ASTR 100: Survey of Astronomy "We are explorers. Our curiosity propels us to push the frontiers of human possibility and imagination. This is the core of NASA's mission - We dare to explore."       - Michael D. Griffin         Former NASA Administrator         April, 2008 “Somewhere, something incredible is waiting to be known.” - Carl Sagan Astronomer

ASTR 100 Survey of Astronomy Instructor: Tracy Furutani (tfurutan@northseattle.edu) Textbook (required): Astrophysics is Easy! by Michael Inglis Course website: http://facweb.northseattle.edu/tfurutan then click on the Astronomy 100 link

Course Expectations High School Science and Math Skills Ability to use Basic Mathematical Techniques: (Algebra, Geometry, and Scientific Notation, Unit Conversion) Basic writing (referencing, researching, word processing…) Computer Literacy: (Web resources)

Assignments Exercises: In any sane world, these would be called “labs”. Hands-on lab to reinforce lecture topics. Also, time will be set aside to teach problem solving techniques and review lecture material. Poster Project: Visual presentation of a solar system exploration-related topic. Handout will follow. Includes the writing of an abstract (summary) prior to the presentation. Group Projects: One at the beginning of the quarter, one at the end. Will require working in groups of three or four, then some research, writing and designing, then a presentation to the class.

Course Objectives Explore the following topics: inventory of space, astronomical distances, forces that govern matter, basics of light and matter (spectroscopy), astronomical instrumentation, structure and energy source of the sun and other stars, stellar birth, life and death, galactic structure and classification, large scale structure of the universe, fate of the universe. Learn basic problem solving techniques. Learn basic observing and experimental techniques.

Some things we will discuss:

Some things we will discuss:

Some things we will discuss:

Why do we have seasons on earth? Change of earth’s distance from the sun Tilt of earth’s rotation axis relative to its orbit Greenhouse effect

Seasons

Will a human set foot on Mars in your lifetime? Yes No

Perspective The Earth was small, light blue, and so touchingly alone, our home that must be defended like a holy relic. The Earth was absolutely round. I believe I never knew what the word round meant until I saw Earth from space. - Aleksei Leonov, USSR

Perspective It suddenly struck me that that tiny pea, pretty and blue, was the Earth. I put up my thumb and shut one eye, and my thumb blotted out the planet Earth. I didn't feel like a giant. I felt very, very small. — Neil Armstrong (Apollo XI) The view of the Earth from the Moon fascinated me—a small disk, 240,000 miles away. . . . Raging nationalistic interests, famines, wars, pestilence don't show from that distance. — Frank Borman (Apollo VIII)

Math Review

Scientific Notation: Scientific notation is a shorthand way of writing and multiplying large (and small) numbers. 1,000,000,000,000 1012 terra (T) (trillions) 1,000,000,000 109 giga (G) (billions) 1,000,000 106 mega (M) (millions) 1000 103 kilo (k) (thousands) 1 100 unity 0.01 10-2 centi (c) (hundredth) 0.001 10-3 milli (m) (thousandth) 0.000001 10-6 micro () (millionth) 0.000000001 10-9 nano (n) (billionth)

Using Scientific Notation: To do numbers that are not divisible by ten, we multiply by an exponential number. 4,275,000,000 = 4.275 x 1,000,000,000 = 4.275 x 109 0.000374 = 3.74 x 0.0001 = 3.74 x 10-4

Using Scientific Notation: To multiply numbers using scientific notation, we add the exponents. 103 x 10-9 = 10(3) + (- 9) = 10-6 102 x 105 = 10(2) + (5) = 107 To divide numbers using scientific notation, we subtract the exponents. = 10(3) - (- 9) = 1012 = 10(2) - (5) = 10-3

Using Scientific Notation: To raise a number to a power, we multiply the exponents To changing from division to multiplication, we change the sign of the exponent

Using Scientific Notation: To add or subtract numbers using scientific notation, we work in front of the exponents, but they must have the same exponent. 3.0 x102 + 2.6 x 105 = 0.003 x 105 + 2.6 x 105 = 2.603 x105 1.0 x105 - 7.0 x 102= 1.0 x105 - 0.007 x105 = 0.993 x105

Scientific Notation /Units Example 1 How long does light take to travel from the visible surface of the Sun to the Earth? Distance from Sun to Earth D = 150,000,000 km This is also known as one astronomical unit (AU) In scientific notation D = 1.5  108 km

Scientific Notation /Units Example 1 How long does light take to travel from the visible surface of the Sun to the Earth? There are 1000 m = 103 m = 1 km: Hence, in meters:

Scientific Notation/Units Example 1 How long does light take to travel from the visible surface of the Sun to the Earth? The speed of light c = 3 x 108 m/s OR

Scientific Notation/Units Example 1 How long does light take to travel from the visible surface of the Sun to the Earth?

Scientific Notation/Units Example 2 Density of Water Density is mass per volume For water: 1 gram / centimeter3 (1g/cm3) What is this in kilograms / meters3 ?