Chapter 4 - Space and Time Flashcards
How old is the earth?
4.56 billion years old
Why are the rocks on the moon so old?
Because the moon has no rock cycle
What are the innermost planets called? What are they? Describe them
They are called terrestrial planets, they are; small, rocky, metallic, and dense. The terrestrial planets are; Mercury, Venus, Earth, and Mars
What are the outer planets called? What are they? Describe them
They are called jovian planets, they are much larger, less dense and more gaseous than terrestrial planets. They jovian planets are; Jupiter, Saturn, Uranus, and Neptune
What is the largest known volcano in the solar system?
Olympus Mons
What is unique to the earth compared to the other planets?
Tectonic activity
What dominates 98% of the suns mass?
Hydrogen and helium
Why do seasons occur on earth?
Seasons occur on earth because of the tilt of the earth’s axis at 23.5 degrees that keeps the earth at a constant orientation as the planet revolves around the sun.
The northern hemisphere is pointed directly towards the sun during June and the southern hemisphere in December.
How many planets are in the solar system, list them by type.
There are 8 planets in the solar system.
Terrestrial - rocky, small, metallic and dense
- Mercury
- Venus
- Earth
- Mars
Jovial
- Jupiter
- Saturn
- Uranus
- Neptune
What is geocentric?
That everything used to revolve around earth, an idea once believed.
What is heliocentric?
Everything revolves around the sun
Name the 8 planets in order moving away from the sun
- Mercury
- Venus
- Earth
- Mars
- Jupiter
- Saturn
- Uranus
- Neptune
What is the nebular hypothesis?
The nebular hypothesis proposes that a huge swirling cloud of cosmic gas and dust (a nebula) formed the sun and planets
How did the nebular hypothesis work?
- gravity pulled the slower, swirling gas and dust inwards
- gas became hotter and denser
- temperature and pressure reached height for nuclear fusion which created the sun
- surrounding the sun was a flattened rotating disc of gas and dust
What explains the distinct materials of the terrestrial and jovial planets?
Distance from the sun and condensation temperatures
What 5 key factors lead to the evolution of terrestrial planets?
- Melting, impacts, and differentiation
- Volcanism
- Planatary mass
- Distance from the sun
- Biosphere
What is an indicator of high internal temperature?
Volcanism
What provides earth with a strong magnetic field?
It’s molten core
Which planets composition is remarkably similar to the sun?
Jupiter
How big is earths moon in relation to earth, how did it form?
Earth’s moon is 1/4 the size of earth and likely formed from a catastrophic collision.
Explain the collision that formed earth’s moon
- Earth runs into another growing planet called Theia
- Theia is destroyed along with a chunk of earths mantle which are blasted into orbit around earth
- The debris spreads itself into a ring and beings to clump together
- The larges clump attracts other fragments and begins forming the moon
What are asteroids and meterorites?
Subplanatary objects orbiting the sun that are commonly rocky and or metallic.
What are stars classified by?
Color and brightness.
Color
- indication of temperature
- blue = short wavelengths/hot
- red = long wavelengths/cool
What is the big bang?
The hypothesis that everything originated at one location in an explosion
What is relative age?
–refers to the order in which a sequence of past events occurred
What is numerical age?
–is the actual time, in years, when a specific event happened, calculated using radioactive decay
What is uniformitarianism?
“The presence is the key to the past”
Which is the smallest planet in the solar system?
a. venus
b. mercury
c. earth
d. mars
b. mercury
Jupiter and Saturn are so massive that their atmospheric gases never escaped; their atmospheres still maintain compositions very similar to the solar nebula from which they are formed.
True or False
True
Radiometric dating is possible if a rock contains a measurable amount of:
a. daughter isotopes
b. parent isotopes
c. parent or daughter isotopes
d. parent and daughter isotopes
d . parent and daughter isotopes
The model in which the sun is at the center of the solar system is called the
a. newtonian model
b. geocentric model
c. galilean model
d. helocentric model
d. helocentric model
Life on earth was able to develop primarily due to
a. the chemical composition of its rocks
b. a combination of its size and its distance from the sun
c. is distance from the sun
d. its size
b. a combination of its size and its distance from the sun
A solar system is comprised of eight planets. All of the planets (other than mercury and venus) have one or more moons. How many moons have been observed?
a. 10 known moons
b. 8 known moons
c. 170 known moons
d. 200 known moons
c . 170 known moons
(had to google, could be inaccurate)
Earth’s moon is a result of a comet captured within earth’s gravitational field
True or False
False
The main factors that influenced the evolution of the terrestrial planets shortly after their formation were impact cratering, volcanism, proximity to the sun, and the absence or presence of a biosphere
True or False
True
Because of the earth’s relatively small mass, our planet’s atmosphere is composed:
a. of the same percentages of gases that exist throughout the solar system
b. of a large amount of carbon dioxide
c. of gases similar to those of the jovian planets
d. of very little hydrogen and helium
The most widely accepted theory for the formation of the moon is the:
a. capture model, in which the moon formed in another part of the solar system and was captured by earth’s gravitational field
b. quaint idea that the moon is made of green cheese
c. giant impact model, in which material was ripped from the earth after an impact with a mars size object
d. co-formation model, in which the moon formed from a rotating disk of gas and dust around the earth.
c. giant impact model, in which material was ripped from the earth after an impact with a mars size object
What is the kuiper belt?
a. a vast repository for meteors
b. a vast repository for asteroids
c. the location of pluto’s orbit
d. a vast repository for comets
d . a vast repository for comets
The atmospheres of the jovian planets are made of primarily:
a. liquid metallic hydrogen
b. methane and ammonia
c. oxygen and nitrogen
d. hydrogen and helium
If pluto is not a planet (but rather a dwarf planet), then where do astronomers believe its point of origin?
a. a comet from the oort cloud
b. a moon from neptune
c. a comet from the kuiper belt
d. an asteroid from the asteroid belt
c. a comet from the kuiper belt
Numerical age is the actual time when a specific event happened
True or False
True
If the ages of the earth and the moon are nearly identical, as believed, why are most rocks found on the moon so much older than rocks found on earth?
a. the moon is older
b. age dating techniques are just too inaccurate to really know
c. unlike the earth, the moon as no atmosphere to weather rocks or plate tectonic activity to destroy rocks
d. none of the choices listed
c. unlike the earth, the moon as no atmosphere to weather rocks or plate tectonic activity to destroy rocks
According to the nebular hypothesis:
a. planets should rotate in the same direction as they revolve around the sun.
b. the hypothesis does not indicate direction or rotation or revolution
c. planets can rotate in any direction around the sun
d. planets should rotate one way and revolve the other way
b. the hypothesis does not indicate direction or rotation or revolution
We experience seasons due to the extreme changes of earth’s orbit around the sun
True or False
False
The age of the solar system is about 4.6 million years old
True or False
False
Differentiation is a process by which
a. the earth’s surface separated into continents and oceans
b. less dense materials sink and denser materials rise to the surface
c. none of the above
d. denser materials sink and less dense materials rise to the surface
d . denser materials sink and less dense materials rise to the surface
As the sun continues to age, the chemical composition of its core will change. Over time, it will contain a lower percentage of and a greater percentage of:
a. helium, hydrogen
b. oxygen, nitrogen
c. carbon, lead
d. hydrogen, helium
The principle of uniformitarianism states that the landscape of the earth formed via a series of sudden and catastrophic events in earth’s early history
True or False
False
The innermost planets in the solar system (Mercury, Venus, Earth, Mars) are large and gaseous.
True or False
False
If the earth had a 90 degree tilt rather than a 23.5 degree tilt, how many seasons would there be?
a. three (winter, spring, summer)
b. four (winter, spring summer, fall)
c. two (winter, summer)
d. one (little to no seasonal variation)
Venus unlike earth, mercury, mars spins rotates in a retrograde motion
True or False
True
Icy comets that were originally orbiting in the inner part of the solar system could have met which of several fates?
a. the loss of their icy constituents due to volatilization
b. all of the above
c. collision with a planet or planetesimal
d. being swept to the outer part of the solar system by a strong solar wind
b. all of the above
All of the objects in the solar system orbit around earth
True or false
False
Most of the exoplanets discovered thus far are
a. giant planets, most likely resembling jupiter
b. parts of planetary systems quite different than ours
c. small planets, most likely resembling earth
d. parts of planetary systems very similar to ours
The sun converts mass into energy by
a. fossil fuel burning
b. all of the above
c. nuclear fusion
d. nuclear fission
c. nuclear fusion
All of the terrestrial planets lost their primary atmospheres, but Earth, Mars, and Venus evolved and retained secondary atmospheres
True or False
True
The sun is massive enough to keep burning on the main sequence for another
a. 20 billion years
b. 5 billion years
c. 15 billion years
d. 10 billion years
b. 5 billion years
The rate of decay of radioactive materials is effected by geologic processes
True or False
False
What is the widely accepted age of the universe?
a. 20 billion years
b. 4.7 billion years
c. 13.7 billion years
d. 18.5 billion years
c. 13.7 billion years
The nebular hypothesis proposes that the solar system formed from a huge, swirling cloud of cosmic gas and dust
True or False
True
The planets formed when bits of solid matter from the solar nebula were drawn together by gravitational attraction and accretion
True or False
True
The sun is the center of our solar system
True or False
True
Where is the asteroid belt located?
a. between the orbits of mars and jupiter
b. between the orbits of earth and venus
c. outside of the solar system, in the oort cloud
d. between the orbits of saturn and uranus
e. in the belt of the constellation orion, the hunter
a. between the orbits of mars and jupiter
Which of the following moons has an atmosphere?
a. earth’s moon
b. callisto
c. titan
d. ganymede
e. triton
c. titan
Radiometric dating has allowed scientists to attach numerical ages to many of the events in the geologic timescale
True or False
True
