Part 1 – Earth in the Universe

Astr nomy

The Big Bang Video

• The universe started with a concentrated area of matter and energy.

• 15-20 billion years ago.

• Then, it exploded and has been expanding ever since.

•Matter began to clump together forming stars and galaxies.

•The universe continued to expand and is still expanding today.

Our Expanding Universe Video

Regents Question

Which celestial feature is largest in actual size?

(1) the Moon (2) the Sun(3) Jupiter (4) the Milky Way

Answer is…4

• How do we know the universe is expanding?

• Pg. 14 in the ESRT shows the electromagnetic spectrum.

• Notice that in the visible spectrum there are all the colors of the rainbow.

Please answer the questions on the Electromagnetic spectrum ½ sheet.

• When looking at the visible spectrum wavelengths are shifted either to the blue end (shorter wave) or the red end (longer wave).

• This shift in wavelengths is called the Doppler Effect.

• If they are shifted towards red, they are moving away from you.

• If they are shifted toward blue, they are coming towards you.

•When scientists look at the universe, they see a red shift. This proves it is moving away from us, thus, expanding!

A Quick look at the Doppler Affect Using a police car

Another look at the Doppler Affect using sound

Light from galaxies moving awayEarth Science

Rocks

Notice the shift towards red

Light from galaxies moving toward usEarth Science

Rocks

Notice the shift towards blue.

• A galaxy is a collection of billions of stars and gas and dust.

• Our solar system is part of the Milky Way Galaxy.

• The Milky Way is a spiral-shaped galaxy.

Regents Question

The Milky Way Galaxy is best described as

(1) elliptical

(2) circular

(3) irregular

(4) Spiral

Answer is…

4

• A star is usually a large ball of gas held together by gravity.

• Energy is produced by nuclear fusion – combination of nuclei of smaller elements to form nuclei of larger elements.

Earth Science

Rock

Regents Question

Which star color indicates the hottest star surface temperature?

(1) blue

(2) yellow

(3) white

(4) Red

The good news!! This is all for free on pg. 15 of the ESRT!

Regents Question

Which star color indicates the hottest star surface temperature?

(1) blue

(2) yellow

(3) white

(4) Red

Answer is…

1

Regents Question

In the main sequence, compared to the surface temperature and luminosity of massive stars, the smaller stars are

(1) hotter and less luminous(2) hotter and more luminous(3) cooler and less luminous(4) cooler and more luminousAnswer is…3

Life and Death of a Star Video Clip

Take out ESRT- Page 15

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? ________________________________

DENEB

5,600 ºK

Luminosity = 1

White Dwarfs

Page 15

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? ________________________________Giants

Blue White

3300ºK

200,000

Page 15

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? _______

Procyon B or Eridani B

Early

2800ºK Red

• The solar system is the sun and all objects that orbit the sun under its gravitational influence.

• Our solar system has 1 sun and 8 planets.

Regents Question

The Sun’s position in space is best described as the approximate center of

(1) a constellation

(2) the universe

(3) the Milky Way galaxy

(4) our solar system

Answer is…

4

Regents QuestionCompared to Earth’s solar system,

the universe is inferred to be

(1) younger and larger (2) older and larger(3) younger and smaller (4) older and smallerAnswer is…2

Pluto?New Chart in your ESRT…

Sorry Pluto…

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?__________________________________________

59d

687 d

Mercury

Venus

142,984 km

10 h 14 min

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?_______________________________

Venus Jupiter

Earth Saturn

108.2 million km

0.386 million km

4,498.3 million km

60,268 km

Regents QuestionWhich event takes the most time?

(1) one revolution of Earth around the Sun

(2) one revolution of Venus around the Sun

(3) one rotation of the Moon on its axis

(4) one rotation of Venus on its axis

Answer is…1

• An ellipse is an oval shape.

• Earth’s orbit around the sun is an ellipse.

• Within an ellipse, there are two fixed points called foci.

• In our solar system, the sun is ALWAYS ONE of those foci.

•The degree of flatness or “ovalness” of an ellipse is measured by eccentricity.

•This formula is on page 1 of your ESRT!

• The more oval the orbit is, the more eccentric it is, or the higher the eccentricity.

Increasing Eccentricity

• Calculating Eccentricity:

X X

Major Axis

Foci 1 Foci 2

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).

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

• Calculating Eccentricity:

• When you measure those 2 distances and calculate them, you will NEVER get higher than 1!!

• The closer to 1 you are the MORE oval or eccentric the orbit.

• The closer to 0 you are the LESS oval or eccentric the orbit.

Regents Question

Which planet’s orbit around the Sun is most nearly circular? (ESRT 15)

(1) Mercury

(2) Pluto

(3) Neptune

(4) Venus

Answer is…

4

No More Pluto

• The closer 2 objects are to each other, the greater the gravitational pull between them.

• Therefore, during the perihelion – when Earth is closer to the sun, there is a greater gravitational pull between it and the sun.

• This makes the Earth speed up a bit in its orbit around the sun during that time.

Perihelion Aphelion

Earth Science

Rocks

What do you notice about the planets orbital velocity?

Aphelion Perihelion

Planets move quicker Planets move quicker the closer they are to the closer they are to

the Sunthe Sun

Kepler’s Second Law

Regents Question

Compared to Neptune, Mercury moves more rapidly in its orbit because Mercury

(1) is larger

(2) is more dense

(3) is closer to the Sun

(4) has a more elliptical orbit

Answer is…

3

Write the formula for eccentricity below:

Calculate the eccentricity of the ellipse. Distance between foci: ______________ Length of major axis: ______________Eccentricity= ______________

X X

Page 1 of ESRT’s

length of Major Axis

Distance between foci

8.8cm

6.4cm

.72

Calculate the eccentricity of the ellipse. Distance between foci: ______________ Length of major axis: ______________Eccentricity= ______________

X X

Length of Major Axis

Distance between foci

5.4cm

1.3cm

.24

What is the minimum value that eccentricity can be? ________0

.99

What is the maximum value that

eccentricity can be? _______

Doesn’t a circle look like a zero????

The more eccentric the more stretched out until you get a straight line

Look the # one.