© 2011 Pearson Education, Inc. Chapter 1 Astronomy Today 7th Edition Chaisson/McMillan

© 2011 Pearson Education, Inc. Charting the Heavens 1 Reading pg. 3-8

© 2011 Pearson Education, Inc. Our place in the Universe Constellations

© 2011 Pearson Education, Inc.

1.1 Our Place in Space Earth is average—we don’t occupy any special place in the universe Universe: totality of all space, time, matter, and energy

© 2011 Pearson Education, Inc. 1.1 Our Place in Space Discuss with a partner, What is Astronomy? Scales are very large: What unit do we measure distances in space in?

© 2011 Pearson Education, Inc. 1.1 Our Place in Space Astronomy: study of the universe Scales are very large: measure in light-years, the distance light travels in a year—about 10 trillion km

© 2011 Pearson Education, Inc. How fast does light travel in one second? a.3 x10 5 km./sec b. 300,000 km./sec c. 30,000 km. sec d. 3,000 km/sec

© 2011 Pearson Education, Inc. How fast does light travel in one second? a.3 x10 5 km./sec b. 300,000 km./sec

Let’s define Light Year A unit of interstellar distance, defined as the distance light travels in a period of one year. The speed of light is constant, at about 300,000 km per second or 9.5 trillion km/ year: From an Earthbound perspective, this is a vast distance - our entire Solar System, out to the orbit of Pluto, is only one eight-hundredth of a light year across.

© 2011 Pearson Education, Inc. Our Place in Space What is this object? What is the name of our group? Share your answer with your elbow partner.

© 2011 Pearson Education, Inc. Our Place in Space This galaxy is about 100,000 light-years across. A typical galaxy is a collection of a hundred billion stars, each separated by vast regions of nearly empty space. Our Sun is an undistinguished star near the edge of similar galaxy, called the Milky Way.

© 2011 Pearson Education, Inc. Simplest observation: Look at the night sky How many stars do you think can be seen with the naked eye on a clear night? Write your answer down on the white board and hold it up?

© 2011 Pearson Education, Inc. Simplest observation: Look at the night sky About 3000 stars visible at any one time; distributed randomly but human brain tends to find patterns

© 2011 Pearson Education, Inc. Constellations Group stars into constellations: Figures having meaning to those doing the grouping Useful: Polaris, which is almost due north Useless: Astrology, which makes predictions about individuals based on the star patterns at their birth

© 2011 Pearson Education, Inc. Turn to an elbow partner, What are the differences between Astrology vs. Astronomy? AstronomyAstrology

© 2011 Pearson Education, Inc. Turn to an elbow partner, What are the differences between Astrology vs. Astronomy? Astronomy The study of objects and phenomena beyond the Earth’s Atmosphere Goal: to understand the physics of the universe Astrology The belief that the position of the heavenly bodies and celestial events correlate with earthly events and human affairs

© 2011 Pearson Education, Inc. Constellation Myth project The purpose behind this project is to create a poster for a constellation that will instruct others on your chosen constellation. There are 88 constellations to chose from. Please pick from one of the IAU constellations. If your are interested in constellation from other cultures, this would be a great extra credit opportunity.

© 2011 Pearson Education, Inc. Constellation Project Poster requirements 1.Typed report containing scientific requirement and myth must be displayed on the report 2.Constellation visual-must cut out holes in black construction paper to represent stars. Hole size must be representative of the difference sizes of stars in your constellation 3.Full color artwork of your constellation incorporated into the mythical figure

© 2011 Pearson Education, Inc. There will be a list coming around of the constellations Please sign up for constellation that has not been chosen.

© 2011 Pearson Education, Inc.

Stars that appear close in the sky may not actually be close in space