Download sun, moon, earth notes

What is Astronomy?
• The study of the objects in Space
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Oldest science
Earth, Moon, Sun Positions
Planets and the Solar System
Stars and Galaxies
• Levels:
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Biosphere / Planet
Solar System
Galaxy
Universe
MOTION of the EARTH
• Rotation – Spinning on axis
• 1 Rotation = 1 Day
• Revolution – traveling in orbit around the sun
• 1 Revolution = 365.24 Days
• Leap Year – an extra day added in February once
every 4 years to make up for the extra ¼ day it
takes for each revolution
MOTION of the EARTH
• Tilt of Axis  23.5o
• Summer and Winter– Earth is tilted towards or
away from the sun
• Solstice – the day when the axis is pointed directly
at or away from the sun
• Northern Hemisphere season is opposite of
Southern Hemisphere
• Summer in the northern hemisphere (axis
pointed toward the sun) is winter in the southern
hemisphere (axis pointed away from the sun)
• Amount of Daylight Changes
• Tilt of the Earth’s axis also explains why the
amount of daylight changes from summer to
winter
• Spring and fall– The earth’s axis is not tilted
toward or away from the sun
• Equinox – the day when the amount of
daylight and night time is equal everywhere on
Earth
• Vernal Equinox – first day of spring
• Autumnal Equinox – first day of fall
MOTION OF THE MOON
• Moon revolves around Earth
• 27 days = 1 revolution
• Rotates at same rate
• Same side of moon faces Earth
• Phases - How much of lighted side you see from
Earth
• Waxing – getting bigger
• Waning – getting smaller
• Crescent – see a little bit
• Gibbous – see most of it
Phases repeat every 29 days (approx. 1 month)
MOTION OF THE MOON
• Eclipse – when an object in space casts it’s
shadow on another object
• Lunar Eclipse – Earth casts shadow on the moon
• Solar Eclipse – Moon casts shadow on the Earth
• Umbra – darkest part of the shadow
• Full Eclipse
• Penumbra – less dark part of the shadow
• Partial Eclipse
MOTION OF THE MOON
• Tides – the rise and fall of water every 12.5 hours
• 4 tides every day  high, low, high, low
• Caused by the gravitational pull of the moon and sun on
the water on Earth
• Moon has biggest effect
• Oceans are effected the most
• Spring Tide – moon, sun and Earth are in straight line
• Greatest difference in height of water between high
tide and low tide
• Neap Tide – moon, sun and Earth form a right angle
• Smallest difference in water height between high tide
and low tide