More Astronomy Exam 1 Flashcards

Lunar Eclipse - Moon Phase

Full Moon

Lunar Eclipse - Diagram

Earth is between the Sun and Moon, casting a shadow on the Moon.

Lunar Eclipse - Visibility

Visible to all observers on the night side of Earth, assuming clear weather.

Lunar Eclipse - Appearance

Moon appears reddish due to Earth's atmosphere filtering sunlight.

Lunar Eclipse - Frequency

Doesn't happen monthly due to Moon's tilted orbit.

Solar Eclipse - Moon Phase

New Moon

Solar Eclipse - Diagram

Moon is between Earth and Sun, casting a shadow on Earth.

Solar Eclipse - Visibility

Visible only in narrow path of totality.

Solar Eclipse - Corona

Sun's outer atmosphere, visible during total eclipse.

Annular Eclipse - Appearance

Ring of fire; Moon covers center of Sun but not edges.

Annular Eclipse - Moon Phase

New Moon

Annular Eclipse - Conditions

Moon is farther from Earth (apogee), appears smaller.

Annular Eclipse - Safe Viewing

Use eclipse glasses or pinhole projector.

Round Earth Evidence

Ships disappear bottom first; curved shadow during lunar eclipse; different constellations at different latitudes.

Spinning Earth Evidence

Foucault pendulum, Coriolis effect, star trails.

Ptolemy's Model

Earth-centered; planets move in epicycles.

Copernicus' Model

Sun-centered; circular orbits.

Tycho Brahe's Model

Hybrid; Sun orbits Earth, planets orbit Sun.

Retrograde Motion - Ptolemy

Explained using epicycles.

Retrograde Motion - Tycho

Can mimic retrograde motion.

Model Accuracy

Kepler's elliptical orbits improved predictions.

Venus Phase - Position a

Near Earth, crescent phase.

Venus Phase - Position e

Far from Earth, full phase.

Venus Size Variation

Appears larger when closer (crescent), smaller when farther (full).

Full Venus - Ptolemy

Not possible; Venus always between Earth and Sun.

Full Venus - Tycho

Possible; Venus orbits the Sun.

Parallax Definition

Apparent shift in position of nearby stars due to Earth's movement.

Parallax Effect

Smaller for more distant stars.

Parallax Prediction

Predicted by heliocentric models.

Parallax Observation

First observed in 1838 by Bessel; ruled out geocentric models.

Observations Ruling Out Ptolemy

Phases of Venus, stellar parallax.

Observations Ruling Out Tycho

Stellar parallax doesn't fit well.

Model Correction

Elliptical orbits needed to match observations.

Major Planet Criteria

Orbits Sun, spherical shape, cleared orbital zone.

Dwarf Planet Criteria

Orbits Sun, spherical, hasn't cleared orbital zone.

KBOs and TNOs

KBOs: icy bodies beyond Neptune; TNOs: includes KBOs and farther objects.

Asteroid Belt

Between Mars & Jupiter; rocky bodies.

Kuiper Belt

Beyond Neptune; icy bodies.

Oort Cloud

Far outer edge; source of long-period comets.

Dwarf Planet Locations

Ceres: Asteroid Belt; Pluto: Kuiper Belt; Eris: Scattered disk.