Unit 1: Basics of Sky | Study Guide

University:
York University
Course:
NATs 1745 | History of Astronomy
Academic year:

2025
Views:

0

Pages:

3
Author:

Anureet Bimb

UNIT 1: Basics of Sky Understand the Sky Moon Phases Planets ____________________________________________________________________________ Basics of Sky DEFINITION: The study of how celestial objects (stars, planets, Moon) appear and move in the sky from Earth. It involves concepts like the celestial sphere, constellations, and Earth's motion affecting our view of the sky. KEY CONCEPTS: The Celestial Sphere: Imaginary sphere surrounding Earth where stars appear fixed. Helps explain how objects move in the sky. Important Parts: Zenith = Point directly overhead . Horizon = Where the sky meets the ground. North & South Celestial Poles = Extensions of Earth’s poles into the sky. Celestial Equator = Extension of Earth's equator. Earths Motions & Their Effects: Rotation (Spinning on Axis) ? Causes Day & Night Earth rotates west to east , so the Sun, Moon, and stars appear to rise in the east and set in the west . Revolution (Orbit Around the Sun) ? Causes Seasons Earth orbits the Sun once per year. The tilt of Earth’s axis (23.5°) causes different seasons. Constellations & the Zodiac: Constellations = group of stars forming patterns Ancient cultures used constellations for navigation & calendars . The Zodiac is a band of constellations along the Sun’s path (ecliptic).

Unit 1: Basics of Sky