What do the following have in common?

Why Bother??? Exciting subject filled with new discoveries! Affects our every day lives! Mind blowing ideas that challenge our way of thinking! The wave of the future!

Preview Chapter The Cosmic Landscape

A Few Definitions moon or satellite: a body orbiting a planet.

A Few Definitions planet: a celestial body that is in orbit around the sun, has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a... nearly round shape, and has cleared the neighborhood around its orbit.

A Few Definitions star: a massive gaseous body held together by gravity and generally emitting light by nuclear reactions.

A Few Definitions solar-system: A collection of celestial objects (e.g. planets, comets, asteroids) orbiting around a common star.

A Few Definitions galaxy: A collection of stars, gas, dust, and dark matter held together by their mutual gravity.

A Few Definitions Universe: Consists of everything around us Includes Everything!

Concept Question Which one of the following is listed in the correct order from smallest to largest in size? A) star, planet, solar-system, galaxy, Universe B) planet, star, solar-system, Universe, galaxy C) star, planet, galaxy, solar-system, Universe D) planet, star, solar-system, galaxy, Universe

Scientific Method observe hypothesize test modify,reject,or theorize

Mystery Image

Science and PseudoScience

Astrology or Astronomy? Uses the positions of planets to predict human behavior Is a branch of Physics Uses the scientific method to interpret observations Is considered a pseudoscience A detailed study of all the celestial bodies in the Universe, including planets, moons, stars, galaxies, etc. Associates the signs of the zodiac with personality traits

Timeline of the Universe

Scientific Notation express very small or very large numbers in powers of ten Format: .  X 10  1.0= 1.0 X 10 0 (10 0 ) 100.0= 1.0 X 10 2 (10 2 ) 1,000.0= 1.0 X 10 3 (10 3 ) 10,000.0= 1.0 X 10 4 (10 4 ) 100,000.00= 1.0 X 10 5 (10 05 ) 0.1= 1.0 X (10 -1 ) 0.01= 1.0 X (10 -2 ) 0.001= 1.0 X (10 -3 ) = 1.0 X (10 -4 ) = 1.0 X (10 -5 )

Scientific Notation Examples: Average Distance from the Earth to the Sun: 149,600,000.0 km  X 10 8 km Mass of ant: g  4 X10 -3 g

Concept Question Write in scientific notation A) 3.15 X B) 3.15 X 10 6 C) X10 6 D) X 10 -6

Concept Question Write 7.89 X in regular format A) B) C) D)

Astronomical Units 1 A.U. = 1.5 X 10 8 km Average Distance from the Earth to the Sun  Astronomical Unit Distance that light travels in a year  Light Year speed of light in a vacuum: c = 3 x10 5 km/s (186,000 mi/s) so one light second: 3x10 5 km and one light year: 9.46x10 12 km more practical to use

Looking Backwards in Time on a planet orbitting a distant star 70 years old here on Earth 70 years old 55 light years away 15 years old 68 light years away 2 years old Because of the finite speed of light, we are able to look backwards in time!!!

Astronomical Distance Scales are Astronomical! Alpha Centauri: 4.2 light years away Andromeda Galaxy: 2.4 million light years away Galaxies in the Hubble Deep Field: as far as billions of light years away The Sun: 8.3 light minutes away The finite speed of light gives us a fossil record of the history of the Universe!!!! The Moon: 1.3 light seconds away

Astronomical Distance Scales are Astronomical!