---
title: "SAST2: Earth-Based Astronomical Observations (Georgia Science standard)"
code: SAST2
cite_as: Georgia Standards of Excellence, Science, SAST2
subject: science
grades:
  - high-school
language: en
canonical_url: https://georgiahomeroom.org/standards/code/SAST2
md_url: https://georgiahomeroom.org/standards/code/SAST2.md
alternate_language_url: https://georgiahomeroom.org/es/standards/code/SAST2.md
source_url: https://case.georgiastandards.org/ims/case/v1p1/CFDocuments/27a08dc6-416e-11e7-ba71-02bd89fdd987
source_last_changed: 2025-05-29
data_built: 2026-09-18
publisher: Georgia Homeroom, a free public-interest project of Georgia Civic Data. Not affiliated with or endorsed by the Georgia Department of Education or any school district.
up: https://georgiahomeroom.org/standards/science/high-school.md
index: https://georgiahomeroom.org/standards/index.md
---

# SAST2: Earth-Based Astronomical Observations

Obtain, evaluate, and communicate information to explain astronomical observations made from the point of reference of Earth.

- Subject: Science
- Appears in: High School, https://georgiahomeroom.org/standards/science/high-school.md

## Expectations

- **SAST2.a**: Develop and use models to evaluate the relationship between the relative positions of the Earth, Moon and Sun and observable phenomena. (Clarification statement: This includes moon phases, eclipses, tides, and seasons.)
- **SAST2.b**: Plan and carry out an investigation using the celestial sphere to explain how latitude and time of year affect visibility of constellations and other celestial objects.
- **SAST2.c**: Develop and use models of relative orbital motion of planets within our solar system to explain retrograde motion.
- **SAST2.d**: Use mathematics and computational thinking to explain the relationship between the properties of light and the vast distances in the cosmos. (Clarification statement: This includes but is not limited to the Doppler Effect, cosmological red shifts, parsecs, light years, and astronomical units.)
- **SAST2.e**: Plan and carry out an investigation to analyze the electromagnetic spectrum and spectroscopic data to obtain information about the inherent properties and motions of objects. (Clarification statement: Consider the use of diffraction gratings to analyze spectroscopic wavelength data along with other quantitative telescopic data.)

## Georgia Milestones coverage

No Georgia Milestones blueprint cites this standard.

Source: Georgia Standards of Excellence, published by the Georgia Department of Education at case.georgiastandards.org.