HOMEWORK

Makail Betsill
@02754728
Section: 04
Due Wednesday Dec. 3rd 2014
Planetary Science Lecture: Astronomy HW

Chap 6 pgs. 186-7: 3, 4, 5, 10, 13, 15, 16, 19, 20, 23

3. What are the four major features of our solar system that provide clues to how it was formed? Describe each one briefly.
Four major features provide clues:
(1) The Sun, planets, and large moons generally rotate and orbit in a very organized way.
(2) With the exception of Pluto, the planets divide clearly into two groups: terrestrial and jovian.
(3) The solar system contains huge numbers of asteroids and comets.
(4) There are some notable exceptions to these general patterns.
4. What are the basic differences between the "terrestrial and jovian" planets? Which planets fall into each group?
Terrestrial - four planets of the inner solar system: Mercury Venus Earth and Mars They are small, dense with rocky surfaces and an abundance of metals in their cores. They also have few moons, if any and no rings. closer to the Sun
Jovian - Four large planets of the outer solar system: Jupiter, Saturn, Uranus and Neptune They are much larger in size and average density than the terrestrial planets. They have rings and numerous moons. they are made mostly of hydrogen, helium hydrogen compounds.

5. What is the Nebular Theory, and why is it widely accepted by scientists today?
Holds that the solar system formed from the gravitational collapse of a great cloud of gas and dust, successfully explains all the major features of our solar system. The nebular theory of solar system formation gained wide acceptance because of its success in explaining the major characteristics of our solar system.

10. Briefly describe the process by which terrestrial planets are thought to have formed. How was the formation of jovian planets similar to that of the terrestrial planets?
Terrestrial planets formed inside the frost line, where accretion allowed tiny, solid grains of metal and rock to grow into planetesimals that ultimately merged to make the planets we see today
Similar-The formation was similar due to accretion which is the process of small solid rock"seed" as they grew into planets and once the gases came from a solid material. The two also have planetesimals which are "pieces of planets".
Different- As each jovian planet is wrapped around it own disk of gas but terrestrials don't have this.
Moons- Because they were captured in the planetary orbit when they lost energy to drag in the extended disks of gas that surrounded these planets as they formed. they would have been slowed by the friction with gas. It slowed planetesimals orbital energy enough to make it an orbiting moon.

13. How do we think the Moon formed, and what evidence supports this hypothesis?
Answer: We look at the impact at a speed and angle that would have blasted rock from Earth's outer layers in space. According to computer simulations, this material could have collected into orbit around out planet, and accretion within this rind of debris could have formed the Moon. Evidence to support this hypothesis comes from two features of the Moon's composition like the moon's overall composition is similar to Earth's and the Moon has a much smaller proportion of easily vaporized ingredients such as water than Earth.
15. Describe three major methods used to detect extrasolar planets indirectly what does each method tell you about the planet
1. observing the radiation and light coming from the star that the planet is orbiting, the planet will come in between us and the star and cause a dimming in the stars light. this method will tell you how fast the planet is revolving around the star

2, observing the gravitational pull that the planet has of the surrounding bodies. or, the "wobble" effect it has on its star this method will tell you how big or dense the planet is by the gravitational field it produces.

3. detecting radio waves coming from the planet indicates intelligent life is on the planet

16. Why is the direct detection of extrasolar planets so difficult?
Because extrasolar planets are far away and the stars those extrasolar planets rotate about overwhelm planetary light
19. A solar system is discovered with four large jovian planets in its inner region and seven small terrestrial planets in its outer reaches.
SURPRISING
The terrestrial planets (Rocky planets that are composed primarily of silicate rocks and/or metals).
They would not have formed in the outer solar system as there would be a lot more ice, and would thus resemble Plutoids – objects like Pluto composed more of icy materials. Jovian planets or gas giants, have to form at a certain distance from the star, where it is cold enough for hydrogen compounds to condense into solid ice grains, from which a planet will form. This is known as the ice line and exists around the area of the asteroid belt. Of the extrasolar planets found, most have been what are known as hot Jupiter’s. Jupiter sized planets close to the star. It is not fully known how this occurs, but migration from it’s “birth” to it’s current position is the favoured theory. However, with our current technology, only these “hot Jupiter's” are detectable and “normal” terrestrial planets could be hiding amongst them. So for four gas giants to be close to the star is unlikely, one or two, maybe but four is unlikely. Ditto seven terrestrial planets in the outer regions is not possible, but seven icy worlds would be.
Mathematically it's not surprising. The bigger planets could orbit at any distance. The closer they are fits the spiral pattern you'd see in a galaxy, with most of the mass in the center. But that doesn't mean they can't exist elsewhere.
20. A solar system has 10 planets that all orbit the star in approximately the same plane. However, five planets orbit in one direction (e.g., counterclockwise), while the other five orbit in the opposite direction (e.g., clockwise).
Surprising
23. A solar system has several planets similar in composition to the Jovian planets of our solar system but similar in mass to the terrestrial planets of our solar system.
Surprising

Chap 7 pg. 231: 1, 4, 5, 18, 19, 25, 28,30

1. What are Earth's basic layers by composition? What do we mean by lithosphere, and why isn't it listed as one of the three layers by composition?
Core: highest-density material -> metals
Mantle: rocky material of moderate density -> mostly minerals
Crust: lowest density rock
Lithosphere is the outer layer which consists of relatively cool and rigid rock that floats on warmer, softer rock
4. Why does Earth have a global magnetic field? What is the magnetosphere? because of Earth's interior heat, generated by the motions of molten metal in its liquid outer core; charged particles move with the molten metal in its liquid outer core --> liquid metal rises and falls.
Magnetosphere deflects most of the charged particles rom the Sun
5. Define each of the 4 major geological processes, and give examples of features on Earth shaped by each process.
Impact cratering: vaporize solid rock and blast out a crater
Volcanism: played a role in erasing impact craters; Earth's atmosphere and oceans were made from gases released form the interior by volcanic outgassing; dependent on a planets size because require internal heat; outgassing released water and gases
Tectonics: direct result of mantle convection; depend on planets size because require internal heat
Erosion: played a role in erasing impact craters; strong winds are driven by our planet's rapid rotation
18. Four unique features on Earth in comparison to other terrestrial worlds.
Surface Liquid Water: Earth is the only planet on which temperature and pressure conditions allow surface water to be stable as liquid.
Atmospheric oxygen: Earth is the only planet with significant oxygen in its atmosphere and ozone layer.
Plate tectonics: Earth is the only planet with a surface shaped largely by this distinctive type of tectonics.
Climate stability: Climate has remained relatively stable throughout its history.
19. What is plate tectonics? How does it change the arrangement of continents with time?
Earth’s lithosphere is broken up into more than a dozen plates that move about through the action that we call plate tectonics. On average plates move at speeds of only a few centimeters per year.
25. A venus radar mapper discovers extensive regions of layered sedimentary rocks, similar to those found on earth : SURPRISING
28. Clear cutting in the amazon rain forest on erth exposes vast regions of ancient terrain that is as heavily cratered as the lunar highlands.
Surprising
30. We find a planet in another solar system that has an earth like atmosphere with plentiful oxygen but no life of any kind.
Surprising

Chap 8 pg. 257-8: 2, 4, 7, 9, 12, 15, 19 23

1. Briefly describe how differences in composition among the jovian planets can be traced to their formation.
Jovian planets formed in the outer solar system, where it was cold enough for hydrogen compounds to condense into ices. This caused them to grow to large size - left to gravity, it drew in hydrogen & helium gas. Thus differences in composition stem from the amount of hydrogen and helium gas they captured.
2. Why is Jupiter so much more dense than Saturn? Could a planet be smaller in size than Jupiter but greater in mass?
The extra mass of Jupiter compresses its interior to a much higher density (The pillow effect) Yes
7. Briefly describe how we categorize jovian moons by size. What is the origin of most of the medium -size and large moons? What is the origin of many of the small moons?
Small moons less than 300 kilometers, medium moons from 300 to 1500 kilometers and large moons more than 1500 kilometers in diameter.
Most formed by accretion within the disks of gas surrounding individual jovian planets (always keep the same face towards their planet)
Most are captured asteroids or comets
9. Describe the atmosphere of Titan. What did the Cassini/Huygens mission learn about Titan's surface?
It is so thick it hides the surface from view. 90% molecular nitrogen (N2 ) and argon, methane, ehtane and other hydro compounds.
River Valleys merging together, flowing down to what looks like a shoreline.Surface has a hard crust but is a bit squishy below, like sand with liquid mixed in and also ice boulders rounded by erosion - indicates a wet climate

12. What are the planetary rings made of, and how do they differ among the four jovian planets? Briefly describe the effects of gap moons and orbital resonances on ring systems.
Particles moving slowly relative to one another and occasionally colliding and at times being forced out at others. Saturn has several rings, separated by Cassini gap
Gap Moons are small moons within the rings that nudge the orbits of ring particles in a certain way. Shepard moons force particles in line. Reinforcement of the rings due to repeated gravitational tugs.

15. Surprising discovery? - Saturn's core is pockmarked with impact craters and dotted with volcanoes erupting basaltic lava
Implausible. No impactors would survive the immense pressures at the depth of Saturn's core

19. Surprising discovery? - A new moon is found orbiting Neptune in its equatorial plane and in the same direction as Neptune rotates, but its made almost entirely of materials such as iron and nickel
Implausible. Solid objects at those distances are largely icy and rocky

23. During a future mission to uranus scientists discover it is orbited by another 20 previously unknown moons.
Not surprising.

Chap 9 pgs. 281-2: 1, 2, 4, 15, 23

1. Why are asteroids, meteoroids, and comets all of special interest to astronomers who want to understand the early history and subsequent evolution of the solar system?
Asteroids, meteorites, and comets are of special interest to astronomers who want to understand the early history of the solar system because these bodies have undergone fewer changes over billions of years compared with planets and satellites. This unchanged matter still contains information about the early solar
2. How does the largest asteroid compare in size to the planets? How does the total mass of all asteroids compare to the mass of a terrestrial world? they are relatively small, if you compress all the asteroids together they would be half the size of our moon. Total mass less than any terrestrial planet.
4. What is the difference between a meteor and a meteorite? How can we distinguish a meteorite from a terrestrial rock?
A meteorite is a rock that has crashed to Earth and a meteor is a "thing in the air". flash of light caused by a particle entering our atmosphere at high speed
Dark pitted crust, some have high metal content, enough to attract a magnet hanging on a string. They contain iridium that are rare in Earth rocks.
15. Surprising discovery? - A small asteroid that orbits within the asteroid belt has an active volcano
Implausible. Asteroids are too small to be geologically active now
23. Astronomers discover three objects with the same average distance from the sun as pluto
Implausible

Chap 10 pgs. 305-6: 4, 5, 11, 16, 19, 25

4. Briefly describe the distinguishing features of each of the layers of the Sun shown in Figure 14.4.
Outside to inside: Solar wind, Corona, Chromosphere, Photosphere and Sunspots, Convection Zone, Radiation Zone, Core. Solar wind is the gas and particles ejected from the Sun. The corona is the loose atmosphere around the sun. The chromosphere is a more dense but less hot atmospheric region that has small spikes of gas jet up into it from the surface. The photosphere is the visible surface of the Sun, and the region where sunspots develop. Sun spots are cooler regions which have intense magnetic fields. Convection zone is where the energy from the core is brought upwards via convection (the rising of hotter gases and the falling of cooler gases.) The radiation zone is where energy travels to the convection zone from the core primarily via photons. The Core is where fusion happens.
5. What is the difference between nuclear fission and nuclear fusion? Which one is used in nuclear power plants? Which one does the Sun use?
Nuclear fusion and nuclear fission are two different types of energy-releasing reactions in which energy is released from high-powered atomic bonds between the particles within the nucleus. The main difference between these two processes is that fission is the splitting of an atom into two or more smaller ones while fusion is the fusing of two or more smaller atoms into a larger one. Nuclear fission is used for nuclear power plants. Nuclear fusion is used by the sun.
11. What are the neutrinos? What was the solar neutrino problem, and why do we think it has now been solved?
Neutrinos are sub-atomic particles that can pass through most matter without interacting. Early attempts to detect them only turned up a third of the amount required by predictions based on models of the Suns core. We discovered there are three types of neutrinos and that early detectors only picked up one.
16. What is the sunspot cycle? Why is it sometimes described as an 11-year cycle and a 22-year cycle? Are there long term changes in solar activity?

The sunspot cycle is a cycle in which the average number of sunspots per year gradually rises and falls, 11 years between maximums and minimums (22 per cycle.) There have been times when there are almost no sunspots, indicating that the long term changes can possibly be very drastic.
19. If fusion in the solar core ceased today,worldwide panic would break out tomorrow as the Sun began to grow dimmer. Yes, because Earth would quickly freeze over. Earth would no longer be bound to the solar system and would drift into space. Yes, because the Sun would collapse and the planets would soon follow.

25. If the sun's magnetic field somehow disappeared there would be no more sunspots on the sun, yes sunspots would soon disappear.

Chap 11, p. 330 Questions # 19, 20, 22, 24, 25, 29, 31

19. Stars that look red hot have hotter surfaces than stars that look blue.
Does not make sense, blue stars have hotter surfaces.

20. Some of the stars on the main sequence of the H-R diagram are not converting hydrogen to helium.
Does not make sense, all stars on the H-R diagram are converting hydrogen to helium.

22. Stars that begin their lives with the most mass live longer than less massive stars because they have so much more hydrogen fuel.
Does not make sense, in most cases smaller stars live longer than larger stars.

24. All giants, supergiants, and white dwarfs were once main sequence stars.
Makes sense

25. Most of the stars in the sky are more massive than the sun.
Makes sense

29. Which of these stars has the coolest surface temperatures?
C) K star

31. Which of these stars has the longest lifetime
C) main-sequence M star

Chapter 12, p. 358 visual skills check #1-4, p. 359 # 9, 13, 19, 22

Visual Skills
1. What will the suns approximate luminosity be during the subgiant stage?
10 Squared solar units
2. When the sun is a red giant what will its approximate surface temperature be?
3,000 degrees kelvin
3. Just before the sun produces a planetary nebula what will its approximate luminosity be?
10 to the power of four solar units
4. When the sun becomes a white dwarf with a surface temperature similar to its current surface temperature what will its luminosity be?
4,000 degrees kelvin

Page 359.

9. What will happen to Earth as the Sun changes in the future?
Runaway greenhouse effect when the carbon dioxide cycle no longer regulates the earth's climate. Oceans will boil away causing devastation for life on earth. Sun will expand to nearly the size of earth's orbit which means solar prominences possibly hitting earth's surface. If not destroyed, Earth will be a charred, eventually cold, rock.
13. Why can't iron be fused to release energy?
Iron cannot be fused to release energy because for elements heavier than iron, the mass per nuclear particle increases, so fusing two iron nuclei requires more energy than it produces.
19. Humanity will eventually have to find another planet to live on because one day the sun will blow up like a supernova
This does make sense
22. If you could look inside the sun today, you’d find that its core contains a much higher proportion of helium and a lower proportion of hydrogen than it did when the sun was born. This statement makes sense ... When the sun was born the percentages were about 94% hydrogen and 4%. Helium.

Chapter 14, p. 407, # 1, 7, 13, 15

1. n/a I have no illustrator
7. What are cosmic rays and where are they thought to have come from

Cosmic rays are immensely high-energy radiation, mainly originating outside the Solar System. They may produce showers of secondary particles that penetrate and impact the Earth's atmosphere and sometimes even reach the surface. Composed primarily of high-energy protons and atomic nuclei, they are of mysterious origin.

13. Briefly describe the characteristics that distinguish the galaxy's disk population of stars from its spheroidal population of stars.

15. What is Sgr A*? What evidence suggests it contains a massive black hole
Contains mass of 3 to 4 million solar masses within a tiny region of space. Has faint X-ray emisson= puzzling= matter falls into it in big chunks, not smooth. Why do we think that Sgr A* is a super-massive black hole? Proper motions of stars within 1 arcsecond show that these stars are moving extremely fast, some over 1000 km/s. Indeed, nearly complete stellar orbits have now been measured, clearly indicating a "dark" gravitational mass of nearly 4 million solar masses is contained within a region of about 100 AU centered on the position of Sgr A*.
Chapter 15, p. 441, # 1, 2, 13, 14, 20,

1. What are the three major types of galaxies, and how do their appearances differ?
Spiral galaxies-flat white disks with yellow bulge at their centers with spiral arms. Have bulge, disk, and halo (disk component and spheroidal component, two arms of tuning fork diagram). EX: Milky Way Galaxy
Elliptical galaxies-Red, round and elongated (football). Has bulge and halo (spheroidal galaxy, handle of the tuning fork diagram) EX: NGC 2728
Irregular galaxies-No particular shape and small (placed b/w spirals and barred spirals) EX: large and magellanic clouds which are in the halo part of the milky way galaxy
2. Describe the differences b/w normal spiral galaxies, barred spiral galaxies, and lenticular galaxies.
Spiral- has disk and the spheroidal components with the spiral arms elongated outwards
Barred spiral galaxies- appear to have straight bar with spiral arms elongated outwards
Lenticular galaxies- galaxies that have the disk and spheroid components but dont have sprial arms
13. What do we mean by a cosmological redshift? How does our interpretation of a distant galaxy's redshift differ if we think of it as a cosmological redshift rather than Doppler shift?
The expansion of the universe as the photons in the universe, are stretched shifting them to longer redder wavelengths (cosmo redshift).
We interpret the Doppler's redshift as it is caused by the speed the galaxy with which the galaxy is moving. If we interpret as cosmo redshift, we use the fact that the universe is expanding with stretching all the photons present in it.
Distance begins to become ambiguous when the galaxy is far away, so it is preferable to interpret redshift of distant galaxies as the photon stretching cosmological redshift in the expansion of the universe.
14. What is the cosmological horizon, and what determines how far away it lies?
The horizon that which points the limits of the universe which we can see with telescopes. Radius of universe is used to determine the cosmological horizon which marks limit of the universe beyond which nothing is visible to us (marks limit of the observable universe-in time, not in the space). Current radius is 46 billion light years from Earth.
20. Briefly describe the discovery of quasars. Why can we learn more about quasars by studying nearby active galactic nuclei and radio galaxies?
Quasars are bright galactic centers are called active galactic nuclei, brightest active galactic nuclei are known as quasars. Marteen Schmidt was identifying cosmic sources for radio wave emission and found a blue star object that had strong emission lines at wavelength that did not correspond to known chemical elements (red shifted hydrogen emission lines). Calc speed>distance>apparent brightness>object had great luminosity>quasars.
Quasars are the center of extremely distant galaxies and often members of distant galaxy clusters (hard to study b/c far away). Active galactic nuclei are much closer (similar to quasars but less powerful) and easier to see the surrounding galaxies. Radio galaxies emit unusually strong radio waves (emission comes from pairs of huge radio lobes). Many quasars have jets and radio lobes like seen in radio galaxies
Chapter 16, p. 467, #1
Define dark matter and dark energy, and clearly distinguish between them. What types of observations have led scientists to propose the existence of each of these unseen influences?
Observations of gravitational effects on matter (gives little or no light-dark matter). Accelerating expansion of the Universe, counteracting effect of gravity-dark energy.

Chapter 17, p. 1, 2, 3, 25

1. What is antimatter? How were particle and antiparticle pairs created in the early universe? How were they destroyed?

Antimatter: molecules formed by atoms consisting of antiprotons, antineutrons, and positrons. Stable antimatter does not appear to exist in our universe.
Particle and antiparticle pairs were created by fusing a particle of matter and anti matter to make pairs. They annihilate each other.

2. Explain what we mean by the Big Bang theory?
Theory that universe began in a single moment from incredible hot, tiny , dense collection of matter and radiation. And how expansion and cooling of unimaginable mixture of particles and photons led to the creation of our stars and galaxies.
3. Big bang, Planck Era, Gut era, Electroweak era (Eras of the early universe), Particle era, Era of Nucleosynthesis, Era of Nuclei, Era of Atoms

Chapter 18, p. 530-531, visual skills check 1-6, 1, 4, 7, 14, 17, 18, 19, 23, 24, 25

1. order first time there is significant oxygen on earth first life on earth earliest plants living on earth impact causes extinction of dinosaurs
Earliest mammals earliest animals earliest humans

2. order
Hadean
Proterzoic
Paleozoic
Cretaceous

3. The quaternary period.
4. Around 500 million years
5. between 3.8 and 4 million years ago.
6. about 225 million years.
REVIEW:

1. Describe three recent developments in the study of life on earth that make life elsewhere seem more plausible.

We have learned that life arose quite early in earth’s history, suggesting that life might also form quickly on other worlds with the right conditions.

Lab experiments have shown that chemical constituents combine readily complex to organic molecules. These experiments suggest that life might have arisen naturally occurring chemistry.

We have discovered microscopic living organisms that could probably survive in conditions similar to those of other worlds in our solar system, suggesting tht necessities of life may be common.

4. Why is the theory of evolution so critical to our understanding of the history of life on earth, explain how evolution proceeds by natural selection.
The theory of evolution is the change in populations over time. It is the process by which modern organisms have descended from ancient organisms. Through natural selection many individuals of any species that posess certain traits gain advantage in reproduction.
7. Is it possible that life migrated to earth from elsewhere?
Yes it is possible, venus mars and earth have been interacting for billions of years, life could have been carried via meteorites between the planets.
14. What is SETI?
SETI is the search for extra terrestrial intelligence, listening for single of intelligence coming from other world etc. SETI may have a chance to succeed only if other advanced civilizations are broadcasting receivable signals.
17. The first human explorers on mars discover the ruins of an ancient civilization, including remnants of tall buildings and temples.
Science Fiction
18. The first human explorers on mars drill a hole into a martian volcano to collect a sample of soil from deep underground. Upon analysis of the soil they discover it hold living microbes resembling terrestrial bacteria but with different biochemistry.
Science Fiction
19. in 2040 a spacecraft lands on Europa and melts its way through the ice into the European ocean . It finds numerous strange living microbes along with a few larger organisms that feed on the microbes.
Science fiction, realistic scenario but not yet made possible.
23. In 2030 a brilliant teenager working in her garage builds a coal powered rocket that can travel half the speed of light
Fantasy, nothing travels at the speed of light
24. crew members of the matter anti matter spacecraft star Apollo which left the earth in the year 2165 returns to earth in the year 2450 looking only a few years older than when they left.
Science fiction, realistic scenario by mean of space travel but not yet made possible in present day.
25. A single great galactic civilization exists. It orginated on a single planet long ago but is now made up of beings from many different planets assimilated into the galactic culture.
Science Fiction, there could living beings on other worlds not known to our knowledge, the scenario Is realistic and not irrational.