons:
- Shape of Shadow of Earth on the Moon (in an Eclipse)
- All stars not visible everywhere
- Size of Earth
- Aristarchus proves Sun is larger than Earth and Moon is smaller
- Eratosthenes calculated the size accurately ca 250 BC!
- Galileo’s Discoveries (using a telescope) and what they mean:
- Confirming the Heliocentric Model
- Size of Universe/Stars are Suns
- Planets & Moons are worlds
- Inertia
- Kepler’s 3 Laws
- Know the 3-laws
- Solve a 3rd law problem
- Newton’s laws
- 3 for Motion
- Universal Gravity
- All masses attract each other
- Directly related to mass.
- Obeys the inverse square law
- How these laws affect Astronomy:
- Surface Gravity
- Orbits
- Satellites are falling just missing the planet/star
- Orbital Velocity
- Speed and shape of orbit
- Escape Velocity
- Optics
- What Light is
- Ray, Wave or Particle
- Electro-magnetic waves
- Wave-particle Duality
- Colors are different wavelengths/frequencies of light
- c = fλ (f & λ are inversely related)
- Visible light λ= 400-700nm
- Roy G Biv (increasing f)
- White Light and a spectrum
- The Electro-magnetic spectrum
- Radio, Micro, IR, Visible, UV X-rays and Gamma Rays (Increasing f)
- Know the properties of the different EM-waves
- which pass through the atmosphere
- which are dangerous
- Energy is directly related to frequency
- Relationship between color and temp of stars
- 3 types of Spectra
- Photo-electric effect
- Source of each type
- Continuous ... Hot Solid/ high pressure Gas (star)
- Emission Spectrum...bright lines...Hot Gas
- Absorption Spectrum...dark lines...passed thru cold gas
- E/A spectra act like elemental fingerprints
- Doppler effect...Red & Blue Shifts.
- 5 ways light changes direction.
Reflection, Refraction, diffraction, scattering, gravity
- what each is
- basic rules
- Optical instruments
- No optical effects, aberrations or image questions!
But know why reflectors make better big telescopes
- Telescopes
- Properties of the parts of a telescope
- Properties of the scopes
- Properties of the image
- How the three above are related
- Types of telescopes
- What we’ve learned about the Earth
- Numerical Stats: Radius, Mass Density, Orbital Radius
- Layers of the Lithosphere
- Composition of the Lithosphere
- Temperature Scales and Units
- Know the 3 used Fahrenheit, Celsius and Kelvin
- Zero on Each scale and Absolute Zero
- Know what a Light-year, and an Astronomical Unit are