Discovering the Night Sky Flashcards
What are the 3 forms of Earth’s motion?
Rotation: Earth spins on its axis, taking one day.
Revolution: Earth orbits the sun, taking one year.
Precession: Slow circular motion of Earth’s axis over 26,000 years.
What is the relationship between zodiacal constellations?
The Sun visits all 12 Zodiacal Constellations once a year, forming the basis for Astrology.
What causes apparent motion of celestial bodies?
The westward motion of the Sun, Moon, and stars is due to Earth’s rotation, observed differently based on one’s location.
What are the three geographical coordinates, and what is there impact on time?
Latitude: North-South, parallels
Longitude: East-West, meridians, Prime Meridian in Greenwich
Altitude: Elevation above the horizon
Time Zones: 24 segments based on Earth’s rotation and the International Dateline
What are the causes of seasons?
The tilt of Earth’s axis and its orbit around the Sun cause seasons, with varying sunlight concentration and daylight duration.
What influence does the moon have on the earth? What causes the moon to “change”?
Influences tides
Lunar Phases: Synodic period (29.5 days), Sidereal month (27.3 days)
Eclipses: Penumbral, Partial, Total
What kinds of solar eclipses are there?
Total: Entire Sun covered by Moon
Partial: Part of Sun covered
Annular: Ring of Sun visible around Moon
What is the divison of the solary system?
Inner Solar System: Mercury, Venus, Earth, Mars
Outer Solar System: Jupiter, Saturn, Uranus, Neptune
How are stars grouped? Compare ancient versus modern systems.
Ancient Constellations: Grouped stars into legends
Modern Constellations: 88 official regions for locating celestial objects
Give examples of different calendars.
Lunar Calendars: Based on moon phases, e.g., Islamic calendar.
Lunisolar Calendars: Synchronize lunar cycles with the solar year.
Gregorian Calendar: Introduced by Pope Gregory XIII, with leap years for accuracy.
What is the celestial sphere?
Imaginary sphere surrounding Earth, with coordinates for locating celestial objects:
Right Ascension: Like longitude
Declination: Like latitude
