solar system & planets

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Solar system & planets

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Page 1: Solar system & planets

WELCOME

Page 2: Solar system & planets

The Universe, Solar System, and Planets I

Questions:How do we know the Big Bang happened?

How do we know the Universe is expanding?

What is the timeframe of Universe evolution?

Page 3: Solar system & planets

News Flash: NASA/CNN report first starsformed early than once thought

Page 4: Solar system & planets

Edwin Hubble at Mt. Wilson

Hubble guiding the Hooker100 inch telescope in 1923. The Hooker 100 inch telescope atop Mt. Wilson

near Pasadena, CA. It was the largest telescope in the world from 1917-1947.

Hubble’s observations at the 100 inch during the1920’s led him to the conclusion that the universe is expanding, and that an object’s recession velocityis proportional to its distance from the observer.

Page 5: Solar system & planets

A deep image of an “empty”portion of the sky with theHubble Space Telescopereveals that the universe isfilled with galaxies- many justlike our own. The lightwe see from the most distantgalaxies has traveled approx-imately 10 billion years to reach us.

Deep Hubble Space Telescope Image

Page 6: Solar system & planets

Using the Doppler Effect to Measure Velocity

Blueshift Redshift

Page 7: Solar system & planets

Calcium

Magnesium

Sodium

Galaxy Spectrum

Stellar Spectrum

Spectra of a nearby star and a distant galaxy

Star is nearby, approximately at rest Galaxy is distant, traveling away from

us at 12,000 km/s

Galaxy Spectroscopy

Page 8: Solar system & planets

Origin of the Universe -Did It Begin with a Big Bang?

Page 9: Solar system & planets

Penzias and Wilson, 1965 Arecibo Dish, Puerto Rico

Discovery of the Background Radiation from initial Big Bang-Long wavelength-came from all directions

Page 10: Solar system & planets

Early History of the Universe

• Matter as we know it did not exist at the time of the Big Bang, only pure energy. Within one second, the 4 fundamental forces were separated

– gravity - the attraction of one body toward another

– electromagnetic force - binds atoms into molecules, can be transmitted by photons

– strong nuclear force - binds protons and neutrons together in the nucleus

– weak nuclear force - breaks down an atom’s nucleus, producing radioactive decay

Page 11: Solar system & planets

Early History of the Universe

• After 3 minutes, photons and neutrons began to fuse to form the nuclei of hydrogen and helium atoms

• About 300,000 years later, temperatures were cool enough for complete hydrogen and helium atoms to form

• Photons escaped from matter about the same time, and light existed for the first time

Page 12: Solar system & planets

Changing Composition of the Universe

• 200 million years later, with expansion still occurring, stars and galaxies began forming from leftover matter - hydrogen and helium

– nuclear fusion in stars has reduced the original composition of 100% H and He to 98%

– when a dying star explodes, the heavier elements created by fusion are blown into space to be recycled by newly forming stars

– the overall composition of the galaxies is gradually changing to the heavier elements

Page 13: Solar system & planets

The Solar System - Its Origin The Solar System - Its Origin and Early Developmentand Early Development

� Our solar system, Our solar system, part of the Milky part of the Milky Way galaxy, Way galaxy, consists of the Sun, consists of the Sun, nine planets, 64 nine planets, 64 known moons, known moons, many asteroids, many asteroids, millions of comets millions of comets and meteorites, as and meteorites, as well as well as interplanetary dust interplanetary dust and gasesand gases

Page 14: Solar system & planets

The Solar System - Its Origin The Solar System - Its Origin and Early Developmentand Early Development

Page 15: Solar system & planets

General Characteristics of the Solar System

• Planetary orbits and rotation– planet and satellite orbits are in a common plane– nearly all planet and satellite orbital and spin motions are

in the same direction– rotation axes of nearly all planets and satellites are

roughly perpendicular to the plane of the ecliptic

Page 16: Solar system & planets

General Characteristics of the Solar System

• Chemical and physical properties of the planets

– the terrestrial planets are small, have a high density, and are composed of rock and metallic elements

– the Jovian planets are large, have a low density, and are composed of gases and frozen compounds

• Slow rotation of the Sun

• Interplanetary material

– existence and location of asteroid belt

– distribution of interplanetary dust

Page 17: Solar system & planets

Meteorites - Visitors from Outer Space

– Stones - composed of iron and magnesium silicates, about 93% of all meteorites

– Irons - composed of iron and nickel alloys

– Stony-Irons - nearly equal amounts of iron and nickel and silicate minerals

• Meteorites are believed to be pieces of material that originated in the formation of the Solar System about 4.6 billion years ago

Page 18: Solar system & planets

THANK YOU