Astronomy 2

Question 1

Where are the asteroids located?

Answer 1

Most asteroids have orbits between the orbits of Mars and Jupiter, but there are gaps caused by resonances with Jupiter.

Question 2

Only the few largest asteroids are found to be spherical. Why is this?

Answer 2

Self-gravity for the most massive asteroids was sufficient to pull them to this shape during their early history.

Question 3

A meteoroid is the name for a solid particle that

Answer 3

is drifting around in space.

Question 4

Interplanetary material

Answer 4

falls on Earth at the rate of almost a hundred tons per day, mostly as cosmic dust.

Question 5

Most comet nuclei are believed to be

Answer 5

chunks of dirty ice left over from the formation of the solar system.

Question 6

A comet’s tail points

Answer 6

away from the Sun regardless of the comet’s motion.

Question 7

The orbits of comets are

Answer 7

randomly oriented in the solar system and can extend far beyond the orbit of Pluto.

Question 8

What is the Kuiper belt?

Answer 8

a relatively flat distribution of objects in the plane of the ecliptic, extending from around the orbit of Pluto out to about 50 AU from the Sun

Question 9

The Oort cloud is

Answer 9

an approximately spherical distribution of comets centered on the Sun, extending out to about 50,000 AU.

Question 10

A meteor shower occurs when

Answer 10

Earth passes through a swarm of dust particles in space.

Question 11

How was Uranus discovered?

Answer 11

by accident, by an astronomer conducting a sky survey

Question 12

Neptune was discovered by

Answer 12

the careful application of Newton’s laws to the motion of other planets.

Question 13

The major planet whose spin axis lies almost in its orbital plane is

Answer 13

Uranus

Question 14

What gives Uranus its blue-green coloration?

Answer 14

absorption of the red and yellow sunlight by methane gas

Question 15

The Great Dark Spot on Neptune

Answer 15

disappeared sometime between the Voyager 2 flyby and when the Hubble Space Telescope photographed Neptune in 1994.

Question 16

How do the densities of Jupiter, Saturn, Uranus, and Neptune compare?

Answer 16

Uranus and Neptune are more dense than Jupiter or Saturn.

Question 17

In what way do Uranus and Neptune differ from Jupiter and Saturn?

Answer 17

Hydrogen and helium make up a smaller fraction of the total mass of Uranus and Neptune.

Question 18

How were the rings of Neptune first discovered?

Answer 18

occultation of a star as the rings moved in front of it

Question 19

Triton, the giant moon of Neptune, differs from all other major moons of planets in that

Answer 19

it orbits in a retrograde way, opposite to the planet’s rotation.

Question 20

What future awaits Triton, the largest satellite of Neptune?

Answer 20

tidal breakup as it slowly spirals closer to Neptune

Question 21

The four giant moons of Jupiter were discovered by

Answer 21

Galileo.

Question 22

Which satellite of Jupiter is volcanically active?

Answer 22

Io

Question 23

Io would probably be less active geologically if

Answer 23

its orbit were circular.

Question 24

The most active volcanic object in the solar system is

Answer 24

Io, the inner Galilean moon of Jupiter.

Question 25

Jupiter's magnetic field is caused by

Answer 25

the planet's rapid rotation coupled with liquid metallic hydrogen in its interior.

Question 26

All of the following exist on Titan except

Answer 26

liquid water on the surface. (Rain, Nitrogen vapor and clouds=there)

Question 27

The largest satellite (moon) in our planetary system is

Answer 27

Ganymede, a moon of Jupiter.

Question 28

Titan is Saturn's largest satellite. It is unusual among all the planetary moons because of its

Answer 28

dense atmosphere.

Question 29

Extensive volcanic activity observed on Jupiter's satellite Io is caused by

Answer 29

tidal stresses from Jupiter and the other Galilean moons.

Question 30

Which of the planets fits the following description: “a solid, cool surface, with occasional dust clouds and a thin CO2 atmosphere”?

Answer 30

Mars

Question 31

Venus appears to be very bright in our skies at certain times because

Answer 31

it is relatively close to the Sun, Earth is close to it, and it is covered by very reflective clouds.

Question 32

Craters on Mercury appear to have been produced by

Answer 32

impacts from objects early in the planet's history.

Question 33

Phobos and Deimos are moons of which planet?

Answer 33

Mars

Question 34

The clouds in the atmosphere of Venus consist primarily of

Answer 34

droplets of H2SO4 or sulfuric acid.

Question 35

The most common surface features on Venus are

Answer 35

volcanoes and lava flows.

Question 36

Hot-spot volcanism is a process that

Answer 36

produces gigantic volcanoes on Venus and Mars but produces chains of smaller volcanoes on Earth (e.g., the Hawaiian Islands).

Question 38

The internal structure of Mercury is a

Answer 38

dense iron core taking up almost half of the volume of the planet and a rocky mantle surrounding the core.

Question 39

A major feature of the atmosphere of Mars is

Answer 39

occasional strong winds and dust storms.

Question 40

The polar caps on Mars are most likely made up of

Answer 40

water and CO2 ices.

Question 41

The rotation period of the Moon on its axis with respect to space (its absolute rotation) is

Answer 41

27.3 days, the sidereal revolution period.

Question 42

The Moon has

Answer 42

no measurable atmosphere or liquid water.

Question 43

Maria are

Answer 43

ancient lava floodplains.

Question 44

The mountain ranges on the Moon are

Answer 44

the walls of craters caused by impacts of large objects early in the geological history of the Moon.

Question 45

How many times have human beings landed on the Moon?

Answer 45

6

Question 46

The age of Moon rocks has been determined primarily by what method?

Answer 46

measurements of radioactive decay products

Question 47

How quickly is the Moon spiraling away from Earth?

Answer 47

a few centimeters per year

Question 48

One distinct difference between Earth and its neighboring planets, Venus and Mars, is the presence of

Answer 48

liquid water on its surface and water molecules chemically locked into rocks.

Question 49

Earth's mantle is composed largely of what chemical materials?

Answer 49

silicon-rich rocks and minerals

Question 50

Approximately how many tectonic plates make up Earth's surface?

Answer 50

~10

Question 51

What are the Van Allen belts?

Answer 51

Regions of high-energy charged particles in Earth's magnetosphere.

Question 52

The major layers of Earth's atmosphere from the surface upward in correct order are

Answer 52

troposphere, stratosphere, mesosphere, thermosphere.

Question 53

At the present time, the energy of the Sun is generated

Answer 53

in its central core only, by fusion of hydrogen nuclei.

Question 54

The total time that the Sun will spend converting hydrogen to helium in its core is

Answer 54

about 10 billion years (1010 years).

Question 55

The phrase “'hydrostatic equilibrium”' in the Sun refers to the

Answer 55

balance of gravity inward and gas pressure outward.

Question 56

Just outside the radiation zone lies the

Answer 56

convection zone.

Question 57

From the center outward, the order of the layers or parts of the Sun is

Answer 57

radiative zone, convection zone, photosphere, chromosphere, corona.

Question 58

What is the photosphere of the Sun?

Answer 58

the visible “surface” of the Sun

Question 59

Granulation on the surface of the Sun is caused by

Answer 59

convective currents carrying heat from beneath the surface.

Question 60

What is the corona on the Sun?

Answer 60

the Sun's outer atmosphere

Question 61

What is the solar wind?

Answer 61

the Sun's outer atmosphere streaming out into space

Question 62

At the present time, how many extrasolar planets have had confirmed discoveries?

Answer 62

thousands

Question 63

What is the astrometric method used in searches for planets orbiting stars other than the Sun?

Answer 63

a search for tiny wobbles in the position of the star due to the gravitational pull of a planet orbiting around it