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Planetarium Lab 1 __________________________________
Lost in Space. I’m lost and want to go home, which is north of where I am. How do I use the Big Dipper to
find north? Locate the two _pointer__ stars on the bowl of the Big Dipper, follow these to the tip of the
handle of the Little Dipper, which is __Polaris_
Stars appear to move ___counterclockwise__ around Polaris.
Nature & Culture. Most cultures have recognized Orion's stars as a constellation (by some name). Why is
this? ___it’s easy to recognize and visible at most places people would be
Nature or Culture? Naturally there (N) or culturally constructed (C)?
• Are most constellations primarily a product of nature or culture? N or C?___
• Polaris' special star status (the reason we give it special attention)? N or C?_it stays in the same spot in
the sky no matter who sees it
Winter Hexagon: 1. Rigel is __orion’s foot, 2. Sirius (brightest star) is in CANIS _Major_, 3. Procyon is
in CANIS Minor_, 4. Pollux/Castor are the twin stars of _Gemini_, 5. Capella is in AURIGA which looks
like a _house___ shape, 6. Aldebaran is the red eye of the bull_ (TAURUS).
Give the azimuth and altitude of…
top of planetarium ____---___ ____90_____
Polaris _____0_____ _____35____
Aldebaran ___________ ___________
Rigel ___________ ___________
The Horizon Circle: Oriented by Your Position on Earth (Local)
Circle called: ___horizon________
Vertical measure: _____altitude_______ in ______degrees_________
Horizontal measure: ______azimuth________ in _________degrees______
The Celestial Equator: Defined by Earth's Equator (Global)
Circle called: ___celestial equator
Vertical measure: ______declination___ in ________degrees_______
Horizontal measure: ___right ascension___ in _____hours____________
• What is the relationship between earth's equator & the celestial equator? __the CE is just the extension of
earth’s eq into space
• Does the celestial equator always intersect the horizon at due east and due west? __yes
• Is celestial equator always perpendicular to earth's axis & the north celestial pole? __yes
• What is the altitude of the celestial equator on the meridian as seen from Shawnee? _55
• From a constant terrestrial latitude will the value for the previous answer change? _no
• Is the angle between the celestial equator & horizon the same all year? __yes, always 35 degrees
Is there an absolute (universal) frame of reference within nature by which we and/or extraterrestrials
can know our place in space? __no
What if the United Federation of Planets (Star Trek) legislated such a system? The main basis of this would
be____the galaxy that the federation is in
Cygnus (swan) flies down Milky Way (plane of _The Milky Way (our galaxy) (teapot) which pours out at
galaxy's _center
Is the ecliptic (solar system) in same plane as our galaxy? _no_
Equinoxes and Solstices
Key Dates rising azimuth noon (meridian) altitude setting azimuth
Summer solstice June 21-22
Winter solstice Dec 21-22
Spring/fall equinox March/Sep 21-22
• Sun appears to move east to west along ecliptic. Daily or annually
• Sun appears to move east to west along ecliptic. Daily or annually
• Is the sun's noontime altitude on the meridian always the same through the year? _no__
• Have you ever seen the sun directly overhead (i.e., at the zenith) in Shawnee? _no___
• On what day is the sun highest at noon? ___June 22___ How close to zenith on that day? _12 or so__°
Establish the ecliptic by observation (with planetarium tricks to speed it up)
• Sun appears to slip eastward against the fixed _stars____ about 1° per _day___ along a path called the
_ecliptic_____ which is inclined by __23__° to the celestial equator (see at meridian)
Planetarium Lab 2 _____________________________
How are planets distinguished from the fixed stars?
• Wandering motion (describe): _______as compared with stars______
• Rising points on the horizon: _____different (stars always the same)
• Brightness: Check one--Brighter ___ Less bright ___
• Which constellations, for the most part, contain the planets? __zodiac____
Inner Planets
1. List the 2 inner planets visible to the naked-eye: _Mercury__, __Venus_,
2. How bright can Venus appear? _______bright enough to read by
3. Record the bounded elongation of... Mercury: _______° Venus: _______°
4. Are Mercury and Venus ever visible at midnight? _no_ Why? __they are always near the sun
5. Define conjunction in terms of celestial longitude ___2 objects must have the same celestial longitude to
be in perfect conjunction (like an eclipse)
6. How many conjunctions does Mercury have in a single synodic cycle? _2_ Venus _2_
7. Why is a planet invisible during its conjunction with the sun? __the sun brights it out____________
Outer Planets
1. List the 3 outer planets visible to the naked-eye: __Mars_____, __Jupiter_____, __Saturn_____
2. What is the direction, roughly eastward or westward, for direct and retrograde motions? Answer this
question below by filling in the two blanks:
• Direct motion is ___eastward___________ against the background of fixed stars.
• Retrograde motion is ___westward___________ against the background of fixed stars.
3. Outer planets spend most of their time in which motion, direct or retrograde?
4. Define opposition ____________direct_________________________________
5. Are the outer planets ever visible at midnight? __yes_____
6. When an outer planet is in the middle of retrograde motion, is it closer to conjunction or to opposition?
__opposition (180 degrees from sun)____________
7. When does an outer planet appear at its brightest? _opposition______ (seen only outdoors)
8. In which direction (east or west) does Mars move...
• Prior to its first stationary point? _______
• At opposition? _______
• After its second stationary point? _______
Moon (celestial longitude measurements below are in degrees, and only relative to sun)
Why did pre-modern people called the moon a "planet"? ______________________
1. New moon means the moon is ___0__° of celestial longitude from the sun
2. At the end of first quarter of the moon's drift from the sun it is _90____° of celestial longitude which
direction from the sun? Circle one: east / west
3. How far is the moon from the sun at 2nd quarter's end? 180° Also called full moon
4. How far east of the sun is the moon at 3rd quarter's end? _270__°
5. The moon drifts eastward 13___° along the ecliptic daily; the sun only about _1__°; thus the moon drifts
eastward about _12__° faster than the sun each day; the moon also deviates up to about _5__° above
or below the ecliptic (measured at meridian)
6. Compare the drift eastward relative to the fixed stars of: Sun, Outer Planets, Moon
Which fastest? __moon_____ Which slowest? ___outer planets________ Which medium? __sun___