Astronomy Ch.8-10
Mercury's interior is unique because it ____.
has an unusually large fraction of iron core
What have tectonic forces done to venus surface
have broken the lava surface to create remarkable patterns of ridges and cracks, crust has also torn to form rift valleys.
What makes the planet's mountains, valleys, volcanoes, and even the continents and ocean basins themselves?
heat escaping from the interior
What does the thick atmosphere of Venus produce
high surface temperature and gives off a red light.
Describe Venus surface temperate
high surface temperature,
What are the there possibilities for the origin of earths atmosphere
(1) the atmosphere could have been formed with the rest of Earth as it accumulated from debris left over from the formation of the Sun; (2) it could have been released from the interior through volcanic activity, subsequent to the formation of Earth; or (3) it may have been derived from impacts by comets and asteroids from the outer parts of the solar system.
what are the 4 basic kinds of interaction between crust plates
(1) they can pull apart, (2) one plate can burrow under another, (3) they can slide alongside each other, or (4) they can jam together. Each of these activities is important in determining the geology of Earth.
ozone
(O3) a heavy molecule of oxygen that contains three atoms rather than the more normal two
mare
(plural: maria) Latin for "sea;" the name applied to the dark, relatively smooth features that cover 17% of the Moon's surface
Pressure of Mar's atmosphere
.0007 bar
What is the semi major axis of Mercurys orbit, aka average distance from the Sun?
.39 AU
what is the amount of the pressure exerted at sea level on earths surface from the atmosphere
1 bar- each square centimeter of earths surface has 1.03 kilograms pressing on it
What are the three general ideas for moons origin (there are problems with each)
1. The fission theory—the Moon was once part of Earth, but somehow separated from it early in their history. 2. The sister theory—the Moon formed together with (but independent of) Earth, as we believe many moons of the outer planets formed. 3. The capture theory—the Moon formed elsewhere in the solar system and was captured by Earth.(worst)
What were the three objectives of the Apollo mission
1. astronauts collected nearly 400 kilograms of samples for detailed laboratory analysis on Earth 2. each Apollo landing after the first one deployed an Apollo Lunar Surface Experiment Package (ALSEP)-worked for years after astronauts left 3. the orbiting Apollo command modules carried a wide range of instruments to photograph and analyze the lunar surface from above.
Why do we think there was once rivers flowing on mars
1. theres alot of small twisting channels (runoff channels) 2. outflow channels which are much larger with much water frozen in the soil as permafrost 3. gullies- smaller
how many tectonic plates is earth divided into?
12- they are either being pulled apart or pushed together
Mars rotates in ____________ hours and has _____________ like Earth; Venus has a ___________ rotation period of 243 days.
24, seasons, retrograde
rotational axis of mars
25 degrees- close to earth so it experiences seasons like earth
how far done is the core of the earth
2900 kilometers and is about 7000 kilometers in diameter
what is the pressure at the ocean floor
300 bars because 10 meters of water is equal to 1 bar
What is the surface age of venus
300 to 600 million years
The rate of cratering on the Moon is illustrated in your textbook. It is a correct conclusion form the figure that:
4 billion year old craters are more common than 3 billion year old craters
What is the total mass of earths atmosphere
5 x 10^ 18 kilograms
how much of earths crust do oceans cover
55%
What is mercury's period of rotation
59 days -2/3s of its revolution
describe the stratosphere
cold and free of clouds
Giant Impact Hypothesis
Earth was struck a long long time ago by an object 1/10 of earth size, like a bullet -largest impact earth could have experienced without shattering
Schiaparelli
Italian astronomer who said he could see channels on mars- English ppl thought he met "canals" implying artificial origin -started rumor of life on mars
When did the first american step on the moon
July 20, 1969
What is the smallest terrestrial planet?
Mercury
Many longer term climate variations, such as the ice ages, are related to changes in the planet's orbit and axial tilt.
Many longer term climate variations, such as the ice ages, are related to changes in the planet's orbit and axial tilt.
Which is the fastest moving planet and the closest to the sun
Mercury
How did Mercury lose so much of its silicate rocky material that scientists think it should have
Mercury is likely to have experienced several giant impacts very early in its youth, and one or more of these may have torn away a fraction of its mantle and crust, leaving a body dominated by its iron core.
how are we affecting CO2 levels
Modern industrial society depends on energy extracted from burning fossil fuels. As old coal and oil deposits are oxidized (burned using oxygen), large quantities of carbon dioxide are released into the atmosphere. we are also destroying sooo many tropical forests, which we depend on to extract CO2 from the atmosphere and replenish our supply of oxygen. In the past century of increased industrial and agricultural development, the amount of CO2 in the atmosphere increased by about 30% and continues to rise at more than 0.5% per year.
How does the diameter of mars compare to that of Earth
its half
When did abundant free oxygen start to become available in the atmosphere
Studies of the chemistry of ancient rocks show that it was 2 billion years ago
What happened in June 1908
Tunguska explosion- in siberia there was an explosion in the atmosphere about 8 kilometers above the surface that flattened more than a thousand square kilometers of forest. it killed soooo many animals and spread around the world. no craters were formed
Apollo Program
U.S. program that sent nine piloted spacecraft to our satellite between 1968 and 1972, landing 12 astronauts on its surface - 6 landed, 3 others circled the moon
Compare basic properties of Venus and Mars
VENUs- bigger mass, bigger diameter, larger gravity, rotation period of 243 days, larger surface area MARS- smaller, rotation period of 24.6 hours
how are most mountains formed
When two continental masses are moving on a collision course, they push against each other under great pressure. Earth buckles and folds, dragging some rock deep below the surface and raising other folds to heights of many kilometers.
photosynthesis
a complex sequence of chemical reactions through which some living things can use sunlight to manufacture products that store energy (such as carbohydrates), releasing oxygen as one by-product
talk about the core of earth
a dense metallic outer liquid layer but the innermost core is solid with high amounts of nickel and sulfur
bar
a force of 100,000 Newtons acting on a surface area of 1 square meter; the average pressure of Earth's atmosphere at sea level is 1.013 bars
greenhouse gas
a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range; on Earth, these atmospheric gases primarily include carbon dioxide, methane, and water vapor
What is the most popular and recent crater formed on earth
a lump of iron about 40 meters in diameter called Meteor Crater in Arizona- remains intact very rare
Cretaceous
a period of geological history. at the end of it a large object collided with earth 65 million years ago, it included a mass extinction- it hit a peninsular of mexico
volcano
a place where material from a planet's mantle erupts on its surface
Talk about volcanoes
associated with subduction zones and also where tectonic plates are colliding
Why do metamorphic rocks exist on earths surface
because geological activity carries surface rocks down to considerable depths and then brings them back up to the surface. Without such activity, these changed rocks would not exist at the surface.
Why are the moons highlands so heavily cratered
because they formed so early in human history
What is the most prominent visible surface feature on mars through a telescope
bright polar caps that change with seasons
Venus appearance
bright, goes thro phases like moon, cant see actual surface bc of dense clouds that reflect suns light
How do seismic waves tell us about a planet
by monitoring the waves through a planet, we learn about the layers its traveled through. whether the waves refract (bend) or if vibrations travel along the surface
why do we have such specific measurements of mars
by watching the motion of permanent surface markings over a long long time, 200 years
What is martian are composed of
carbon dioxide (95%), nitrogen and argon
What is the most abundant gas on Venus? second?
carbon dioxide -96% of atmosphere, and nitrogen
Name three things that plate tectonics take part in
carbon dioxide cycle, existence of earthquakes, creation of mountain ranges
core
central part of a planet that consists of higher density material
How is this increase in CO2 affecting the environment
complex changes in climate, and may be catastrophic for many species
geological activity on Mars
cratered highland terrain and volcanic plains
Moon Dust
dark basaltic fine grained soil of dust that covers the surface of the moon from impacts
what have living things done to the levels of carbon dioxide in earths atmosphere
decrease in atmospheric carbon dioxide
Describe ancient lakes on mars
dried out lake beds back when mars was warmer and atmosphere thicker- some covered by thin lava flow
What is the moon made of
entirely silicone rock- depleted of iron and other materials compared to earth
The high temperature of Venus is caused by
excess of carbon dioxide in the atmosphere
theory of plate tectonics
explains how slow motions within the mantle of earth move large segments of the crust and causes the shifting of the continents on earth
What are maria again
flat plains of balsamic lava that came from volcanic eruptions billions of years ago
Tectonic
forces that push and stretch the crust- like in Venus
What did the presence of oxygen allow
formation of the ozone layer, which allowed for colonization of the land and evolvement of animals.
Tectonic
geological features that result from stresses and pressures in the crust of a planet; tectonic forces can lead to earthquakes and motion of the crust
How did we study geology of Venus
global study of its surface, its hard because of the cloud layers around the planet, so use a radar instrument to probe through layer -mapped Venus with imaging radar - RADAr MAPS
In the absence of any air, the lunar surface experiences much _____________ temperature extremes than the surface of Earth
greater- it also goes extremely extremely cold at night
Why is venus so hot when it is just as close to the sun as earth is?
greenhouse effect- the thick thick layer of Co2 taps infrared heat below the atmosphere and it heats it up sooo much.
All volcanically produced rock is ________________________
igneous
basalt
igneous rock produced by the cooling of lava and makes up the most of earths oceanic crust and is found on other planets that have experience volcanic activity
Fault
in geology, a crack or break in the crust of a planet along which slippage or movement can take place, accompanied by seismic activity
rift zone
in geology, a place where the crust is being torn apart by internal forces generally associated with the injection of new material from the mantle and with the slow separation of tectonic plates
what is leading to global warming
increasing amounts of atmospheric CO2
Describe surface of venus
inhospitable, pressure at 90 bars and temperature of 730 K
What heavy elements is earth primarily composed of
iron, silicon and oxygen (rather than hydrogen and helium)
why do we need carbon dioxide
it helps retain heat from the sun through the greenhouse effect
how does the ozone help life on earth
it is a good absorber of ultraviolet light, it protects the surface from some of the Sun's dangerous ultraviolet radiation
mantle
largest part of earths interior between the crust and the core
The maria are much _____ cratered than the highlands, and cover just ______ of the lunar surface, mostly on the side of the Moon that faces Earth
less, 17%
Mercurys Surface
like the moon, covered with thousands of craters and larger basins
Scarps
long curved cliffs on Mercury that came from the slight compression of mercurys crust- most likely from the planets shrinkage over time, NO evidence of plate tectonics
What is on 75% of Venus surface
lowland lava plains
The Earth has a two parts to its core which allow it to move within the Earth. This creates Earth's
magnetic field
How is earths interior measured
measuring the transmission of seismic waves through earth
Difference between Mercury and Moon
mercury has a heavily cratered surface and no atmosphere like the moon, but it differs in having a very large metal core
Where do the charged particles trapped in our magnetosphere come from?
outward from the hot surface of the sun (solar wind)
Describe Mercurys Composition
mercury has a high density, so it must have heavy materials- like metals -iron nickel core thats 60% of its total mass with the rest of the planet made of silicates- it has a weak magnetic field and a large metal core that is partly liquid in order to generate that magnetic field
All of the following are greenhouse gases except for:
molecular nitrogen
Moon's atmosphere
moon is too small, too light, not enough mass to retain an atmosphere. atmosphere is lost by freezing onto the surface or escaping to surrounding space
The _________ CO2 there is in our atmosphere, the __________ the temperature at which Earth's surface reaches a new balance.
more, higher
Olympus Mons
most dramatic volcano on mars- probs the largest in our solar system
Convection
movement caused within a gas or liquid by the tendency of hotter, and therefore less dense material, to rise and colder, denser material to sink under the influence of gravity, which consequently results in transfer of heat
Where did the features of Venus's surface come from
movements of venus crust, volcanic eruptions, and impact craters
Does mars have a magnetic field
no
Is there any primitive rock left on earth
no because the entire planet was heated in its history.
Geological Activity of Venus
no water, no ice, low wind so nothing changed by erosion, basically its earth without erosion, has lowland lava plains, mountainous terrain as a large as continents
Future moon plans
none for Russia or Us. China is planning to soon. spacecraft from NASA,ESA, japan,India, and china orbit the moon
Is the age of a planetary surface the same as the age of the world it is on?
nope- rarely are they the same age b/c a young surface area age only implies active geological activity
Does the thick atmosphere of venus protect it from impacts
not all projectiles only small ones does the atmosphere burn up
What are the seasons caps on mars composed of?
not ordinary snow but frozen CO2
What is earths crust largely made of?
oceanic basalt and continental granite -which are both igneous rock
crust
outer layer of a terrestrial planet
Why doesnt earth see as many craters as the moon
over history the earth has been affected as badly as the moon, yet overtime these craters have been destroyed by earths geological activity- plate tectonics have erased impact craters
Why are plate tectonics a cooling system for the planet
plate tectonics is a mechanism for Earth to transport heat efficiently from the interior, where it has accumulated, out to space.
What causes earthquakes
plates rubbing against each other and building stress in the crusts
Mars appearance
red color from iron oxide in its soil, no hint of mountains, valleys, impact craters but it does have bright polar ice caps
sedimentary rock
rock formed by the deposition and cementing of fine grains of material, such as pieces of igneous rock or the shells of living things
Igneous Rock
rock produced by cooling from a molten state
Metamorphic Rock
rock produced by physical and chemical alteration (without melting) under high temperature and pressure
primitive rock
rock that has not experienced great heat or pressure and therefore remains representative of the original condensed materials from the solar nebula
How old is moon
rocks on moon, 3.3-4.4 billion years older, older than earth. but both earth and moon are between 4.5- 4.6 years old
What are examples of sedimentary rock
sanstones, shales, limestones
What are basalts made of
silicon, oxygen, iron, aluminum, and magnesium
Current day Earth and Venus are similar in
size
Describe water on mars
small amounts of water vapor and occasional clouds of water ice, but no liquid water, mainly because of the low temperatures
Water on moon
small evidence has been found of a small amount of water near the lunar poles, most likely from comet and asteroid impacts
Geology
study go earths crust and how is it shaped
Where are most rift zones
the ocean
describe the composition of the atmosphere at earths surface
the atmosphere consists of 78% nitrogen (N2), 21% oxygen (O2), and 1% argon (Ar), with traces of water vapor (H2O), carbon dioxide (CO2), and other gases. Variable amounts of dust particles and water droplets are also found suspended in the air.
greenhouse effect
the blanketing (absorption) of infrared radiation near the surface of a planet—for example, by CO2 in its atmosphere
where do clouds form and airplanes fly
the bottom 10 kilometers of earths atmosphere called the troposphere
Chicxulub
the crater that ended the dinosaurs- 5 billion nuclear bombs and lifted 100 trillion tons of dust into the atmosphere
Plate tectonics plays a role in all of the following except:
the earths magnetic field
Mars has less water due to the Solar wind and the lack of magnetic field protection. It destruction has caused all below except for ___.
the higher volcanos on Mars
How did earths early atmosphere affect life
the lack of oxygen allowed for many complex chemical reactions to form amino acids, proteins, and other chemical building blocks of life that all could have combined to make organisms
stratosphere
the layer of Earth's atmosphere above the troposphere and below the ionosphere
highlands
the lighter, heavily cratered regions of the Moon, which are generally several kilometers higher than the maria (83% 0f surface) -have low ,rounded profiles because there is no wind or water on earth to erode them because there is no atmosphere or water on the moon
troposphere
the lowest level of Earth's atmosphere, where most weather takes place
plate tectonics
the motion of segments or plates of the outer layer of a planet over the underlying mantle
What does primitive rock tell us
the original material out of which the planetary system was made
runaway greenhouse effect
the process by which the greenhouse effect, rather than remaining stable or being lessened through intervention, continues to grow at an increasing rate
magnetosphere
the region around a planet in which its intrinsic magnetic field dominates the interplanetary field carried by the solar wind, hence, the region within charged particles can be trapped by the planetary magnetic field
subduction
the sideways and downward movement of the edge of a plate of Earth's crust into the mantle beneath another plate
mass extinction
the sudden disappearance in the fossil record of a large number of species of life, to be replaced by fossils of new species in subsequent layers; mass extinctions are indicators of catastrophic changes in the environment, such as might be produced by a large impact on Earth
Why was the development of blue-green algae important
they take in carbon dioxide from the environment and release oxygen as waste- they gave rise to plants
Is the martian atmosphere thin or thick
thin
list layers of the atmosphere from closest to surface to tallest
troposphere, stratosphere, ozone, mesosphere, ionosphere
granite
type of igneous silicate rock that makes up the most of earths continental crust
which planet is earths twin
venus
Temp on Mercury
very hot on its daylight side and super super cold during nights because it has no atmosphere
a seismic wave
vibration that travels through the interior of earth or any other objection, on earth they are usually caused by earthquakes
Martian Meteorites
volcanic basalts that could have been blasted from Mars by fragments and came to earth so we could study them- they have both water and carbon based compounds in them
What is going on with air at the troposphere
warm air, heated by the surface, rises and is replaced by descending currents of cooler air (convection)
Seismic Waves
waves that spread through the interior of earth from earthquakes or explosion sites
How did we measure the age of moon
we must estimate the ages of individual rocks using radioactive dating techniques
Does venus experience volcanism
yes- large flows of lava are always generating new surface
How can Venus rotation period be found
you cant see any of venus surface material, so we must bounce radar signals off the planet
The lunar maria are _____ than the lunar highlands and appear _____ than those highlands.
younger, darker
