U2 Discovering New Worlds

Question 1

red shift

Answer 1

the observation that as an object moves away from us, its wavelength is stretched out and moves towards the red end of the spectrum

Question 2

cosmic background radiation

Answer 2

The “afterglow” or radiation left over from the Big Bang; found throughout the universe

Question 3

comet

Answer 3

chunk of rock and ice orbiting from the outer solar system to near the Sun

Question 4

meteor

Answer 4

streak of light seen when a space rock enter’s Earth’s atmosphere and starts burning up (sometimes referred to as “shooting stars”); if it doesn’t completely burn up in the atmosphere and actually hits the Earth it is called a meteorite

Question 5

asteroid

Answer 5

rocky/metallic object orbiting the Sun between Mars and Jupiter in the “asteroid belt”; these can leave this orbit and move through the universe

Question 6

supernova

Answer 6

when a very large star dies and explodes

Question 7

gravity

Answer 7

a force between objects that pulls them together; will increase with mass and decrease with distance

Question 8

nuclear fusion

Answer 8

the combining of 2 lighter elements (hydrogen) to form a heavier element (helium); it is the source of power for stars and release a lot of energy

Question 9

exoplanet

Answer 9

a planet outside our solar system

Question 10

revolution

Answer 10

moving around an object in an orbit (such as the Earth revolving around the Sun)

Question 11

rotation

Answer 11

spinning on an axis

Question 12

luminosity

Answer 12

the brightness of a star

Question 13

eccentricity

Answer 13

a measurement that tells the shape of an orbit (distance between foci/length of the major axis); the closer the measurement is to 1 the flatter the orbit and the close to 0 the more circular the orbit

Question 14

ellipse

Answer 14

an oval shape

Question 15

main sequence

Answer 15

the most stable time for a star; it spends most of its life in this stage

Question 16

life cycle of a star

Answer 16

the predictable stages of a star’s life

Question 17

white dwarf

Answer 17

the final stage for our Sun; dead star

Question 18

black hole

Answer 18

created when a very large star explodes

Question 19

neutron star

Answer 19

when a very large star explodes but is not big enough to form a black hole

Question 20

nebula

Answer 20

gases in space that appear to form a cloud; will be the leftovers (remnants) and a star explosion (supernova); may eventually contract to form a star

Question 21

What galaxy are we in?

Answer 21

Milky Way

Question 22

star system

Answer 22

the planets and objects that orbit a star; the star system is named after the star Ex: Betelgeuse System, Solar System, Polaris System

Question 23

major axis

Answer 23

the diameter of an ellipse at its widest point

Question 24

aphelion

Answer 24

the part of an orbit where the object is farthest away from what it is orbiting around

Question 25

perihelion

Answer 25

the part of an orbit where the object is closest to what it is orbiting around

Question 26

terrestrial planets

Answer 26

planets that have a rocky surface; in our solar system they are located closest to the Sun: Mercury, Venus, Earth, and Mars

Question 27

jovian planets

Answer 27

the gas giants; in our solar system they are located farthest from the Sun: Jupiter, Saturn, Uranus, Neptune

Question 28

compared to the solar system, the universe is

Answer 28

older, larger, and contains more stars

Question 29

What is located at one of the foci of an orbit?

Answer 29

the star the object is orbiting around

Question 30

When did our Solar System form?

Answer 30

4.6 billion years ago

Question 31

When did Venus form?

Answer 31

4.6 billion years ago

Question 32

Compared to the terrestrial planets, the Jovian planets are

Answer 32

less dense and more mass

Question 33

What are the Jovian planets?

Answer 33

Jupiter, Saturn, Uranus, and Neptune

Question 34

What are the terrestrial planets?

Answer 34

Mercury, Venus, Earth, and Mars

Question 35

Explain why Pluto and its five moons are considered to be part of our solar system

Answer 35

— Pluto and its five moons revolve around the Sun. — All go around/orbit the Sun.

Question 36

Identify the name of Pluto's moon that most likely has an orbit farthest from Pluto. Explain how the data indicate that this moon's orbit has the greatest distance from Pluto.

Answer 36

— Hydra has the longest period of revolution. — As a moon's distance from Pluto increases, the time to make one revolution also increases. — Hydra travels the greatest distance in its orbit because it has the longest period of revolution.

Question 37

Describe the shape of the orbit of Pluto and the orbits of its five moons.

Answer 37

— elliptical — The orbits are eccentric. — The orbits are nearly, but not perfectly, circular. — oval — Pluto's orbit is elliptical, and the moons of Pluto have a more nearly circular orbit.

Question 38

Which is a possible surface temperature of this star at point 2? (see figure): A) 3000 K B) 5000 K C) 7000 K D) 10,000 K

Answer 38

C

Question 39

Between points 1 and 3, this star is visible to observers on Earth because it emits light energy. This energy is released by the process of nuclear fusion when: A) dust collides with the star B) dust is broken apart by radiation C) lighter elements combine to form heavier elements D) heavier elements are broken down to form lighter elements

Answer 39

C