ASTR 115: Stars and galaxies"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 115 – Stars and galaxies

Instructor: Tracy Furutani (tfurutan@northseattle.edu) Textbook (required): Astrophysics is Easy! by Michael Inglis

Course website: http://facweb.northseattle.edu/tfurutanthen click on the Astronomy 115 link

Note: This a hard-link integrated studies course with Barbara Goldner’s MATH 098 class. The classes run concurrently.

Course Expectations• Basic math skills (basic algebra, scientific notation,

unit conversion)

• Basic writing (referencing, researching, word processing)

• Computer literacy (using Web resources)

Assignments Labs: Hands-on exercises to reinforce lecture topics. Also, time will be

set aside to teach problem solving techniques and review relevant lecture material. May be done in groups or individually.

Poster Project: Visual presentation of the term project. Handout will follow. Includes the writing of an abstract (summary) prior to the presentation.

Homework: Roughly one assignment per week, to be done outside of class time, though you should ask questions related to the homework in class. May require some outside reading. Each person should turn in their own assignment.

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:

Some things we will discuss:

Why do we have seasons on earth?

1. Change of earth’s distance from the sun

2. Tilt of earth’s rotation axis relative to its orbit

3. Greenhouse effect 4. Mysterious alien

technology

Why do we have seasons on earth?

Seasons

Will a human set foot on Mars in your lifetime?

1. Yes2. 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

PerspectiveIt 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)

Perspective and Scale in Our Solar System

Our Local Inventory:What makes up our star system?

1) A single central star of spectral class “G2”, luminosity class V (yellow-dwarf, main sequence).2) Two sub-stellar giant planets (Jupiter & Saturn)

3) Two icy-gas hybrid planets (Uranus & Neptune)

All of the above planets have large systems of satellites; some are planet-sized: Io, Europa, Ganymede, Callisto, Titan, and

Triton)4) Four much smaller rocky planets. (Mercury, Venus, Earth, & Mars)5) Two areas of failed planetary debris

a) one rock-based (asteroid belt between Mars and Jupiter)

b) one ice-based (Kuiper Belt starting at Neptune’s orbit) .6) Several “dwarf planets” (e.g., Pluto)

7) An extended distribution of ejected or non-condensed debris (Oort Cloud)

Asteroid belt (rocks) between Mars and Jupiter

Icy Kuiper Belt Objects (KBOs) lie beyond Neptune’s orbit

Oort Cloud is well beyond Pluto, or Sedna, or Eris, or any other KBO

Solar System (Is this scale right?)

1. Yes2. No

Solar System (Is this scale right?)

Sun

Earth Venus

Mars

Mercury

Sun

Saturn

Jupiter

Uranus Neptun

e

Pluto Missoula

The Sun and the Solar System

Compared to the Sun, the planets are nearly inconsequential…..

1) The sun contains 99.9% of all the mass in the solar system (Jupiter has most of the remaining 0.1%)

2) The sun dominates energy (and light) production at all frequencies (except in radio waves where human activity is stronger!)

3) Solar energy largely determines the temperatures of every object in the solar system.

4) Material from the solar atmosphere is the dominant component of interplanetary space.

Any study of the solar system must start with the Sun…..

Sol

Uranus

Earth

Jupiter

Neptune

SaturnThe Sun dominates the solar system.

The places we are most interested in don’t add up to very much……

Earth Venus Mars

Ganymede Titan Mercury Callisto

Moon Io Europa Triton Pluto

Our Local Inventory:

Where to learn more?

www.nineplanets.org

www.earthsky.org