exam 4 astronomy review
Why is Earth's continental crust lower in density than seafloor crust?
Continental crust is made as the lowest-density seafloor crust melts and erupts to the surface near subduction zones.
From center to surface, which of the following correctly lists the interior of layers of a terrestrial world?
Core, mantle, and crust.
conditions necessary for terrestrial planet to have a strong magnetic field?
both a molten and metallic core & reasonably fast rotation
how have we been able to construct detailed maps of surface features on venus?
by using radar from spacecraft that were sent to orbit venus.
The processes responsible for virtually all surface geology are ____.
impact cratering, volcanisms, tectonics, and erosion
describes our understanding to flowing water on mars?
importance once, but no longer
determines the thickness and strength of the lithosphere?
internal heat
Based on all we know about the terrestrial worlds, what single factor appears to play the most important role in a terrestrial planet's geological destiny?
its size
Which of the following is the underlying reason why Venus has so little wind erosion?
its slow rotation
another photograph 10 minutes later?
looked virtually the same
Which two factors are most important to the existence of plate tectonics on Earth?
mantle convention and a thin lithosphere
newly detected extrasolar planets called "Hot Jupiters"?
masses are similar to Jupiter but they are very close to the central star, therefor they are hot
rank planets based on their cooling rates, fastest to slowest.
mercury mars venus earth
The cores of the terrestrial worlds are made mostly of metal because
metals sunk to the centers a long time ago when the interiors were molten throughout.
4 galilean moons around jupiter are made of...
mixture of rock and ice
key message that can be read from this graph?
model supports the conclusion that human emissions are driving global warming
transit method?
monitor brightness of a star as the planet passes infront of the stars disk, stars light dims slightly because the planet blocks some of the stars visible light, technique works only in rare cases when the planets orbit is nearly edge-on.
5 terrestrial worlds. smallest to largest
moon mercury mars venus earth
features that could only exist with a magnetic field?
northern lights
significance of circular region?
outlines the crater from the impact thought to have killed off dinosaurs.
What are the two geological features that appear to set Earth apart from all the other terrestrial worlds?
plate tectonics and widespread erosion
which internal energy source is the most important in continuing to heath the terrestrial planets today?
radioactivity
Which of the following best describes the lunar maria?
relatively smooth, flat plains on the moon.
significance of the yellow lines on this map?
represents the boundaries between the plates that make up earths lithosphere
How does seafloor crust differ from continental crust?
seafloor crust if thinner, younger, and higher in density.
planet's fundamental properties has the greatest effect on its level of volcanic and tectonic activity?
size
Which of the following is not generally true of all the terrestrial lithospheres?
the lithosphere is broken into a set of large plates that float on the softer rock below
Which of the following does not provide evidence that Mars once had abundant liquid water on its surface?
the presence of canali, discovered, in the late 1800s by Giovanni Schiaparelli and mapped by Percival Lowell
What observational evidence supports the idea that Mercury once shrank by some 20 kilometers in radius?
the presence of many long, tall cliffs.
In the context of planetary geology, what do we mean by outgassing?
the release by volcanism of gases that had been trapped in a planetary interior.
how many other planetary systems have been discovered to date?
thousands
most responsible for generating the internal heat of lo that drives the volcanic activity?
tidal heating
moon has most substantial atmosphere?
titan
without green house gases, earths surface would be frozen over?
true
kepler mission?
uses the transit method to search for the earth-size planets in earth-like orbits
You can discover an impact crater that is 10 kilometers across. Which of the following can you conclude?
It was created by the impact of an object about 1 kilometer across.
Which of the following most likely explains why Venus does not have a global magnetic field like Earth?
Its rotation is too slow.
What's the fundamental reason that Mars has so little geological activity?
Its small size compared to Earth
Why does the moon have a layer of "powdery soil" on its surface?
It is the result of countless tiny impacts by small particles striking the moon.
first planets around other sun-like stars were discovered?
1990's
what terrestrial world is shown in this visible light photo?
Venus
world with largest substantial atmosphere?
Venus
Which one offers evidence of a global repaving about a billion years ago?
Venus has relatively few impact craters and there craters are distributed fairly evenly over the entire planet.
The major processes that hear the interiors of the terrestrial worlds are ____.
(1) Heat deposited as the planets were built from planetesimals; (2) heat deposited as the planets underwent differentiation; and (3) heat released by radioactive decay.
planet associated with the wobble has an orbital period of...?
6 months
What are the basic requirements for a terrestrial world to have a global magnetic field?
A core layer of molten, convecting material and sufficiently rapid rotation.
In general, which things below are affected by a magnetic field?
Charged particle of magnetized materials (such as iron)
Which of the following best describes the geological histories of the Moon and Mercury?
Early in their histories, they suffered many impacts and experienced some volcanism and tectonics, but they now have little geological activity at all.
Which of the following places is the result of volcanoes erupting over a hot spot in the mantle?
Hawaii
Recent evidence suggests that mars once had a global magnetic field. Assuming this is true, which of the following could explain why Mars today lacks a global magnetic fields like that of Earth?
Mars's interior has cooled so much that its molten core layer no longer undergoes convection.
planet we see occasionally transit across the face of the sun?
Mercury
The choices describe four hypothetical planets. Which one would you expect to have the hottest interior?
Size: twice as big as Earth. Distance from the sun: same as mercury. Rotation Rate: once every 6 months
Suppose we had a device that allowed us to see Earth's interior. If we looked at a typical region of the mantle, what would we see happening?
On human time scales, the mantle looks the solid rock, so not much would be seen.
Why are there fewer large impact craters on the Earth's seafloor than on the continents?
Seafloor crust is younger than continental crust, so it has had less time in which to suffer impacts.
The choices describe hypothetical planets? Which one you expect to have the most features of erosion?
Size: same as Venus. Distance from the sun: same as Mars. Rotation rate: once every 25 hours.
The choices describe four hypothetical planets. Which one would you expect to be most crowded with impact craters?
Size: same as the moon. Distance from the sun: same as Mars. Rotation Rate: once every 10 days.
Which of the following is not an example of tectonics?
The gradual disappearance of a crater rim as a result of wind and rain.
Many scientists suspect that Venus has a stronger and thicker lithosphere that Earth. If this is true, which of the following could explain it?
The high surface temperature that has "baked out" all the liquid water from Venus's crust and mantle.
Most of the Moon's surface is densely covered with craters, but we find relatively few craters within lunar maria. What can we conclude?
The maria formed after a heavy bombardment ended.
Which of the following is an example of convection?
Warm air expanding and rising, whereas cooler air contracts and fall.
What do we mean when we say that the terrestrial worlds underwent differentiation?
When their interiors were molten, denser materials sank toward their centers and lighter materials rose toward their surfaces.
pluto most resemble?
a comet
On average, how fast do the plates move on earth?
a few centimeters per year
Based on its surface features, the most important event on Venus in the past billion years or so was ____.
a global "repaving" that erased essentially all the surface features that had existed earlier.
Suppose we use a baseball to represent Earth. On this scale, the other terrestrial worlds (Mercury, Venus, the Moon, and Mars) would range in size approximately from that of ____.
a golf ball to a baseball
Olympus Mons is ____.
a huge shield volcano on Mars
The reason that small planets tend to lose interior heat faster than larger planets is essentially the same as the reason that ___.
a large baked potato takes longer to cool than a small baked potato.
A terrestrial world's lithosphere is ____.
a layer of relatively strong, rigid rock, encompassing the crust and part of the mantle.
In the context of plate tectonics, what is a subduction zone?
a place where a seafloor plate is sliding under a continental plate.
asteroids and comets differ in composition?
asteroids form inside the frost lines, comets formed outside
Halley comet named after Edumund haley because
calculated its orbit and predicted that it would return in 1758.
figure tells us?
current level of carbon dioxide in our atmosphere is higher than it has been ever
core, mantle, and crust of a planet are defined by differences...
density
amount of time the surface of the planet that has had a moderate to high level of volcanic/tectonic activity, longest-shortest
earth mars mercury
worlds with the thinnest lithospheres?
earth and venus
how fast do plates move on earth?
few centimeters per year