Part 1 Earth in the Universe

Name ______Date ______

Astronomy Notes Part-1

Part 1 – Earth in the Universe

I. The Big Bang Theory  The ______started with a concentrated area of ______and energy.  ______billion years ago.  Then, it ______and has been ______ever since.  Matter began to ______together forming ______and ______.  The universe continued to expand and is still ______today.

II. Universe Expansion  How do we know the universe is expanding?  Pg. ___ in the ESRT shows the ______spectrum.  Notice that in the ______spectrum there are all the colors of the ______.  When looking at the visible spectrum ______are shifted either to the ______end (shorter wave) or the _____ end (longer wave).  This shift in wavelengths is called the ______.  If they are shifted toward ______, they are moving ______you.  If they are shifted toward ______, they are coming ______you.  When scientists look at the universe, they see a ______. This proves it is moving ______from us, thus, expanding!

III. Galaxies  A galaxy is a collection of billions of ______and _____ and ______.  Our solar system is part of the ______.  The Milky Way is a ______- ______galaxy. IV. Stars  A star is usually a large ball of ______held together by ______.  Energy is produced by ______- combination of ______of smaller elements to form nuclei of larger elements.

Use Star Chart on Page 15 of ESRT to answer questions

1. What is the most massive star on the chart? ______

2. What is the temperature and luminosity of the Sun? ______and ______

3. What group is a star in during a late stage? ______

4. What is the temperature and luminosity of Betelguese? ______and ______

5. What color would a star be if it was 15,000ºK? ______

6. What group of star is Albebaran in? ______

7. What temperature and color is Proxima Centauri? ______and ______

8. Massive stars are (more / less) luminous. (Circle one)

9. Name a White Dwarf star. ______

10. What stage are Main Sequence stars in? ______V. Our Solar System  The ______is the ______and all objects that ______the sun under its ______influence.  Our solar system has 1 sun and 8 ______.

Using the data table on page 15 of your ESRT, answer the following questions.

1. What is the period of rotation of Mercury? ______

2. What is a year on Mars?______

3. Which planet has the most eccentric orbit? ______

4. Which has the least eccentric orbit? ______

5. What is the diameter of Jupiter?______

6. What is a day on Saturn?______

7. Which planet has the longest period of rotation?______The shortest?______

8. Which planet is the most dense?______The least?______

9. How far from the sun is Venus?______

10. How far from Earth is our Moon?______

11. What is the mass of Neptune ?______

12. What is the radius of Saturn?______VI. Eccentricity and Ellipse  An ______is an oval shape.  Earth’s ______around the sun is an ellipse.  Within an ellipse, there are two ______points called ______.  In our solar system, the ____ is ______ONE of those foci.

An ellipse is an example of a “conic section”. Circles and hyperbolas are others. All are possible forms for orbits.

You can make an ellipse with 2 tacks and a string. The tacks are the “foci”, and if you put them further apart, the ellipse is more “eccentric” (one tack makes a circle).

 The ______of ______or “ovalness” of an ellipse is measured by ______.  This formula is on page ___ of your ESRT!!  The more ______the orbit is, the more ______it is, or the higher the eccentricity.

Increasing Eccentricity  Calculating Eccentricity:

Major Axis

Foci 1 Foci 2

 When you measure those 2 distances and calculate them, you will ______get higher than

 The closer to 1 you are, the ______oval or eccentric the orbit.

 The closer to 0 you are, the ______oval or eccentric the orbit.

VII. Gravitational Force

 The ______2 objects are to each other, the ______the ______pull

between them.

 Therefore, during the ______- when Earth is ______to the sun, there is a

______pull between it and the sun.

 This makes the Earth ______a bit in its ______around the sun during that time.

Perihelion Aphelion 1. Write the formula for eccentricity below:

2. Calculate the eccentricity of the ellipse. X X Distance between foci: ______

Distance of major axis: ______

Eccentricity= ______

3. Calculate the eccentricity of the ellipse. Distance between foci: ______

Distance of major axis: ______Eccentricity= ______X X

4. What is the minimum value that eccentricity can be? ______

5. What is the maximum value that eccentricity can be? ______