MCA 1 REVIEW

ASTRONOMY

  1. These objects are found on the ecliptic
  2. zodiac
  3. planets
  4. sun
  5. Theses are the seasons and dates
  6. spring equinox – March 21- equal day and night – ecliptic crosses celestial equator
  7. summer solstice – June 21 – longest day – ecliptic above equator
  8. vernal equinox – Sept. 21 – equal day and night - ecliptic crosses celestial equator
  9. winter solstice – Dec. 21 – shortest day –ecliptic below equator.
  1. Retrograde – backward motion of a planet in orbit or rotation
  2. Newton – gravity, heliocentric
  3. Galilleo – sunspots, moons of Jupiter, phases of venus, heliocentric
  4. Kepler - heliocentric
  5. elliptical orbits
  6. planets sweep out equal area in equal time
  7. the ratio of the squares of two planet’s periods equal the cubes of their distances from the sun
  8. Copernicus – heliocentric
  9. Aristotle and Ptolemy – geocentric
  10. Distances
  11. to sun – 93 million miles
  12. light year – 6 trillion miles
  13. Phases of the moon
  14. ¾ lit – gibbous
  15. Moon starts to show light – waxing crescent
  16. Phase before new moon – waning crescent
  1. Eclipses
  2. when moon blocks sun – solar eclipse
  3. complete eclipse shadow – umbra
  4. partial eclipse shadow – penumbra
  5. A planets orbit is in the shape of an ellipse
  6. Rotation of earth
  7. noon to noon – solar day
  8. star in sky to the same star – sidereal day
  9. change in earth’s axis – precession
  1. Explain the difference between the heliocentric and geocentric models of the universe. (4 pts – To earn all 4 pts you must mention correctly each term when explaining the difference) Also, what two astronomers believed in the heliocentric model and which astronomer put this information in “print”? (2 pts) Finally, why did early astronomers believe in the geocentric model? (2 pts) Total points: (8)
  1. Find the distance and the diameter of the Astro 108 planet if the baseline = 16,567 km, the parallax = .31 degrees and the angular diameter is .57 degrees. (1 pt for formula, 1 pt for showing work, 2 pts correct answer with units) 4 points per problem – Total points (8)

Distance = Baseline x (57.3/parallax)

Diameter = distance x angular diameter/57.3O

  1. The semi major axis of Mars is 1.524 AU. The eccentricity of Mars is .093. Find the aphelion and perihelion distances. (1 pt for formula, 1 pt showing work, 2 pts correct answer and units – total 4 pts per problem) - Total points (8). Define the following: perihelion, aphelion and eccentricity in complete sentences. (2 pts each – total 6 pts) Total points for question 3 – (14 points)

Perihelion = a(1-e) where a = semi-major axis and e = eccentricity

Aphelion = a(1+e)

  1. Which one of Johannes Kepler’s laws of planetary motion apply to question number 3? (1 point for correct law, 2 pts for correct explanation). Does the perihelion and aphelion distances affect the seasons of Earth? (Must mention both the northern and southern hemispheres). (4 pts) Total points (7)
  1. The diameter of the Sun is 1,392,000 km. Use the scale of 1 meter = 1,392,000 km and calculate the scaled diameter of Earth and Neptune in meters. The actual diameter of Earth is 12, 742 km. The actual diameter of Neptune is 45,432 km. Show all work to earn full credit. (3 pts each) Total points (6)

Sun 1392000km = 12742 km

1m (solve)

  1. Describe to a friend why this picture of the day applies to Astronomy. Mention 3 key observations for 6 points. Mention 2 observations – 4 points. 2 observations 2 points. Remember to add the date of the picture for verification.