 Earth in the Universe Discussion Question Review Question

The Universe Age of the Universe  Believed that the Universe is extremely vast and more than 10 billion years old  Could be up to 13.7 billion years Origin of the Universe  Started with the Big Bang  Most of the earliest atoms were hydrogen and helium  Universe kept expanding in all directions and continues to expand today What is the Universe?  everything that exists in any place  All the space, matter, and energy in existence

The Big Bang Theory  “All matter and energy started out concentrated in a small area and after a gigantic explosion, matter began to organize into subatomic particles and atoms”  Radiation from the Big Bang mixes with energy given off by stars throughout the universe.  Cosmic Background Radiation: Long wave background radiation (microwaves) that appears to come from all directions in the Universe Discuss the Origin of the Universe Video

The Electromagnetic Spectrum What is the Electromagnetic Spectrum? Is there any event in nature that allows you to view the entire spectrum?

The Electromagnetic Energy  Various types of waves that transfer energy throughout space  Measured using the Electromagnetic Spectrum  Scientists infer which elements are in an object based on the electromagnetic energy emitted  Based on composition of signature wavelength produced  Doppler Effect: Shifting of wavelengths  Rela tive movement between Earth and the other celestial objects cause the Doppler Effect Video How are you able to tell if an emergency vehicle is approaching?

The Doppler Effect Red ShiftBlue Shift “Longer” end of the spectrum Indicates that objects are moving apart Most, if not all, stars in the galaxy are shifted to the red end of the spectrum (evidence that universe is expanding) - Rate that universe is expanding is increasing “Shorter” end of the spectrum Indicates that objects are moving closer together Animation 1

What color wavelength would a nearby galaxy emit? What is the approximate value of that wavelength?

The Structures of the Universe A.What is at the center of this photo? B.Explain how this photo was taken. Time Lapse Photo of stars.Galaxy

Galaxies  Collections of billions of stars and gases held together by gravity  Average galaxy has over 100 billion stars  There are over 100 billion galaxies Elliptical GalaxyIrregular GalaxySpiral Galaxy Three common types of Galaxies What is the name of our galaxy and which type of galaxy is it? Video

The Milky Way Galaxy  Galaxy where our Solar System is located  A Spiral Galaxy  least 200 billion stars

Stars  A large ball of gas and dust held together by gravity  Produces a TREMENDOUS of energy  results in shining  Process called Nuclear Fusion  Size of stars vary  Some are larger than our Sun  Some size of planets or moons & no longer emit energy iPad “Planets” Activity What is your Sun Sign?

Nuclear Fusion  When nuclei of smaller elements (H and He) combine to form the nuclei of larger elements  Results in some of its mass converting to energy  Occurs ONLY under extreme heat and pressure  Conditions only found in a star’s core (center)  Energy is radiated into space as electromagnetic energy Explain the role of nuclear fusion prior to the formation of our universe.

How is a star’s brightness determined? LuminosityApparent Brightness - Measurement of how bright a star is compared to the Sun, if all stars were the same distance from an observer. - -How bright a star appears to an observer -Dependent upon the star’s absolute luminosity and its distance away from us ESRT pg 15 Determine the luminosity of the following stars: Betelgeuse, Spica, Barnard’s Star

Star TypeSizeTemperature Notes Additional Notes Main SequenceAverage - As surface temperature increases, luminosity increases - 90% of all studied stars - Most stars spend a majority of their life in this stage - Smallest and coolest stars are called red dwarfs Giant 10 to 100x the diameter of the Sun Low-temperature stars - Red, orange, and yellow giant stars are rare but commonly seen in the night sky because of their large size and high luminosity - Late stage in evolution of main sequence stars Super Giant 100 to 1000x the diameter of the sun Blue super giants: brightest and exhibit the higher temperatures -Late evolution of stars originally more massive than the sun -Explodes in tremendous events known as supernovas White Dwarf Small- Hot on Surface - Not all are white -Low Luminosity -Late stage evolution of Main Sequence Stars Black Dwarf Small- Cool - No more Energy - Former white Dwarf - Very common (as there are trillions of former white dwarfs)

Main SequenceRed GiantWhite Dwarf Supernova explosionBlack Dwarf Video

Evolution of a Star  Stage of a star depends upon its original mass  Process of a star “dying” out may take billions of years  Some stars that were created during Big Bang still exist

The Solar System  Refers to any star or group of 2-3 stars that has other celestial objects orbiting (Satellites)  Satellite: any [celestial] object that orbits or revolves around another object  Our Solar System  The Sun and all celestial object that orbit under its gravitational force  Sun is a medium-size Main Sequence star that is ~ 5 Billion years old  Result of gas and dust condensing into one or more mass concentrations  Due to gravity What celestial object is a satellite of the Earth?

Our Solar System List and describe the 5 parts of our solar system.

Part of Solar SystemSize NotesDescription Planets- Largest objects that orbit the Sun - There are 8 planets - Spherical Shape Moons - Small than the planet it orbits - Celestial object that orbits a planet or asteroid as it orbits a Star - Approximately 175 moons in our Solar System Asteroids - Smaller than Planets - Irregular Shape - rock and/or metallic object -Independently orbits the Sun - No Atmosphere - Asteroid Belt: Large % orbit between Mars and Jupiter Comets Varies- “Dirty Snowball” - Largely ices mixed with rocks and metals - Solid is easily changed into gases when heated - This forms a visible tail Meteoroids Very small rock fragments (size of dime or sand grain) Three categories 1. Meteoroid -orbits the Sun 2. Meteorite –Burns un in Earth’s Atmosphere creating a visible streak 3. Meteor – Reaches and lands on Earth’s surface, forms a impact crater VIdeo Video

Asteroid Our Moon Meteor Comet What is a shooting star?shooting star

Groups of Planets TerrestrialJovian PlanetsMercury, Venus, Earth, MarsJupiter, Saturn, Uranus, Neptune Distance From Sun Closest to the SunFurthest from the Sun SizeSmallMassive CompositionRocky, Solid Many impact craters Gaseous DensityHighLow MoonsFewmany RingsNone ✓✓ ESRT pg 15

Terrestrial Planets Jovian Planets

What motion is illustrated in this image? Describe the motion of each planet as clockwise or counterclockwise.

Rotation of a Planet  Rotation: movement (spinning) of a planet around an imaginary Axis  Axis runs through the center of planet from Pole to Pole  Period of Rotation: amount of time it takes to complete one spin around the axis  6/8 planets rotate counterclockwise (same direction as revolution)  Venus rotates clockwise  Uranus rotates around equator

Balanced Forces  Inertia – concept that an object at rest will tend to remain at rest and an object in motion will remain in motion  Gravitation – the attractive force that exists between any two objects in the universe  Closer together two objects, the greater the gravitational pull  Orbit of a planet around the sun is an example of the balance between inertia and gravitation

 What is the Shape of Earth’s Orbit? An Ellipse

Shape of Planet’s Orbit  Orbit – planet’s path around the Sun  Controlled by Sun’s gravitational pull  Revolution: one complete orbit around the Sun  All planets revolve counterclockwise  All orbital paths are Elliptical or oval shaped  Two center pts of ellipse called Foci  Major axis – line that passes through both Foci across the widest part of the ellipse

An ellipse is like a flattened circle

Foci Major Axis

Eccentricity of an Orbit  Eccentricity – The degree of flattening or “oval-ness” of an ellipse  Slightly eccentric when value is closer to zero (circle = 0)  More eccentric when value is closer to 1 (flat line = 1) ESRT Page 1 Eccentricity = Distance between foci Length of major axis Where would you be able to find the eccentricity of a planet in our solar system? ESRT Page 15

Sun Perihelio n Aphelion Foci Major Axis Animation

Elliptical Orbits  Causes planets to vary in distance throughout its orbit  Closest – Perihelion position  Farthest – Aphelion position Complete the following statement: The area of the triangle on the left is _________ to that on the right. (equal to; less than; greater than) Equal to

PerihelionAphelion Earth’s PositionClosest to the SunFurthest from the Sun Our SeasonEarly WinterEarly Summer DateJanuary 3 rd July 4 th Apparent Diameter of the SunGreatestLeast Orbital speed of PlanetGreatestLeast Kinetic Energy of PlanetGreatestLeast Gravitational Attraction between Planet and the Sun GreatestLeast

Practice  Using the tools provided, demonstrate and calculate the eccentricity of the following ellipses: NumberDistance between Foci (cm) Length of Major Axis (cm) 11 cm 22 cm 34 cm ESRT Page 1