Astronomy Ch 6

Front 1

The nebular theory of the origin of the solar system was proposed by

Back 1

Laplace.

Front 2

The passing star mechanism of the origin of the solar system was proposed by

Back 2

Buffon.

Front 3

Why do astronomers believe that the angular momentum problem is no longer an objection to the solar nebula problem?

Back 3

The sun's magnetic field interacted with gas leaving the nebula and slowed the sun's rotation.

Front 4

Which one supports the solar nebula theory of the origin of the solar system?

Back 4

Disks are common around young stars.

Front 5

The oldest rocks found on Earth are about ____ years old.

Back 5

4.4 billion

Front 6

Which of the following is not a characteristic of the terrestrial planets?

Back 6

low average density

Front 7

The age of the solar system is believed to be approximately 4.6 billions years old based on the data from

Back 7

samples of lunar rocks. samples of earth rocks. samples of meteorites.

Front 8

In observations, ____ has a heavy element core, and a deep atmosphere made mostly of hydrogen.

Back 8

Uranus

Front 9

The condensation sequence suggests that ____ should condense closest to the sun.

Back 9

metals and metal oxides

Front 10

Condensation in the solar nebula probably led to the formation of

Back 10

icy grains beyond the present orbit of Jupiter. metallic grains near the present orbit of Mercury. silicate grains near the present orbit of Earth.

Front 11

Protoplanets of the Jovian planets could have grown very hot from

Back 11

the infall of material at high velocity.

Front 12

The planets all lie in nearly the same plane resulting in a disk-like structure for the solar system. This disk-like structure is believed to exist because

Back 12

the original solar nebulae had a disk-like structure.

Front 13

Which one of the following objects is most like the planetesimals that formed in the solar nebular?

Back 13

asteroids

Front 14

The large planetesimals would have grown faster than the smaller planetesimals because

Back 14

their stronger gravity would pull in more material.

Front 15

Accretion among the grains in the solar nebula would have been aided by

Back 15

static electricity.

Front 16

If a star is found with five planets orbiting it, which of the planets would be expected to have the greatest uncompressed density if the system was formed by a process like that described in the solar nebula theory?

Back 16

the one closest to the star

Front 17

The current atmosphere of Earth is believed to be

Back 17

composed of gases that were baked from the rocks sometime after the planet formed.

Front 18

The discovery that Jovian-like planets are common around other stars and that gas and dust is swept out of the solar neighborhood fairly early in the formation of a star suggests that

Back 18

the Jovians may have formed directly, without the core accretion phase.

Front 19

On a photograph of the moon, the moon measures 30 cm in diameter, and a small crater measures 0.2 cm. The moon's physical diameter is 1738 km. What is the physical diameter of the small crater?

Back 19

about 12 km

Front 20

Once a terrestrial planet had formed from a large number of planetesimals, heat from ____ could have melted it and allowed it to differentiate into a dense metallic core and a lower density crust.

Back 20

radioactive decay

Front 21

A future news release might report that a new planet has been found around a star very similar to our sun. This newly discovered planet is claimed to have a mass 40 times that of Earth and is located nearly 25 AU from the star it orbits. Which of the following would be a reasonable prediction about this planet?

I.The planet will probably have a mean density of around 5 g/cm3.

II.The planet will probably have a radius of around five to ten times greater than Earth's.

III.The planet will probably have several satellites.

IV.The planet will probably have a composition that is mostly hydrogen and helium.

Back 21

II, III, & IV

Front 22

Most planets thus far discovered around other stars were found by

Back 22

varying Doppler shifts of the stars.

Front 23

Planets are thought to be forming today in ____ around stars.

Back 23

hot disks

Front 24

What observation made of other stars seems to suggest the solar nebula hypothesis is correct?

Back 24

Young stars are found to have hot disks that surround them.

Front 25

Venus is often called Earth's sister planet because it is similar to the Earth in terms of

Back 25

mass. size. density

Front 26

Compared to the terrestrial planets, Jovian planets

Back 26

have a much larger diameter.

Front 27

The asteroid belt is found between which two planets?

Back 27

Mars and Jupiter

Front 28

If the catastrophic theory of the formation of the solar system is correct then we should expect

Back 28

to find a very few number of planetary systems like our own.

Front 29

How is radioactive dating used to determine the age of an object?

Back 29

The amounts of radioactive and decay material are compared to its half-life to determine age.

Front 30

How is the presence of space debris accounted for by solar system models?

Back 30

Space debris was formed by the collision of objects after the planets formed.