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The Arizona STEM Acceleration Project

The Celestial Coordinate System

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The Celestial Coordinate System

A [11-12] grade STEM lesson

M. Winters

July 2023

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Notes for teachers

Celestial coordinates is a complex and fairly advanced topic & many students find it difficult. This lesson includes some extensive guided notes for students and then a hands on activity for them to practice with the coordinate system. The activity includes two components; the first is done using paper maps and rulers to estimate coordinates, the second involves using a sky simulation application to verify the accuracy of the work the students did with the paper maps.

List of Materials

  • Projector for displaying the guided notes to the students.
  • Paper copy of the celestial coordinates activity (1 per student)
  • Clear plastic ruler (1 per student)
  • Computer with “Stellarium” application installed (1 per student or 1 per pair of students)

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Standards

Plus HS+E.E2U1.16

Obtain, evaluate, and communicate information

about patterns of size and scale of our solar system, our galaxy, and the universe.

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Core Ideas

Earth & Space Science: Earth Systems

Earth & Space Science: Earth & The Universe

Technology: Knowledge Constructor

Mathematics: Counting & Cardinality

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Objective(s):

At the end of the lesson the student will be able to:

Make comparisons between Terrestrial & celestial coordinate systems.

Define Right Ascension & Declination.

Identify Right Ascension & Declination axes on maps of the sky.

Utilize Right Ascension & Declination coordinates to locate objects and location on maps of the sky.

Measure Right Ascension & Declination coordinates accurately to the arc minute.

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Agenda (lesson time)

This lesson will take 2-3 class periods at one hour each. The guided notes will likely take an entire period or most of a period. The hands on activity will take students at least one full period and certain students will definitely take longer.

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Intro/Driving Question/Opening

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How do we locate object or locations here on the Earth?

How do we locate objects or locations in the sky?

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CELESTIAL COORDINATES

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CELESTIAL COORDINATES

  • The Earth has been mapped in such a way that you can use a system of coordinates to locate any specific object or location.
  • What measurements are used to locate specific spots on the surface of the Earth?
  • Latitude & Longitude

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EARTH COORDINATES

  • Latitude is the angular distance north or south of the Earth’s equator.

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  • Measured in degrees, arc minutes, & arc seconds.

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  • Example: N 32° 23’ 40”

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NORTH

EQUATOR

SOUTH

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EARTH COORDINATES

  • Longitude is the angular distance east or west of the Earth’s prime meridian.

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  • The Prime Meridian is a line from the north pole to the south pole that passes through Greenwich England.

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EARTH COORDINATES

  • Measured in degrees, arc minutes, & arc seconds.

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  • Example: W 110° 57’ 50”

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THE EARTH’S PRIME MERIDIAN

The zero point for measuring Longitude

Splits the Earth into Eastern & Western Hemispheres

West

East

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A handheld GPS unit showing Earth coordinates in

“degrees, minutes, seconds” format.

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CELESTIAL COORDINATES

  • Well……………….. In the sky we don’t use latitude and longitude, that would be FAR TOO EASY!

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  • In the sky (celestial sphere) we locate objects using declination & right ascension.

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CELESTIAL COORDINATES

  • Declination: Angular distance above or below the celestial equator.

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  • Equivalent of latitude.
  • Measured in degrees (+ or –), arc minutes, & arc seconds.
  • Example: +34° 35’ 57”

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CELLESTIAL COORDINATES

  • Right Ascension: Angular distance away from a meridian line running through the vernal equinox. (NOT the Prime Meridian!!!)
  • Equivalent of longitude
  • Measured in hours, arc minutes, & arc seconds.
  • Example: 18h 15’ 35”

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15 h

Determine the right ascension coordinate of the star.

16 h

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12 h

Determine the right ascension coordinate of the star.

10 h

11 h

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23 h

Determine the right ascension coordinate of the star.

22 h

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+24°

Determine the declination coordinate of the star.

+23°

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-52°

Determine the declination coordinate of the star.

-55°

-56°

-54°

-53°

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THE CELESTIAL SPHERE

  • (((Lab: Celestial Coordinates)))

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  • THE END…

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Hands-on Activity Instructions

  • Students may work in pairs but each student should fill out and complete their own activity sheets.
  • Students should be able to work with very little help from the teacher once they get started.
  • Students should receive the activity sheets first and complete “Part-1” before they are allowed to have a computer.
  • The teacher should be prepared to provide a LOT of supplemental help to students as they get started as MANY students struggle to understand coordinate systems of any kind.

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Hands-on Activity Instructions

  • Activity continued.

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Hands-on Activity Instructions

  • Map #1 for the activity

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Hands-on Activity Instructions

  • Map #2 for the activity

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Hands-on Activity Instructions

  • Activity continued

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Assessment

The assessment is the hands on activity from the past 5 slides.

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Differentiation

This lesson may be changed, updated, modified, extended, or shortened in a variety of ways; feel free to do so…

Remediation

Extension/Enrichment

The students will definitely need further practice with using celestial coordinates. The maps that are included with the activity could be used for further practice with the students identifying coordinates of additional objects. There are also MANY star maps available online, which could be downloaded and used for practice and or quizzes with the celestial coordinate system.