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Natural Science - Year I

Unit 5: Planetary Motions

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Lab Assignment for Unit 5

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Natural Science Unit 5 Laboratory Activity:
Planetary Movements

Goal: Observing planets against the background sky

Materials and Equipment:


Attached is a map of the Seattle, WA sky, for 14 October 2022 at 07:00 pm, local Daylight Savings Time. The middle slightly-curved green line is your horizon; notice the compass points along it. You are looking south in this partial view. The area below this line shows the stars that are below the horizon. The curved orange line is the path of the sun (called the ecliptic) against the background of the sky. The blue line is the celestial equator. Points along this line are marked at the boundaries of the diagram in hours of right ascension. The sun is near 12 hours of right ascension at the autumnal equinox, half-way around the sky from its 0 hour position at the vernal equinox.

Using the map as a starting point, choose a clear night at a reasonably light-free location, begin observing as soon as it is dark enough, and try to locate the following objects:

  1. the moon, if it is visible (it will be at first quarter on October 16; notice it's position on the map above the south horizon)
  2. the constellations Pisces and Sagittarius (these lie along the ecliptic)
  3. the constellation which is setting in the west
  4. the constellation which rising in the southeast
  5. the planets Mars and Mercury will set before the sun sets; if you want to see them, you will need to get up before dawn.
  6. the planet Venus will set after sunset; you might see it earlier in the evening -- at 9pm it is already set.
  7. the planets Saturn and Jupiter, pretty much due south.
  8. if you know other constellations, you may want to try and find them as well.
  9. note any differences in locations between your observations and the ones on the map (is Aquila directly over head? what time is it?)
Be careful when trying to find things using the map. This is a 180° map, from east to west looking south, but, like the Mercator projection maps of Earth, things at the top and bottom are s-t-r-e-t-c-h-e-d sideways. Also, only half the sky is visible at any one moment. Where are your "boundaries"?

Data Analysis:

There is no formal data analysis for this observation.


Your written report should include the following sections: