Astronomy Test 3
Which planets have moons
Mercury - 0 known moons Venus - 0 known moons Earth - 1 known moon (the Moon) Mars - 2 known moons (Phobos and Deimos) Jupiter - 79 known moons (including the four largest, Io, Europa, Ganymede, and Callisto) Saturn - 82 known moons (including the largest, Titan) Uranus - 27 known moons (including the largest, Titania) Neptune - 14 known moons (including the largest, Triton)
True or False: The destruction of the ozone layer is responsible for most of our issues with global climate change.
False
What is the sun's surface temperature?
$5778 K
True or False: The main source of solar energy is chemical reactions (e.g., oxidation) in the core of the Sun.
False
Discuss several ways that CMEs can adversely affect Earth.
Geomagnetic storms, radiation hazards, satellite hazards, auroras, aviation hazards.
Planets largest to smallest (Gas giants)
Jupiter Saturn Uranus Neptune
What are the planets from hottest to coldest? (Gas Giant)
Jupiter - despite being a gas giant planet with no solid surface, Jupiter's outer atmosphere has an average temperature of -145°C (-234°F). Saturn - like Jupiter, Saturn has no solid surface and its outer atmosphere has an average temperature of -178°C (-288°F). Uranus - with an average temperature of -216°C (-357°F), Uranus is the coldest of the planets in our solar system. Neptune - with an average temperature of -218°C (-360°F), Neptune is only slightly colder than Uranus.
Scarps seen on the surface of Mercury are evidence of what?
of shrinking of the planet long after its initial formation.
Ozone Layer and CFCs:
A form of oxygen with three atoms per molecule. Protects the surface from UV radiation. Typically slightly warmer. The breakup of the ozone leads to heat in the stratosphere. CFCs, or chemicals that cause ozone depletion were phased out in the 1980s to protect that region. The ozone layer is slowly regenerating.
From what areas of the Sun does the solar wind predominantly originate?
coronal zones
How did the solar system form?
1.) Cloud collapse: The initial collapse of the solar nebula was triggered by some kind of external disturbance, such as a nearby supernova or shockwave. This caused the cloud to begin contracting and rotating. 2.) Formation of a protostar: As the cloud collapsed, it began to heat up due to the release of gravitational potential energy. At the center of the collapsing cloud, a dense core formed, which eventually became hot enough and dense enough to initiate nuclear fusion and become a protostar. 3.) Formation of a disk: As the protostar formed, it ejected material from its equator, which formed a disk of gas and dust around it. This disk is known as a protoplanetary disk and is thought to be the birthplace of planets. 4.) Accretion of planetesimals: Within the protoplanetary disk, small particles of dust and ice began to stick together, forming larger and larger objects known as planetesimals. 5.) These planetesimals collided and merged to form larger bodies, eventually leading to the formation of planets. 5.) Clearing of the disk: As the planets formed and began to grow, they cleared out their orbits in the protoplanetary disk, accreting or ejecting any remaining planetesimals or dust.
What are the moon formation theories?
1.) Co-accretion 2.) Capture 3.) Fission 3.) Giant impact - most probable
What are the Layers of the Sun
1.) Core: The innermost layer of the Sun, where nuclear fusion reactions take place and produce the energy that powers the Sun. 2.) Radiative zone: The region surrounding the core where energy is transported outward by radiation. 3.) Convective zone: The region above the radiative zone where energy is transported by convection, as hot gas rises and cooler gas sinks.
While we do not expect life to exist on any of the giant planets, several of their moons have conditions that might support life. List several of these moons (and their associated planet) and briefly explain what makes each a possible location for life to form.
1.) Titan (Saturn): Titan's atmosphere is composed primarily of nitrogen, with trace amounts of methane and other gases and has lakes and seas of liquid methane and ethane on its surface, which could provide a potential habitat for life forms that use different types of chemistry than we are familiar with on Earth. 2.) Europa (Jupiter): Europa is a promising location for life due to the presence of a subsurface ocean of liquid water that is in contact with the moon's rocky mantle, creating a potentially habitable environment. There is also evidence of geothermal activity on Europa, which could provide the energy necessary to support life. 3.) Ganymede (Jupiter): Ganymede is the only moon known to have its own magnetic field. This field could help to protect any potential life on the moon from harmful radiation from Jupiter. Ganymede is also thought to have a subsurface ocean of saltwater, which could potentially support life.
What are the layers of the Sun's atmosphere?
4.) Photosphere: The visible surface of the Sun where most of the Sun's light and heat is emitted. 5.) Chromosphere: The region above the photosphere, where the temperature increases with altitude and a variety of features such as spicules and prominences can be observed. 6.) Transition region: The narrow region between the chromosphere and the corona where the temperature increases rapidly from thousands to millions of degrees. 7.) Corona: The outermost layer of the Sun's atmosphere, which extends for millions of kilometers and is visible during a total solar eclipse. The corona is much hotter than the underlying layers, with temperatures reaching several million degrees Celsius.
What is a Protosun?
A protosun, also known as a protostar, is a large cloud of gas and dust that is collapsing under its own gravity to become a star. In the early stages of its formation, a protosun is not yet a true star, as it has not yet initiated the fusion of hydrogen into helium in its core. However, as the protosun continues to collapse, it becomes hotter and denser, eventually reaching a temperature and density sufficient to ignite nuclear fusion and become a true star.
What is a solar nebula? How did it collapse?
A solar nebula is a large cloud of gas and dust that collapses under its own gravity to form a star and its surrounding planetary system. The solar nebula that created our solar system is believed to have formed about 4.6 billion years ago from a giant molecular cloud that contained the raw materials for our Sun and its planets. The initial collapse of the solar nebula was triggered by some kind of external disturbance, such as a nearby supernova or shockwave. This caused the cloud to begin contracting and rotating.
Which has more mass, four 1H nuclei or one 4He nucleus?
A. The one 4He nucleus
The condition where the pressure of a liquid or gas is able to balance the weight of the layers above it leading to stability is called
A. hydrostatic equilibrium
Lunar Regolith
AKA Moon dust Lunar regolith is the layer of loose, fragmented material that covers the surface of the Moon. It is made up of a mixture of dust, rock fragments, and other materials, and is the result of billions of years of meteoroid impacts on the Moon's surface. The regolith can vary in depth from just a few centimeters to over 20 meters deep in some places.
What is accretion? How does it relate to the formation of the solar system?
Accretion is a process by which particles or objects come together and stick to form a larger object. In the context of the formation of the solar system, accretion refers to the process by which solid particles in the protoplanetary disk collided and stuck together, forming progressively larger objects. As the protoplanetary disk cooled, solid particles began to condense out of the gas and dust. These particles, ranging in size from tiny dust grains to larger pebbles and boulders, collided with each other and stuck together through a process called accretion. The larger the particles became, the stronger their gravity became, allowing them to attract more particles and grow even larger. Over time, the accretion process led to the formation of planetesimals, which were larger objects ranging in size from a few meters to several kilometers. These planetesimals were the building blocks of the planets, moons, and asteroids in the solar system. They continued to accrete more and more material until they grew into protoplanets, which eventually became the planets we know today.
Plate tectonics
An idea that explains how slow motions within the mantle of earth move large segments of the crust, resulting in gradual drifting of the continents as well as the formation of mountains and other large-scale geological features. Powered by convention in the mantle - a process by which heat escapes from the interior through the upward flow of warmer material and the slow sinking of cooler material.
The "canals" that Percival Lowell mapped for the surface of Mars in the early 1900's have are now generally accepted to be
An optical illusion
How hot must the core of a star be to initiate the proton-proton chain? A. 5800 K B. around 100,000 K C. around 12 ×106 K D. around 1042 K
C. around 12 ×106 K
Describe the composition of the moon
Composition: The Moon is primarily composed of rock and metal, with a surface layer of fine dust and debris called regolith. The Moon's crust is largely made up of a rock called anorthosite, which is high in aluminum content. The Moon also contains minerals such as iron, silicon, magnesium, calcium, and titanium. The Moon does not have a significant atmosphere or water on its surface.
What is condensation? How does it relate to the formation of the solar system?
Condensation is a process by which a substance changes from a gaseous state to a liquid or solid state. It occurs when the temperature of a gas is lowered below its dew point or saturation point, causing its molecules to come together and form droplets or crystals. In the context of the formation of the solar system, condensation refers to the process by which solid particles formed in the protoplanetary disk around the young Sun. As the disk cooled, volatile substances, such as water, methane, and ammonia, began to condense and form solid particles. These particles grew larger by sticking together through a process called accretion. Over time, these solid particles grew into planetesimals, which eventually formed the planets, moons, and asteroids in the solar system.
The transfer of energy via collisions between atoms or molecules is called
Conduction
How do we determine the diameter of the sun?
Diameter: The diameter of the Sun can be measured using various techniques, such as lunar occultations, solar eclipses, and interferometry. During a lunar occultation, the Moon passes in front of the Sun, blocking its light. By measuring the timing and duration of the occultation from different locations on Earth, astronomers can calculate the diameter of the Sun. Similarly, during a solar eclipse, the Moon partially or fully blocks the Sun's disk, allowing astronomers to measure its diameter. Interferometry involves combining the light from multiple telescopes to create an interferogram, which can be used to determine the size of the Sun's disk.
Differentiation of Terrestrial Planets
Differentiation is the process by which the interior of a planetary body becomes separated into distinct layers based on differences in density and composition. The terrestrial planets in our solar system - Mercury, Venus, Earth, and Mars - all underwent differentiation early in their history. During the early stages of planetary formation, the terrestrial planets were composed of a mix of rock and metal. As the planets grew in size, their interiors heated up due to the heat generated by the decay of radioactive isotopes and gravitational energy from the accretion of material. The heat caused the materials inside the planet to partially melt and become partially molten or "magma." The denser metallic elements, such as iron and nickel, sank to the core, while the lighter rock and mineral material floated to the top and formed the crust and mantle.
How do we determine the distance from the sun?
Distance: The distance to the Sun can be determined using a variety of techniques, such as radar ranging, parallax measurements, and triangulation. The most precise method is radar ranging, which involves bouncing a radar signal off the surface of Venus and measuring the time it takes for the signal to return to Earth. By knowing the distance to Venus and the angle between the Sun, Venus, and Earth, astronomers can calculate the distance to the Sun.
What is the meaning of E = mc^2
E = mc^2 is one of the most famous and important equations in physics, and it represents the relationship between mass and energy. The equation was first proposed by Albert Einstein in 1905 as part of his theory of special relativity. The equation states that energy (E) is equal to mass (m) multiplied by the square of the speed of light (c^2). In other words, mass and energy are interchangeable and can be converted from one form to another, as long as the speed of light is taken into account. This means that even a small amount of mass can be converted into a large amount of energy, as the speed of light is a very large number (approximately 299,792,458 meters per second). For example, the energy released by the explosion of an atomic bomb is the result of the conversion of a small amount of mass into a tremendous amount of energy, as described by the equation E = mc^2.
Planets largest to smallest (terrestrial)
Earth Venus Mars Mercury
How do we determine elemental abundances for the sun?
Elemental Abundances: The elemental abundances of the Sun can be determined using spectroscopy, which involves analyzing the spectrum of its light. By breaking down the Sun's radiation into its constituent wavelengths, astronomers can identify the spectral lines produced by various elements and measure their relative strengths. This information can be used to determine the abundances of different elements in the Sun's atmosphere.
The Sun's Gravitational Energy
Gravitational energy is a form of potential energy that depends on the position of an object relative to a massive body, such as the Sun. The greater the distance between two objects, the greater the potential energy between them. This means that objects in orbit around the Sun have gravitational potential energy that is directly proportional to their distance from the Sun. The Sun's gravitational energy is also related to its internal structure. The Sun is divided into layers, with the core being the densest and hottest part of the Sun. As a result of its mass, the gravitational energy at the core of the Sun is extremely high, and it is this energy that powers the nuclear fusion reactions that generate the Sun's heat and light.
What is the explanation for why sunspots look cooler and darker than the rest of the Sun?
Sunspots are places where the strong magnetic fields in the Sun resist the upward motion of bubbling hot gases from underneath
Which solar system moon has active volcanoes on its surface due to tidal flexing?
Io
What are the Galilean moons and what is something interesting about each of them?
Io: Io is the closest of the Galilean moons to Jupiter and is the most volcanically active object in our solar system. Its surface is constantly changing due to the eruptions of sulfur and other materials from its numerous active volcanoes. Io's volcanic activity is powered by tidal heating from Jupiter's strong gravity. Europa: Europa is an icy moon with a surface that is covered by a layer of ice. Underneath the ice, there is believed to be a subsurface ocean of liquid water, which makes Europa one of the most likely places in our solar system to harbor life. Europa's ocean is thought to be in contact with a rocky seafloor, providing the necessary chemical ingredients and energy for life to exist. Ganymede: Ganymede is the largest moon in our solar system and is even larger than the planet Mercury. It has a rocky core, surrounded by a thick layer of ice, and a thin atmosphere of oxygen. Ganymede is also the only moon in our solar system known to have its own magnetic field. Callisto: Callisto is the outermost of the Galilean moons and has a heavily cratered surface, indicating that it has remained relatively unchanged since its formation. It is believed to have a subsurface ocean of liquid water, similar to Europa, but it is not as deep and is covered by a layer of ice that is much thicker. Callisto also has a weak magnetic field, generated by the interaction of its atmosphere with Jupiter's magnetic field.
Why are filters that only transmit light at the wavelength of a spectral line associated with ionized calcium useful for viewing the chromosphere, reducing the overpowering light of the photosphere?
Ionized calcium spectral lines only occur at the higher temperatures of the chromosphere and not at the temperatures found in the photosphere.
How do we determine the luminosity of the sun?
Luminosity: The luminosity of the Sun can be determined using its distance and brightness. By knowing the distance to the Sun and measuring its apparent brightness, astronomers can calculate its luminosity using the inverse square law.
When Galileo first turned his telescope to the Moon, he saw that the darker areas of the Moon looked smooth and mistakenly thought they were water, calling them maria, which is Latin for seas. What do we now understand maria to be, and what are they composed of?
Maria on the moon are vast basins that were filled with molten lava early in the moon's history that filled impact basins from other space debris. These regions are comprised of basalt and are most prevalent on the near side of the moon.
What is the evidence from neutrinos of solar energy production?
Neutrinos are subatomic particles that are produced in nuclear reactions, including the fusion reactions that power the sun. Because neutrinos have very little mass and interact very weakly with matter, they can travel straight through the sun and the Earth, essentially unaffected by other particles. By detecting the neutrinos that are produced in the sun's core and studying their properties, scientists have been able to gather important evidence about the process of solar energy production. In particular, the study of solar neutrinos has helped to confirm the theory of solar fusion and has provided valuable insights into the internal workings of the sun. Several experiments have been conducted to detect solar neutrinos, including the Homestake experiment in South Dakota and the Super-Kamiokande experiment in Japan. These experiments have shown that the number of neutrinos detected on Earth is lower than predicted by models of solar fusion, a phenomenon known as the "solar neutrino problem".
How do we determine the surface temperature of the sun?
Surface Temperature: The surface temperature of the Sun can be estimated using the laws of blackbody radiation and the measurement of its spectral energy distribution. By analyzing the spectrum of the Sun's radiation, astronomers can determine the wavelength at which it emits the most energy and use this to calculate its temperature.
Nuclear fission
Nuclear fission is a process by which the nucleus of an atom is split into two or more smaller nuclei, releasing a large amount of energy in the process. This process is the basis for nuclear power plants and nuclear weapons. In nuclear fission, an atomic nucleus is bombarded with neutrons, causing it to split into two or more smaller nuclei and releasing additional neutrons, as well as a large amount of energy in the form of radiation and thermal energy. The released neutrons can then go on to cause further fission reactions, creating a self-sustaining chain reaction. One of the most common fission reactions involves the splitting of uranium-235 (U-235) nuclei. When U-235 is bombarded with neutrons, it can split into two smaller nuclei, as well as several additional neutrons. These released neutrons can go on to cause further fission reactions, releasing additional energy and more neutrons.
What problem has finding "hot Jupiters" around other stars caused for the solar nebula theory, and how might this be explained?
One problem is that they orbit too close to their stars. Gas giants need cold temperatures to form.
How do planetesimals form?
Planetesimals form through a process called accretion, which involves the collision and sticking together of solid particles in the protoplanetary disk surrounding a young star. The protoplanetary disk is made up of gas and dust, and as the disk cools, the dust particles begin to condense and form solid particles. These particles range in size from tiny dust grains to larger pebbles and boulders. As these particles orbit the young star, they collide and stick together through the process of accretion. As more and more particles accumulate, the object's gravitational attraction grows stronger, allowing it to attract even more particles and grow in size. Over time, these growing objects become planetesimals, which are intermediate in size between the small solid particles and the larger planets. Planetesimals range in size from a few meters to several kilometers and can continue to grow through collisions with other planetesimals and the accretion of more solid particles.
What causes the magnetic field?
The magnetic field is generated by moving material in Earth's liquid metallic core. As the liquid metal inside the earth circulates, it sets up a circulating electric current. When many partials are moving together like that they produce a magnetic field.
How do protoplanets form?
Protoplanets form from the accumulation and gravitational attraction of planetesimals, which are intermediate-sized objects that have formed through the process of accretion in the protoplanetary disk surrounding a young star. As the planetesimals grow in size, their gravitational attraction becomes stronger, allowing them to attract even more particles and planetesimals. Over time, these growing objects become protoplanets, which are larger than planetesimals but smaller than fully formed planets. Protoplanets continue to accrete more material, growing larger and more massive. As they grow, their gravitational attraction becomes stronger, allowing them to attract even more material, including gas and dust from the surrounding protoplanetary disk. This process is known as gas accretion. As a protoplanet grows and its mass increases, its gravity becomes stronger, and it can begin to clear its orbit of smaller objects. Once a protoplanet has cleared its orbit, it becomes a fully formed planet.
What is the difference between rift and subduction zones?
Rift Zone: The place where plates pull apart, driven by upward currents in the mantle. Mostly in oceans. Molten rock rises from below to fill the space between the receding plates. Subduction Zones: The place where plates come together with one plate being forced beneath another. Often marked by a trench
A type of planet that surveys of exoplanets are revealing around other stars, but for which we don't have any examples around the Sun are:
super Earths
What are Solar Flares
Solar flares are sudden, intense bursts of radiation that originate from the Sun's surface and extend outward into its atmosphere. They are some of the most energetic events in the solar system and can release as much energy as millions of nuclear bombs. Solar flares are caused by the rapid release of energy stored in the Sun's magnetic field, which is constantly changing and interacting with the surrounding plasma. As the magnetic field lines twist and contort, they can become unstable and release energy in the form of light, X-rays, and high-energy particles. Solar flares can have a range of effects on Earth, including interference with satellite and communication systems, disruptions to power grids, and increased radiation exposure for astronauts and airline passengers. They can also create spectacular displays of auroras, or Northern and Southern Lights, at high latitudes.
Which planets have atmospheres? What does this tell us?
Tells us that they are surrounded by a layer of gases that are held in place by gravity.
Does the moon have an atnosphere?
The Moon has a very tenuous atmosphere, sometimes called an exosphere, but it is not a true atmosphere like Earth's. The Moon's atmosphere is mainly composed of a few elements, including helium, neon, and argon, that are released from the lunar surface due to a variety of processes, such as impacts from solar wind and micrometeoroids. These particles are so sparse that they rarely interact with one another or with the surface of the Moon, and they quickly escape into space due to the Moon's weak gravity.
True or False: The thinnest layer of Earth's interior is the crust.
True
True or False: While the radiation from solar flares reaches Earth in just over 8 minutes, the material from a coronal mass ejection (CME) can take several days to reach us.
True
The Sun's Radiation Energy
The Sun's radiation energy is a type of electromagnetic energy that is produced as a result of nuclear fusion reactions that occur in its core. These reactions release a tremendous amount of energy in the form of high-energy particles and photons, which are emitted from the Sun and travel through space at the speed of light. The Sun emits a wide range of electromagnetic radiation, including visible light, ultraviolet radiation, X-rays, and gamma rays. The amount and type of radiation emitted by the Sun depend on its temperature and other physical properties, as well as on the conditions of the surrounding environment.
Nuclear reactions which power the Sun occur in which region?
The core
7. How did our determination that Earth is several billion years old limit the possible energy sources for the Sun?
The determination that the Earth is several billion years old limited the possible energy sources for the Sun because it ruled out the possibility that the Sun could be powered by chemical reactions, such as combustion or oxidation, which would only be able to sustain the Sun's energy output for a relatively short period of time, on the order of millions of years.
Where does the fusion of hydrogen to helium occur and what is the temperature needed?
The fusion of hydrogen to helium occurs in the cores of stars, including our own sun. In the sun's core, temperatures reach about 15 million degrees Celsius (27 million degrees Fahrenheit) and pressures are extreme, allowing for the fusion of hydrogen into helium. The high temperatures and pressures are necessary to overcome the electrostatic repulsion between the positively charged protons in the hydrogen nuclei. At such high temperatures, the hydrogen nuclei have enough kinetic energy to overcome this repulsion and get close enough together for the strong nuclear force to bind them together into a helium nucleus.
Greenhouse gasses and CO2
The greenhouse effect is primarily caused by certain gases in the atmosphere, known as greenhouse gases, such as carbon dioxide (CO2), methane (CH4), and water vapor (H2O). These gases absorb some of the energy from the sun that is radiated back from the Earth's surface, trapping it in the atmosphere and preventing it from escaping into space. This leads to an increase in the overall temperature of the planet, known as global warming. While the greenhouse effect is a natural process that has been occurring for millions of years, human activities, such as burning fossil fuels and deforestation, have increased the concentration of greenhouse gases in the atmosphere. This has led to an enhanced greenhouse effect and an increase in the Earth's average surface temperature, which is causing climate change
Explain why the greenhouse effect is important to life on Earth, but is also a cause for concern in the future.
The greenhouse effect is that gasses in the atmosphere get heated by the sun, preventing them from escaping into space. This helps keep the earth warm enough to support life. Without it Earth would be too cold to support life. However, an increase in human activities has led to an increase in the concentration of greenhouse gasses which caused the average temperature to increase. This can lead to rising sea levels, severe weather, floods, droughts, and adverse effects on human health in the future.
The co-accretion theory
The moon formed together with (but independent of) Earth, as we believe many moons of the outer planets formed.
The Capture theory
The moon was formed elsewhere in the solar system and was captured by earth
The fission theory
The moon was once a part of earth , but somehow separated from it early in their history.
Which part of the Sun's atmosphere has the lowest temperature?
The photosphere
Provide reasons that scientists believe Olympus Mons, the largest volcano in the solar system, could still experience periods of activity.
There are no craters on Olympus mons, suggesting that it has been active recently.
Describe the "giant impact" hypothesis
There were giant of material - objects of essentially planetary mass - were orbiting in the inner solar system at the time the terrestrial planets formed. The object envisions earth being struck obliquely by an object aproximately one thenth Earth's mass. Such a massive impact ejected massive amounts of material into space. This ejected material formed a ring around earth. the ring condensed into the moon. We know this is the case because the moon's raw material is derived from the mantle of earth and the projectile, the absence of metals is easily understood. Second, most of the volatile elements would have been lost during the high temperature phase following impact explaining the lack of these materials.
Which large moon in the outer solar system actual orbits in a retrograde fashion (clockwise), suggesting it might have been captured by its host planet?
Triton
True or False: Although they look similar on the surface, the interiors of Mercury and our Moon are vastly different.
True
True or False: Neutrinos created in the core of the Sun travel to the surface at approximately the speed of light, while energy in the form of photons can take a hundred thousand years or more to escape.
True
The rotational motion of which of the giant planets shows evidence that something large must have struck it during the early formation of the solar system?
Uranus
What are the planets from hottest to coldest? (terrestrials)
Venus - with an average surface temperature of 462°C (864°F), Venus is the hottest planet in our solar system. Mercury - despite being closest to the sun, Mercury's lack of atmosphere means that it has a highly variable surface temperature that ranges from -173°C (-280°F) at night to 427°C (800°F) during the day. Earth - with an average surface temperature of 14°C (57°F), Earth is much cooler than Venus and Mercury. Mars - with an average surface temperature of -63°C (-81°F), Mars is much colder than Earth.
How do we know about Earth's interior layers?
We can test this with seismic waves. These are waves that spread through the interior of the earth from earthquakes or explosion sites. Act like soundwaves. Frequencies vary depending on the composition
The slow, fluid-like motion of Earth's mantle is caused by hotter portions moving upward and cooler portions sinking, a process known as __________
a.) Convection
Which gas giants have rings?
all of them
Scientists believe a number of meteorites that have been recovered on Earth originated from Mars. Which of the following is evidence of this? a.) They are mostly sedimentary in nature, similar to rocks on Mars. b.) Gases trapped in the rock match the atmosphere of Mars. c.) They have strong magnetic properties, similar to rocks found on Mars. d.) They have "Made in the Tharsis Region" stamped on them.
b.) Gases trapped in the rock match the atmosphere of Mars.
The best evidence that Earth has a liquid metallic region of its core is
c.) Earth's substantial magnetic field.
Venus's atmosphere a.) is similar in composition to Earth, but thousands of times more massive. b.) contains a thick layer of clouds composed mostly of water vapor. c.) results in a surface pressure that is 90x that of Earth. d.) all of the above are true.
c.) results in a surface pressure that is 90x that of Earth.
Astronomers have concluded that the Sun's surface activity varies in a regular fashion. Which of the following statements about this solar cycle is TRUE? a.) The core temperature of the Sun varies approximately every 11 years, causing these changes. b.) The number of sunspots reaches a maximum approximately every 22 years c.) When sunspots are at a minimum, we get the largest number of flares and prominences d.) From one cycle to the next, the magnetic polarity of sunspots is reordered, such that if North polarity spots lead South polarity spots the first 11 years, South polarities lead North polarities the next 11 years.
d.) From one cycle to the next, the magnetic polarity of sunspots is reordered, such that if North polarity spots lead South polarity spots the first 11 years, South polarities lead North polarities the next 11 years.
Which one of the following statements regarding Earth and the Moon is correct? a.) The Moon is more dense than Earth. b.) The rotational period of the Moon is the same as that of Earth. c.) The Moon has a molten iron region of its core, similar to that of Earth. d.) Moon rocks brought back from Apollo missions are generally older than the rocks we find on the surface of Earth.
d.) Moon rocks brought back from Apollo missions are generally older than the rocks we find on the surface of Earth.
Crater counts on the surface of Venus indicate that its surface a.) was once completely covered with water-filled oceans. b.) it is constantly being bombarded by small micrometeorites. c.) has been unchanged since Venus first formed. d.) is only a few hundred million years old.
d.) is only a few hundred million years old.
True or False: Global climate change over the past 50 years seems to be well-correlated with changes in solar activity.
false
True or False: Russian cosmonauts landed on the back side of the moon in 1959 in the spacecraft Luna 3, setting foot on the moon 10 years prior to the first American astronauts.
false
True or False: The strong magnetic fields of Jupiter and Saturn are thought to be caused by motions in very large molten iron cores.
false
The atmospheres of the giant planets are dominated by which element and its associated compounds?
hydrogen
What is the source of the fine, powdery dust found on the Moon's surface?
it is the result of many impacts, breaking surface rocks apart over billions of years
Lunar Maria
large, dark, flat areas on the Moon's surface that are visible to the naked eye from Earth. They are formed by ancient volcanic eruptions that filled large impact basins with basaltic lava. The word "mare" means "sea" in Latin, and the early astronomers who named them thought they were large bodies of water on the Moon's surface.
Greenhouse gases (CO2, water vapor, and methane) make up ___________ of our atmosphere.
less than 1%
Solar Prominences
olar prominences are large, bright features that extend outward from the Sun's surface into its outer atmosphere, called the corona. They are composed of hot plasma, a gas made up of electrically charged particles, primarily hydrogen and helium. There are two main types of solar prominences: quiescent and eruptive. Quiescent prominences are relatively stable and can last for weeks or even months, while eruptive prominences are more dynamic and can rapidly change or even launch material into space in the form of a coronal mass ejection. Solar prominences are closely related to the Sun's magnetic field, which plays a crucial role in their formation and behavior. They are typically found near areas of strong magnetic fields, such as sunspots or active regions, and can be shaped and controlled by the complex interactions between the magnetic field and the surrounding plasma.
How do astronomers know that the age of the solar system is about 4.5 billion years old?
radioactive dating of the primitive meteorites indicates they have that age (since they are left-over building blocks of the solar system)
What characteristic of the solar nebula, more than any other, determined which materials could condense at different distances from the Sun?
temperature at a given location
The reason that worlds like the Earth are differentiated is that
the continuing impacts on a growing protoplanet eventually melted the entire body
A key difference between the protoplanets that formed in the outer solar system and those that formed in the inner solar system was that:
those in the outer solar system were in a place where ice, not just rock, condensed and thus could grow larger
Among solid worlds, which type of is most likely to still have significant geological activity? a.) those that are the smallest (and thus easiest to heat) b.) those that have strong magnetic fields c.) those that have a moon (satellite) d.) those that are the largest (and retain heat the best) e.) those that are farthest from the Sun
those that are the largest (and retain heat the best)
Weather systems on Earth occur in which layer of the atmosphere?
troposphere
True or False: Although Saturn is very large, its average density is less than that of water on Earth.
true
True or False: Helium was actually first seen in the spectrum of the Sun prior to its discovery on Earth.
true
True or False: The vast majority of the light we see from the Sun comes from the layer called the photosphere.
true
How has the distance between Earth and the Sun been determined to high accuracy?
using radar reflection measurements of distances to terrestrial planets
Planets in order of rotating fastest to slowest (and backward) for Gas Giants
1. Jupiter - 9 hours 56 minutes 2. Saturn - 10 hours 39 minutes 3. Uranus - 17 hours 14 minutes 4. Neptune - 16 hours 6 minutes
What are some characteristics of the magnetic field?
1.) Extends into surrounding space 2.) Traps charged particles from the sun in our magnetosphere. the magnetosphere extends 60,000 kilometers. Contains the van allen belts
How do you date planetary surfaces by counting impact craters?
1.) Identify a region of the planet's surface that appears to be undisturbed by tectonic or volcanic activity, which would erase or modify the impact craters. 2.) Count the number of impact craters in the region of interest. To be useful for dating, the craters should be large enough to be visible and have well-defined rims and ejecta blankets. 3.) Compare the number of impact craters in the region to a known cratering rate for that planet, which is determined by the size and population of impactors in the planet's vicinity. This gives an estimate of the age of the surface. 4.) Refine the estimate of the surface age by considering other factors that may have affected the surface, such as erosion or deposition of material.
Describe the process of fusion of hydrogen to helium?
1.) The process can be broken down into several steps: Proton-Proton Chain: In the first step, two hydrogen nuclei (protons) fuse together to form a deuterium nucleus (a hydrogen isotope with one proton and one neutron) and a positron (a positively charged electron) and a neutrino. This is known as the proton-proton chain, which is the dominant process for hydrogen fusion in the sun. 2.) Formation of Helium-3: In the second step, a deuterium nucleus fuses with a proton to form a helium-3 nucleus (two protons and one neutron), releasing a gamma ray in the process. 3.) Formation of Helium-4: In the final step, two helium-3 nuclei combine to form a single helium-4 nucleus (two protons and two neutrons), releasing two protons in the process. This step releases a large amount of energy, which is what powers the sun and other stars.
The pressure under the surface of the oceans increases by approximately 1 bar (standard atmospheric pressure at sea level) for every __________ in depth.
10 meters
Planets in order of rotating fastest to slowest (and backward) for terrestrials
5. Earth - 23 hours 56 minutes 6. Venus - 243 Earth days (retrograde rotation, meaning it rotates backwards) 7. Mars - 24 hours 37 minutes 8. Mercury - 58.6 Earth days
Which gas giants have active weather systems in their atmospheres?
All four of the gas giants in our solar system - Jupiter, Saturn, Uranus, and Neptune - have active weather systems in their atmospheres. Jupiter is particularly well-known for its intense and long-lived storms, such as the Great Red Spot and the smaller White Oval storms, as well as its numerous smaller storms and weather features. Saturn also has a number of storm systems, including the hexagonal-shaped storm at its north pole and a persistent storm near its south pole. Uranus and Neptune, which are both ice giants, also have active weather systems in their atmospheres, but they are less well-studied than those of Jupiter and Saturn. Uranus has been observed to have bright cloud features and storm systems, while Neptune is known for its Great Dark Spot, a large storm that was observed by the Voyager 2 spacecraft in 1989. The active weather systems in the gas giants' atmospheres are driven by a combination of factors, including internal heat from the planets themselves, atmospheric circulation patterns, and interactions with the planets' magnetic fields.
Differences between near and far sides of the moon?
Appearance: One of the most noticeable differences between the two sides is their appearance. The near side of the Moon is relatively smooth and has large, dark areas called maria, while the far side is heavily cratered and mountainous, with fewer maria. This is because the Moon's rotation is synchronous with its orbit around the Earth, so the near side has been bombarded by more meteoroids over time, resulting in more volcanic activity and the formation of the maria. Geology: The two sides also have different geological features. The near side has a thinner crust and a higher concentration of radioactive elements, which have contributed to the formation of the maria. The far side has a thicker crust and more extensive highlands, which are thought to have formed during the Moon's early history when it was subjected to intense impacts from asteroids and other objects. Composition: Studies of lunar samples returned by the Apollo missions have shown that there are also differences in the composition of the two sides. The far side is richer in aluminum and calcium, while the near side has more iron and titanium. This is thought to be due to the presence of a large impact basin on the far side, called the South Pole-Aitken Basin, which may have excavated material from deeper within the Moon's crust.
Conservation of Angular Momentum
Conservation of angular momentum is a fundamental principle in physics that states that the total angular momentum of a system remains constant if no external torque acts on the system. Angular momentum is a vector quantity that describes the rotational motion of an object or a system of objects around a fixed axis or point. It depends on the mass, speed, and distance of the objects from the axis of rotation. When an object or a system of objects rotates around an axis, its angular momentum is conserved because the total torque acting on the system is zero. This means that the product of the moment of inertia (a measure of how difficult it is to change the rotation of an object) and the angular velocity (the rate at which an object rotates) remains constant.
What are coronal mass ejections?
Coronal mass ejections (CMEs) are massive, explosive eruptions of plasma and magnetic field from the Sun's corona, or outer atmosphere. These events can release billions of tons of material into space at speeds of up to several million miles per hour. CMEs are closely related to solar flares, and often occur in conjunction with them. The energy released during a flare can trigger a CME by destabilizing the surrounding magnetic field, causing it to erupt outward from the Sun's surface. CMEs can have a range of effects on Earth, including creating geomagnetic storms that can interfere with satellite and communication systems, disrupt power grids, and increase radiation exposure for astronauts and airline passengers. They can also create spectacular displays of auroras, or Northern and Southern Lights, at high latitudes.
What are the layers of the Earth?
Crust: roughly 6 kilometers thick and is comprised of volcanic basalt rock Mantle: roughly 2900 km thick and is more or less solid Core: roughly 1200 kilometers thick and is liquid on the outside and is probably solid on the inside. Comprised of iron, nickel, and Sulphur Inner core: 746 miles thick and is probably solid because of the pressure.
Planetary composition of the gas giants?
Jupiter, the largest planet in our solar system, is about 90% hydrogen and 10% helium, with trace amounts of methane, ammonia, water vapor, and other compounds. Saturn, the second-largest gas giant, has a similar composition, with about 96% hydrogen and 3% helium, along with small amounts of methane, ammonia, and other gases. Uranus and Neptune, the ice giant planets, have somewhat different compositions, with more ices and other compounds in their atmospheres. Uranus is about 83% hydrogen, 15% helium, and 2% methane and other compounds, while Neptune is about 80% hydrogen, 19% helium, and 1% methane and other gases.
How do we determine the mass of the sun?
Mass: The mass of the Sun can be determined using Kepler's laws of planetary motion, which describe the orbital motion of planets around the Sun. By measuring the orbital period and distance of a planet or satellite, astronomers can calculate the mass of the Sun using the law of gravitation.
Which planets have magnetic fields, what does that tell us?
Mercury - has a weak magnetic field. Venus - does not have a significant magnetic field. Earth - has a strong magnetic field that protects the planet from harmful solar radiation and solar wind. Mars - has a weak magnetic field. Jupiter - has a very strong magnetic field that is the largest in our solar system. Saturn - has a strong magnetic field that is slightly weaker than Jupiter's. Uranus - has a weak magnetic field that is tilted at a 59-degree angle relative to the planet's axis of rotation. Neptune - has a strong magnetic field that is similar in strength to Saturn's. The presence of a magnetic field tells us that a planet has a liquid or partially liquid metallic core, which generates the magnetic field as it rotates.
Which planets have atmospheres? Are they thick or thin? And what are they composed of?
Mercury - very thin atmosphere consisting of just trace amounts of hydrogen, helium, and other gases. Venus - thick atmosphere composed mostly of carbon dioxide (96%) with smaller amounts of nitrogen, sulfur dioxide, and trace amounts of other gases. Earth - a thick atmosphere composed mostly of nitrogen (78%) and oxygen (21%) with smaller amounts of other gases such as argon, carbon dioxide, and neon. Mars - a thin atmosphere composed mostly of carbon dioxide (95%) with small amounts of nitrogen, argon, and trace amounts of oxygen and other gases. Jupiter - thick atmosphere composed mostly of hydrogen (75%) and helium (24%) with small amounts of methane, ammonia, and other gases. Saturn - thick atmosphere composed mostly of hydrogen (96%) and helium (3%) with small amounts of methane and other gases. Uranus - a thin atmosphere composed mostly of hydrogen (83%) and helium (15%) with small amounts of methane and other gases. Neptune - a thick atmosphere composed mostly of hydrogen (80%) and helium (19%) with small amounts of methane and other gases.
Nuclear fusion
Nuclear fusion is a process by which atomic nuclei come together to form a heavier nucleus, releasing a tremendous amount of energy in the process. This process is the fundamental source of energy production in stars, including our own Sun. In nuclear fusion, atomic nuclei are brought together under conditions of extremely high temperature and pressure, causing them to fuse and form a heavier nucleus. This process releases a large amount of energy in the form of radiation and thermal energy, as well as the production of subatomic particles. Nuclear fusion occurs when the repulsive electric force between positively charged atomic nuclei can be overcome by the strong nuclear force, which holds the nucleus together. However, since atomic nuclei are positively charged, they naturally repel each other and require a great deal of energy to be brought close enough together for fusion to occur. One of the most common fusion reactions in stars involves the fusion of hydrogen nuclei (protons) to form helium nuclei. This reaction involves a series of steps, with two protons first fusing to form a deuterium nucleus (a hydrogen isotope with one proton and one neutron), which then fuses with another proton to form a helium-3 nucleus (two protons and one neutron). Finally, two helium-3 nuclei combine to form a single helium-4 nucleus (two protons and two neutrons), releasing a large amount of energy in the process.
The Sun's Kinetic Energy
One way to describe the Sun's kinetic energy is to consider the motion of its constituent particles. At the core of the Sun, temperatures are estimated to be around 15 million degrees Celsius, which causes hydrogen atoms to collide and fuse together to form helium. This process releases a tremendous amount of energy in the form of high-speed particles, such as protons and electrons, which are released into the surrounding plasma. The kinetic energy of these particles is related to their mass and velocity, with more massive particles and higher velocities corresponding to greater kinetic energy. In the case of the Sun, the sheer number and speed of the particles produced by nuclear fusion reactions contribute to its enormous kinetic energy.
What are the primary types of rock that make up Earth's crust?
Sedimentary Rocks: are made up of fragments of igneous rock or the shells of living organisms deposited by wind or water and cemented together without melting. Metamorphic rock: produced when high temperature or pressure alters igneous or sedimentary rock physically or chemically. Igneous: Rock that is cooled from a molten state
Describe the structure of the moon
Structure: The Moon has a layered structure with a core, mantle, and crust. The core is thought to be small and solid, made up of iron and some other metals. The mantle is a thick layer of rock and extends from the core to the surface. The crust is the outermost layer of the Moon and ranges in thickness from about 30 to 40 km on the near side to about 10 to 20 km on the far side. The Moon's surface is covered by craters, mountains, and large, flat plains called maria. These features were formed by impacts from meteorites and volcanic activity early in the Moon's history. The maria are composed of dark, iron-rich basaltic rocks, while the highlands are made up of lighter-colored anorthosite and other minerals.
Does the moon have a magnetic field?
The Moon has a very weak magnetic field, much weaker than the Earth's magnetic field. The Moon's magnetic field is thought to be generated by small regions of magnetized rocks within its crust, rather than by a global dynamo like the one that produces Earth's magnetic field. The Moon's magnetic field is not strong enough to provide significant protection from the solar wind or to create a global magnetosphere like the one surrounding the Earth.
What elements are abundant in the Sun?
The Sun is composed primarily of hydrogen and helium, which together account for over 99% of its elemental composition by mass. Other elements are present in much smaller amounts, with oxygen, carbon, neon, and nitrogen being the next most abundant. Trace amounts of other elements such as iron, nickel, and calcium are also present.
What are the Auroras?
The Sun sends us more than heat and light; it sends lots of other energy and small particles our way. The protective magnetic field around Earth shields us from most of the energy and particles, and we don't even notice them. But the Sun doesn't send the same amount of energy all the time. There is a constant streaming solar wind and there are also solar storms. During one kind of solar storm called a coronal mass ejection, the Sun burps out a huge bubble of electrified gas that can travel through space at high speeds. There, the particles interact with gases in our atmosphere resulting in beautiful displays of light in the sky. Oxygen gives off green and red light. Nitrogen glows blue and purple. aurora borealis or northern lights. If you're near the South Pole, it is called an aurora australis or the southern lights.
The Sun's Thermal Energy
The Sun's thermal energy is the result of the enormous heat produced by nuclear fusion reactions in its core. These reactions convert hydrogen into helium, releasing a tremendous amount of energy in the process. The energy generated by nuclear fusion reactions in the Sun's core creates an enormous amount of heat that travels outward through the Sun's layers. The heat is transferred primarily through a process called radiation, in which energy is carried by electromagnetic waves, such as visible light and infrared radiation. As the heat travels outward, it causes the temperature of the Sun's outer layers to rise, creating a glowing ball of hot gas that we see in the sky. The temperature of the Sun's outer layers is estimated to be around 5,500 degrees Celsius, or approximately 9,932 degrees Fahrenheit.
Major constituents of the Atmosphere
The atmosphere consists of 78% nitrogen, 21% oxygen, 1% argon, with traces of water vapor , carbon dioxide, and other gasses.
Ability to condense hydrogen, helium, and ices by Giant Planets
The different temperatures at which different substances can condense played a crucial role in the formation of the solar system. The inner regions of the protoplanetary disk, where the temperature was higher, only allowed refractory materials, such as metals and silicates, to condense into solid particles. The outer regions, where the temperature was lower, allowed for volatile substances to condense as well, forming a variety of ices that contributed to the formation of the outer planets and their moons.
What is the relationship of sunspots to the Sun's magnetic field?
The magnetic field in and around sunspots is complex and dynamic, with multiple polarities and varying strengths. The sunspot cycle is driven by the cyclic variation of the Sun's magnetic field, which reaches a maximum every 11 years and then reverses its polarity, with the north and south magnetic poles switching places. Sunspots are associated with other solar phenomena such as flares and coronal mass ejections, which can release large amounts of energy and charged particles into space. These events are triggered by the complex interactions of the Sun's magnetic field with the surrounding gases, and can have significant effects on the space environment around the Earth.
What is the relationship of sunspot cycle to Auroras on Earth?
The sunspot cycle can have a significant effect on the occurrence and intensity of auroras on Earth. Auroras, also known as the northern and southern lights, are colorful displays of light in the Earth's atmosphere that are produced when charged particles from the Sun interact with the Earth's magnetic field. During periods of high solar activity, such as the peak of the sunspot cycle, there is an increase in the occurrence and intensity of solar flares and coronal mass ejections, which release large amounts of charged particles into space. When these particles reach the Earth, they interact with the planet's magnetic field, causing disturbances in the magnetosphere and ionosphere that can trigger auroras. The auroras tend to be most intense and frequent at high latitudes, such as in the regions around the magnetic poles, where the Earth's magnetic field is most strongly influenced by the charged particles from the Sun. The intensity and frequency of auroras can vary greatly during the sunspot cycle, with the most spectacular displays occurring during periods of high solar activity.
What is the time frame of the sunspot cycle?
The sunspot cycle, also known as the solar cycle, is a periodic variation in the number of sunspots, as well as other solar phenomena such as solar flares and coronal mass ejections, that occurs approximately every 11 years. The cycle is characterized by a period of low activity, during which the number of sunspots is relatively small, followed by a period of high activity, during which the number of sunspots increases and reaches a maximum, after which activity declines again.
How do you date planetary surfaces using radioactivity?
This method relies on the fact that some naturally occurring elements in rocks and minerals, such as uranium, thorium, and potassium, decay over time into more stable forms at a known rate. By measuring the amounts of radioactive isotopes and their decay products in a rock sample, scientists can calculate how long it has been since the rock was last heated or cooled, providing an estimate of the age of the surface.
What are some historical ideas of the sun's energy production. Why don't they fit our current understanding?
Throughout history, there have been various ideas and theories about the Sun's energy production. One of the earliest ideas was that the Sun was powered by burning fuel, such as coal or wood, in a process similar to combustion on Earth. Another idea was that the Sun was simply a very hot object, slowly cooling down over time. However, these early ideas were eventually disproven by scientific observations and measurements. In the early 20th century, scientists began to understand the process of nuclear fusion, which is now recognized as the primary source of the Sun's energy. One of the main reasons why these early ideas do not fit with our current understanding is that they do not account for the massive amounts of energy that are produced by the Sun. Burning fuel, such as coal or wood, simply cannot generate the amount of energy required to sustain the Sun's heat and light over millions of years. Additionally, the idea that the Sun is simply a hot object cooling down over time does not explain why its temperature has remained relatively constant over billions of years.
Describe the difference between Earth's atmospheric regions?
Troposphere: Roughly 0-10km where clouds form and planes fly. Air is warm and heated from the surface. Stratosphere: 10-50km above the surface. very cold and free of clouds. Mesosphere: altitude of around 50 to 85 kilometers (31 to 53 miles) above the Earth's surface. The mesosphere is the layer of the atmosphere where most meteors burn up upon entry into the Earth's atmosphere. Ionosphere: 60 kilometers (37 miles) to 1,000 kilometers (620 miles) above the Earth's surface. It is named after the fact that it contains a high concentration of ions and free electrons, which are formed by the ionization of atmospheric gases by solar radiation.
Which gas giants have odd rotations or tilted axes?
Uranus - Uranus has a highly tilted axis, with its magnetic and rotational poles nearly in the same plane. This means that its poles receive much more sunlight than the equator, causing unusual weather patterns and seasonal variations. Neptune - While Neptune's axis is tilted like Earth's, it is tilted at an extreme angle of 28.32 degrees. This causes the planet's magnetic field to be offset from its center, creating a unique magnetic field structure. Jupiter - While not tilted to the same extent as Uranus, Jupiter's axis is still tilted by about 3 degrees, which is enough to create noticeable weather patterns in its atmosphere. Saturn - Saturn's rotation is also somewhat unusual, as its atmosphere rotates at different speeds at different latitudes. This causes distinctive bands and stripes in its atmosphere and creates powerful storms such as the hexagonal storm at its north pole.
Which terrestrial planets could possibly contain life?
Venus, for example, has a harsh environment with a thick, toxic atmosphere and surface temperatures hot enough to melt lead. However, there is evidence of possible microbial life in the upper layers of Venus' atmosphere, where conditions are less extreme. Mars is also of interest in the search for life, as it has a thin atmosphere and a history of liquid water on its surface. There is evidence that Mars once had a more Earth-like environment, and scientists are investigating whether life may have existed on the planet in the past or could survive in subsurface environments today.
Explain the difference between weather and climate
Weather refers to the atmospheric conditions, such as temperature, humidity, precipitation, wind, and cloud cover, that occur in a specific location and over a short period of time, typically ranging from a few minutes to a few weeks. Weather is highly variable and can change rapidly, even within a single day. For example, a sunny morning could turn into a rainy afternoon. Climate, on the other hand, refers to the long-term patterns and averages of weather conditions in a particular region over a period of several decades or more. It takes into account factors such as temperature, precipitation, humidity, and wind, among others. Climate is a more stable and predictable phenomenon than weather and is determined by various factors such as latitude, altitude, topography, ocean currents, and prevailing winds.
Describe the relationship between fault zones and mountain building
When tectonic plates collide, the movement creates pressure and strain, which can result in rocks breaking and fault zones forming. These fault zones can create uplifts and mountain ranges as the plates continue to move and force sections of the Earth's crust upward. This is known as compressional tectonics, and it is the primary mechanism behind the formation of many of the world's most prominent mountain ranges, including the Himalayas and the Andes. When tectonic plates diverge, the resulting tension creates rift zones, which can eventually lead to the formation of mountains as magma rises from the mantle and cools, creating new land masses. This process is known as extensional tectonics, and it is responsible for the formation of mid-ocean ridges, as well as volcanic islands and mountain ranges, such as the Hawaiian Islands.
The back side of the Moon (the one we can't see from Earth), a.) always stays hundreds of degrees colder than the front side. b.) is dominated by lunar highlands, with very few maria. c.) contains several active volcanoes. d.) none of these - and the back side of the Moon is visible from Earth as often as the front side.
b.) is dominated by lunar highlands, with very few maria.
ault zones are regions where Earth's tectonic plates a.) spread apart from each other, allowing the formation of new crust. b.) collide so that one slides underneath the other, destroying old crust in the process. c.) attempt to slide parallel to each other, building up stresses that cause earthquakes when released. d.) blame each other for everything bad that happens to them.
c.) attempt to slide parallel to each other, building up stresses that cause earthquakes when released.
True or False: With the exception of the most recent 200 years (the industrial age), Earth's atmosphere has remained pretty much the same for the past 4.5 billion years.
false
