Lesson 1

Question 1

About where is our solar system located within the Milky Way Galaxy?

Answer 1

About two-thirds of the way from the center of the galaxy to the outskirts of the galactic disk

Question 2

Modern telescopes are capable of seeing bright galaxies up to about

Answer 2

10 billion light-years away

Question 3

Suppose we imagine the Sun to be about the size of a grapefruit. How big an area would be the orbits of the eight planets of the solar system cover?

Answer 3

The size of a typical campus

Question 4

How are galaxies important to our existence

Answer 4

Galaxies recycle heavy elements produced in stars into future generation of stars.

Question 5

What is nuclear fusion

Answer 5

The process of combining lightweight nuclei to make heavier nuclei

Question 6

One light-hour is the distance that light travels in an hour. How far is this, in kilometres?

Answer 6

1.08 billion km

Question 7

Suppose we imagine the Sun to be about the size of a grapefruit. Which of the following describes the size and distance of Earth on the same scale?

Answer 7

Earth is the size of a point about 15 meters away from the Suns.

Question 8

On the 1-to-10 billion scale, about how far is it to the nearest stars besides the Sun?

Answer 8

4,400 km

Question 9

Suppose we imagine the Sun to be about the size of a grapefruit. How far are the nearest stars (the three stars of Alpha Centauri)

Answer 9

2,500 miles

Question 10

If we use 1 mm to represent 1 light-year, how large in diameter is the Milky Way Galaxy?

Answer 10

100 meters

Question 11

If you represented each star by a grain of sand, how much sand would it take to represent all the stars in the universe?

Answer 11

more than all the sand on all the beaches on Earth

Question 12

On a cosmic calendar, in which the history of the universe is compressed into one year, how long is the average human life span?

Answer 12

0.2 second

Question 13

Approximately how fast are you moving with the rotation of Earth

Answer 13

1,300 km/hr

Question 14

How long does it take our solar system to complete one orbit around the Milky Way Galaxy?

Answer 14

230 million years

Question 15

Which of the following correctly lists speeds from slowest to fastest?

Answer 15

Earth’s speed of rotation on its axis, Earth’s speed of revolution about the Sun, typical speeds of stars in the local solar neighborhood relative to us, the speed of our solar system orbiting the center of the Milky Way Galaxy, the speeds of very distant galaxies relative to us

Question 16

Most of the mass in the Milky Way Galaxy is located

Answer 16

In the halo (above/below the disk)

Question 17

Suppose we make a scale model of our solar system, with the Sun the size of a grapefruit. Which of the following best describes what the planets would look like?

Answer 17

The planets are all much smaller than the Sun. Four planets are within about 20 meters of the Sun, while the rest planets are spread much farther apart.

Question 18

How do the speeds at which we are moving with Earth’s rotation and orbit compare to the speeds of more familiar objects?

Answer 18

Earth’s rotation carries most people around the axis faster than a commercial jet travels, and Earth’s orbit carries us around the Sun faster than the Space Shuttle orbits Earth.