The study of the universe. Astronomy The study of the universe.

The Big Bang Theory Scientists explanation of the origin of the universe Explosion caused matter to expand from the center out Evidence - Microwave radiation, galaxy & star movement

The Universe Contains about 100 billion galaxies Galaxy – a huge group of stars, gas, and dust held together by gravity Gravity – the attraction of two objects according to their relative masses.

The Known Universe (2016) This picture of the known universe was created by Pablo Carlos Budassi combining maps from Princeton and images from NASA.

The Milky Way Galaxy Consists of several hundred million stars

Extended arms with a bulge in the middle Types of Galaxies-pg.138 Type Sketch Shape Stars/Size Spiral (Milky Way)   Extended arms with a bulge in the middle Large Old stars in the middle New stars in the arms Elliptical Sphere or egg shaped Old stars only Irregular No definite shape Small Fewer stars

Star Characteristics Brightness – determined by distance away from Earth and size Size – named “dwarf” ,”giant” or “supergiant”

Temperature Range (C) Color & Temperature Color shows temperature (like camp fires) Draw the table below. Fill in with pg. 125 Feel Color Temperature Range (C)  Hottest    Hot  Medium  Cool  Coolest

Magnitude- measuring star brightness based on distance Apparent magnitude – brightness of a star as it appears from Earth

Example – Star A = 0.15 brighter Absolute magnitude – brightness of a star compared to other stars if they were next to each other Brighter = smaller # Example – Star A = 0.15 brighter Star B = 1.5

Life of a Star Animation Use pg. 127 Fill in the diagram with labels and sketches in your science notebook Write a 3-5 sentence summary about the steps in the life of a star Low Mass High Mass Highest Mass  

Closing Question: What factor determines the end result of a star’s life? Raise your hand to answer: Right hand = gravity Left hand = mass

The Sun (Our star) Medium mass star Fueled by nuclear fusion When hydrogen atoms combine to make helium until the hydrogen runs out

Earth, Moon, and Sun Revolution – spinning around another object Earth revolves around the sun in 365.4 days Rotation – spinning on an axis (causes day & night) Earth rotates on its axis once in 24hours

Seasons = different depending on location Northern Hemisphere Summer (June-August) Southern Hemisphere Winter (June-August)

Seasons – caused by tilt of Earth on its axis Solstice = most direct or indirect sunlight Winter Solstice = December 21/22 Shortest day (8-10 hours) Summer Solstice = June 21/22 Longest day (15-18 hours) Equinox = equal sunlight Vernal (Spring) Equinox – March 20/21 Autumnal Equinox – September 22/23 About 12 hours day and 12 hours night

Solstices & Equinoxes

Myths & Hypotheses about where the moon originated Luna: Earth’s Moon Myths & Hypotheses about where the moon originated

How was the moon created? Let’s discuss…

The Accepted Theory… A large body collided with Earth early in its formation A part of Earth broke off It was caught by Earth’s gravitational force forming the moon

Moon facts… The moon does not produce light, it reflects the light from the sun Phases are the shapes seen from Earth (shadows) The moon completes a full set of phases each time it revolves around the Earth (every 28 days)

Phases of the Moon Waxing – Left Shadow (bigger) New Moon Waxing Crescent First Quarter Waxing Gibbous Full Moon Waning Gibbous Last Quarter Waning Crescent Waxing – Left Shadow (bigger) Waning – Right Shadow (smaller)

Difference from Earth to Space In Space = half is lit and half shadow From Earth= You see lit and part of the shadow

Phases of the Moon – Space/Earth Views

Which moon phases are pictured? New Moon Waxing Gibbous

Eclipses Penumbra = light shadow on outside of an eclipse Caused by shadows Two types: Solar and Lunar Definitions: Penumbra = light shadow on outside of an eclipse Umbra= dark center shadow of an eclipse

Lunar Eclipse Sun, Earth, Moon (Full Moon) Line up in above order Earth’s shadow blocks moonlight Occurs often (Next one – April 4 @ 12:01am)

Solar Eclipse August 21, 2017 Total: in 2205 Sun, Moon, Earth (New Moon) Line up in above order Moon’s shadow blocks some sunlight Occurs rarely; seen in few places Harmful to look at Next in AZ Partial: August 21, 2017 Total: in 2205

Tides Caused by the moon and sun’s gravity pulling on Earth's oceans.

Tide Cycle Tides change every 6 - 8 hours There are high tides and low tides

Spring Tides – Big change between high and low tides Occur when the moon and sun line up with Earth During a new moon or full moon

Neap Tides – Not much change Occur when the moon is at a right angle to the Earth and sun During a 1st Quarter or 3rd Quarter moon

Basically… the Sun and Moon Don’t want to share!!! Spring and Neap Tides