Online reading assignment: runaway planets, jovian planets, and dwarf planets (oh my!) (SLO campus)

Astronomy 210, spring semester 2020
Cuesta College, San Luis Obispo, CA

Students have a weekly online reading assignment (hosted by SurveyMonkey.com), where they answer questions based on reading their textbook, material covered in previous lectures, opinion questions, and/or asking (anonymous) questions or making (anonymous) comments. Full credit is given for completing the online reading assignment before next week's lecture, regardless if whether their answers are correct/incorrect. Selected results/questions/comments are addressed by the instructor at the start of the following lecture.

The following questions were asked on reading textbook chapters and previewing presentations on runaway planets (Venus and Mars), jovian planets (Jupiter, Saturn, Uranus and Neptune), and the dwarf planets (and the International Astronomy Union classification scheme).


Selected/edited responses are given below.

Describe something you found interesting from the assigned textbook reading or presentation preview, and explain why this was personally interesting for you.

"The descriptions of other terrestrial planets, which makes it just more of a miracle that Earth is capable of hosting life, when others with just some things a bit wonky are inhospitable."

"How Venus is 95% of Earth's diameter but it's very different from Earth. It has volcanos, lava flows, and impact craters, in a deep hot atmosphere."

"I don't know why but I always looked at Venus and thought 'huh, she's kinda pretty.' I knew she was made of gas. But I didn't know she was hot enough to melt lead, smells bad and that the greenhouse effect is much worse there."

"I found it interesting that Venus had geological features (such as coronae) unique to anywhere else in the solar system. I had some curiosity about studying planets and the characteristics that make them unique (such as Uranus' reverse rotation). This information can help us compare our own planet with others and understand geologic activity elsewhere in the solar system."

"I found the ability to determine certain areas of a planet as new or old very fascinating. Being able to figure out which parts of the crust are fresh, or how long it's has been there is interesting to know. Also I really enjoyed the thick gravy skin analogy in describing hot spots."

"I liked learning about the surface features of Venus and Mars. I also like seeing the different things the other planets and Earth have in common. "

"I found learning about the greenhouse factors on Venus and Mars interesting because I have heard Earth's greenhouse effect discussed often but never considered other planets' greenhouse effects."

"Reading about the conditions of Mars was interesting to me. It's a lot less inhabitable sounding that it's been made to seem."

"I found the amount of water that is predicted to be on and within Mars interesting. Especially the early stages of Mars where there were large bodies of water."

"These were the most interesting points I read: (1) Venus is a hot lava volcano planet. (2) Liquid water on Mars can't exist because it would boil away instantly. (3) Jupiter has four large moons and at least 60 small moons. (4) Saturn's rings are ice. (5) Pluto has five moons."

"I found the part about water on Mars the most intriguing. the fact that there is still frozen water on the poles, as well as signs of liquid water on the surface, is really cool and makes me wonder what else we may have yet to find on Mars."

"I found it super-interesting that none of the jovian planets have a surface that you would be able to walk on, because they are hydrogen-rich planets and are have lots of water in both solid and liquid."

"I found it interesting that Saturn's rings are actually composed of ice particles. I never knew this before, so I found it interesting to actually be told what exactly it's composed of and why."

"One thing I found interesting was that when the sun warns the clouds, they tend to rise higher in the sky on Jupiter. However, Saturn doesn't receive as much sunlight so the color and clouds are lower ant faint."

"I found Jupiter and its atmosphere extremely interesting, I just think that it is crazy that Jupiter is mostly composed of liquid metallic hydrogen."

"How Uranus has the coldest interior temperature of the jovian planets."

"I found the information about the planets interesting. I'm especially interested in planetary classification and excited to dive deeper into it."

"I found the extreme differences between the planets to be very interesting. I remember learning a lot 'about' the planets in grade school. By a lot, I mean we learned how many there are (were, RIP Pluto) and memorized mnemonic devices for their order. However, I don't recall focusing much on their matter or other specifics or most importantly, what these mean for their history. I enjoyed getting to know more about the planets and what is important about this hints to how they came to be."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.

"Nothing was specifically confusing, but I can feel that I will have a hard time remembering the different aspects of greenhouse gases and how they relate to planets. (Though the turkey/Cornish hen image does help a ton!)"

"I think it's kinda weird and confusing how the oceans dried up on the other planets and how we know they were there at one point. Why did they disappear or evaporate?"

"I was confused about how Mars and Venus compared to Earth in terms of geologic activity and core features. I felt pretty clear about how each planet retained heat but was unsure about these two particular things."

"I had trouble understanding the 'runaway atmospheres.' I can't seem to grasp how each planets greenhouse cycle was broken, or how the breaking of each cycle began in the first place. The order of events in which the cycle proved to be broken was difficult to understand."

"How the greenhouse effect works. I was trying to figure out how mass and other things that affect it."

"I found it confusing that the textbook said Mars had no water, but then proceeded to say that the water is found through the permafrost and in the polar caps. It was very confusing, because it felt like they kept contradicting themselves."

"How if there is water on Mars it boils away because of the low air pressure, but the only water found on Mars is like permafrost."

"I didn't completely understand the 'Cooper Cooler® effect.' I found this confusing because I didn't fully understand what the it was used to explain."

"I would like to understand jovian planets better and what determined a planet to be a ice or gas giant, and greenhouse factors for the terrestrial planets."

"The different clouds and gas situations with the jovian planets. I think I just need better visuals. "

"Dwarf planets and how are they formed."

"It wasn't quite clear to me what makes something a planet versus a dwarf planet."

"I don't understand why scientists reclassified Pluto. What new criteria did they add that suddenly knocked Pluto down to being a dwarf planet?"

"Trying to figure out whether or not Pluto is a planet was confusing. there are a few things that define a planet and Pluto seems to fit so but not all."

"There wasn't much to be confused about because it was mainly just describing the planets."

Identify the relative amounts of these characteristics for Venus, compared to Earth. (Only correct responses shown.)

Interior core heat, today: about the same as Earth [26%]
Geologic activity, today: less than Earth [47%]
Volcanic outgassing, up until now: about the same as Earth [33%]
Heat from the sun: more than Earth [86%]
Amount of atmosphere, today: more than Earth [62%]

Identify the relative amounts of these characteristics for Mars, compared to Earth. (Only correct responses shown.)

Interior core heat, today: less than Earth [76%]
Geologic activity, today: less than Earth [68%]
Volcanic outgassing, up until now: less than Earth [62%]
Heat from the sun: less than Earth [85%]
Amount of atmosphere, today: less than Earth [85%]

Which jovian planet has the coolest interior temperatures?

Jupiter (most massive).	* [1]
Saturn (most prominent rings).	[0]
Uranus (least active weather patterns).	************** [14]
Neptune (farthest from the sun).	************* [13]
(Unsure/guessing/lost/help!)	****** [6]

I believe Pluto should be a planet.

Strongly disagree.	* [1]
Disagree.	************ [12]
Neutral.	************ [12]
Agree.	******** [8]
Strongly Agree.	* [1]

Briefly explain your answer to the previous question (whether Pluto should be a planet).

"I am not too sure what to think!"

"We should continue studying Pluto."

"It was once a planet and has the qualities of a dwarf planet so I think it should still be considered one."

"Although my childhood consisted of identifying Pluto as a planet, there are much smarter people than me, that have established the necessary guidelines for being a planet. They have determined Pluto does not qualify, and I have no grounds to stand against their expertise."

"I disagree that Pluto should be a planet because it's out of the orbiting rings."

"It should be considered a planet due to it still being in the solar system and that it was one of the first planets they spotted."

"Growing up, I was always told that Pluto was a planet. So it is a little confusing why the scientists reclassified it."

"Just always remember being taught the solar system when I was younger and learning all the planets and now being taught that Pluto isn't a planet just brings out the little kid in me wanting it to be classified as a planet again."

"I am a little on the fence on this one, but since it is not similar to the jovian or terrestrial planets, and there is other icy bodies orbiting beyond Neptune, some more massive then Pluto, it seems fit that it would not be considered a planet unless other ones were also."

"Honestly I can not say I would need more peoples point of view on whether it is a planet or not."

"I am not sure on the difference between a planet and at what point its a dwarf, so I cant say for sure."

"I believe scientifically that Pluto is a dwarf planet but it will always be a planet in my heart."

"I hate to say it this way, but I guess I just don't really care if it's considered a planet or not--labels, ya know?"

"I agree because it has an orbit, has moons, and has different gasses on its surface. Just because it's tiny and a little farther out there, shouldn't discard it from being a planet. It's hard to make a decision on an issue that was decided on by scientists much more advanced that I will ever be, and overturned as well."

"They can't make Pluto a planet and then take the title away. Plus it's still a dwarf planet."

"It is one of many objects in the outer belt of the solar system, so if Pluto should be considered a planet than so should the others."

"I don't believe that it qualifies as a planet because of the fact that it is so small, it doesn't even qualify as a jovian planet, and its orbit can bring it closer to the sun than Neptune at times. That doesn't seem like any type of orbit of a planet in our solar system, therefore I don't think ti should qualify as one. Even if it has its own moons."

"Too small to be a planet and doesn't have too many characteristics of a planet."

"I don't really care either way."

"No Pluto is too small and lacks gravitas."

"It is a dwarf planet, not big enough to be move stuff, but large enough to be a something. It is not big enough or diverse enough to be able to say that it is a planet."

"Personally I don't mind Pluto can be who he wants to be but scientifically speaking he can't really be classified as a planet."

"I feel that since Pluto is somewhat planet like but seems to be an outlier and differ in some aspects that it should remain as it is. Why change it after all this time if it is fine the way it is. They clearly made that decision for a reason."

"Pluto fits the definition planet: a celestial body moving in an elliptical orbit around a star."

"While Pluto does have its own moon, there are other planets of similar mass nearby. For instance, there are a series of other planet-like objects orbiting in the outer edge of solar system (Eres, Ceres, Makemake for example). This suggests that Pluto does not meet the third IAU criteria, meaning it cannot expel neighboring dwarf planets/objects."

"I think size should matter to determiner weather something is a planet or not and Pluto has gotten to small I think to be called a planet."

"I honestly don't know enough to know how to answer."

"Pluto doesn't fall under the category of being a terrestrial planet nor a Jovian planet, therefore it is it's own identity which is considered a dwarf planet."

"Pluto should be a planet for several reasons. First of all it has a large enough gravitational pull to be described as a planet. Second of all, just because it does not fit into the categories of jovian or terrestrial does not mean that it is not a planet, it is a different type of planet. Third of all, Pluto is super cool and it is messed up that we gave Pluto the title of planet and then revoked the title."

"If Pluto doesn't fit all the IAU rules and classes then it shouldn't be called a planet."

"The IAU has been studying these things for some time. If we don't stick to some kind of set rules for naming things, we'll have too many planets."

"I'm not too invested into whether or not Pluto should be a planet."

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.

"Can you further explain what happened to Mars' water, because I am still confused."

"Something I found confusing is that on Mars water would immediately boil into vapor, but there are polar caps that are frozen? That confuses me because wouldn't the polar caps just vaporize, too?" (Liquid water would immediately boil into vapor, but solid chunks of ice could survive, especially underground (permafrost), or at the much colder polar caps (which are so cold that carbon dioxide snows as dry ice.)

"Have you ever watched the show Psych? One of the main character's pick up line was, 'You heard about Pluto? That's messed up, right?'"

"I have read that Pluto is a part of the Kuiper belt, is that true?" (Yes, Pluto is just one of an estimated 100,000 other comparable-sized dwarf planets in the Kuiper Belt.)

"Is Pluto a planet or not?"

"Do you think Pluto should be a planet?" (Eh, no. Otherwise then everybody else in the Kuiper belt would get to be planets, too.)

"Would you ever purchase a star and name it after something? (Like your wife lol.)" (No, because I think that company is honestly pretty shady, and not really the "official" registry for star names, as well.)

"Why does Haumea look like an egg?" (It is hypothesized that its rapid rotation rate stretched and distorted its shape as it solidified.)

"This lesson seems easy at first but kinda have to remember a lot."

"Are we going to eventually learn the math for what we have learned/are learning?"

"There are some claims that were made about NASA not actually making it to the moon, are these some things we can consider or that it's just conspiracy theory?" (Buzz Aldrin, the second person to set foot on the moon, was so annoyed by a conspiracy theorist pestering him to admit the moon landings were fake that he punched him in the face. #justsaying)

Online reading assignment: runaway planets, jovian planets, and dwarf planets (oh my!) (NC campus)

Astronomy 210, spring semester 2020
Cuesta College, San Luis Obispo, CA

Students have a weekly online reading assignment (hosted by SurveyMonkey.com), where they answer questions based on reading their textbook, material covered in previous lectures, opinion questions, and/or asking (anonymous) questions or making (anonymous) comments. Full credit is given for completing the online reading assignment before next week's lecture, regardless if whether their answers are correct/incorrect. Selected results/questions/comments are addressed by the instructor at the start of the following lecture.

The following questions were asked on reading textbook chapters and previewing presentations on runaway planets (Venus and Mars), jovian planets (Jupiter, Saturn, Uranus and Neptune), and the dwarf planets (and the International Astronomy Union classification scheme).


Selected/edited responses are given below.

Describe something you found interesting from the assigned textbook reading or presentation preview, and explain why this was personally interesting for you.

"I found Earth's active crust very interesting. I found this interesting to try to picture the surface of Earth just floating on the mantle."

"'Runaway greenhouse.' I thought this concept was interesting because I found the greenhouse effect interesting to begin with, but to find out that this is the reason why Venus lost its oceans and habitable atmosphere."

"That Venus could have possibly had oceans like Earth."

"The fact that Venus could have been like Earth. A long time ago it was close to how Earth is weatherwise but then with all the volcanoes exploding and putting CO₂ into the air, it started rapidly being a runaway effect and now is the planet as we know it. I just think it's interesting how in the future something like this could happen to Earth if we let it get that bad."

"Venus' atmosphere is *96%* CO₂--that's insane, I knew it was primarily greenhouse gases but I didn't know it was that much CO₂."

"I found it interesting that we only have a few pictures of the surface of Venus. This interests me because I am attracted to the magic in the universe, and I find that for me, the most magical things are the ones we don't know."

"The maps of Venus and Mars were interesting because it showed basically what their surfaces were and what they're made of."

"The atmosphere of Mars is thinner than Earth's. It is 1% as dense as Earth."

"I found it interesting how Mars has little water, but it is composed of frozen ice water that is covered with carbon dioxide."

"That no liquid water can be present on Mars to this day due to the low atmospheric pressure."

"Mars has small moons, which Mercury and Venus don't. The moons are captured asteroids. I knew Mars had moons but, I didn't know those moons where captured asteroids."

"The term 'jovian planets.' "

"I found gas giants to be the most interesting. Just because it's cool to see different compositions of planets."

"I thought that reading about Jupiter's interior and its atmosphere. I had no idea that Jupiter is only 1.3 times denser than water, which is super interesting and something I had no idea about. Learning that liquid metallic hydrogen makes up Jupiter's interior was a fun fact. Jupiter's force is 10 times stronger than Earth’s force which I usually just learned about Earth and its interior so it's interesting to learn more about other planet and how different it is from Earth."

"What I found the most interesting about the readings were the jovian planets and the dwarf planet Pluto. I found this interesting because I feel that we know more about the inner and terrestrial planets because since they are closer to Earth, they are easier to study and easier to observe. Since Jovian planets are further away, they may be more difficult to study and observe, and we may not know as much about them and their properties. They seem more foreign, which makes them more interesting."

"The difference between a planet and a dwarf planet. It all depends on their size."

"The reasons Pluto isn't a planet anymore. When I was young, I thought it was about size, not gravitational force."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.

"The greenhouse effect is still a little bit confusing to me, I understand the basics, but could use a small review."

"Remember what planet is which and its characteristics are confusing."

"Did Venus' greenhouse cycle collapse relatively recently or was it millions of years ago, and how long is it estimated to have taken for its oceans to have evaporated? That's what I don't understand, do we just not have any idea since it's so hard to get a probe there and keep it working."

"The runaway greenhouse effect on Venus wasn't very detailed and I need further information to understand."

"How/where did the preexisting water on Mars go?"

"Shield volcanos. I just don't understand how they are formed."

"How the jovian planets gained so much mass in the first place. I believe it had to do with how much gas was around when it formed and gravity took over the rest but I'm not sure."

"Jovian planets. Just completely lost."

"Which is the coldest jovian planet. I could not find where it told us."

"I didn't quite understand the reasoning for why Uranus cooled faster than Neptune and what it’s axis has to do with it. I understand the Cooper Cooler® effect but don't quite understand how it applies to Uranus."

"How can a planet even get rings?"

"Something that I still don't understand fully is why the IAU considered Pluto not a planet in the solar system."

Identify the relative amounts of these characteristics for Venus, compared to Earth. (Only correct responses shown.)

Interior core heat, today: about the same as Earth [29%]
Geologic activity, today: less than Earth [64%]
Volcanic outgassing, up until now: about the same as Earth [36%]
Heat from the sun: more than Earth [82%]
Amount of atmosphere, today: more than Earth [61%]

Identify the relative amounts of these characteristics for Mars, compared to Earth. (Only correct responses shown.)

Interior core heat, today: less than Earth [61%]
Geologic activity, today: less than Earth [86%]
Volcanic outgassing, up until now: less than Earth [43%]
Heat from the sun: less than Earth [64%]
Amount of atmosphere, today: less than Earth [82%]

Which jovian planet has the coolest interior temperatures?

Jupiter (most massive).	[0]
Saturn (most prominent rings).	** [2]
Uranus (least active weather patterns).	********** [10]
Neptune (farthest from the sun).	************* [13]
(Unsure/guessing/lost/help!)	*** [3]

I believe Pluto should be a planet.

Strongly disagree.	*** [3]
Disagree.	******* [7]
Neutral.	********** [10]
Agree.	***** [5]
Strongly Agree.	*** [3]

Briefly explain your answer to the previous question (whether Pluto should be a planet).

"Pluto should be considered a planet because it had be considered a planet before why not know."

"I disagree that Pluto should be a planet because: it doesn't meet the IAU's criteria for for planet status, and planetology shows that Pluto isn't related to jovian nor terrestrial planets."

"Why would they make it a planet and then just say, 'Hey let's not consider Pluto a planet anymore?'"

"The status of Pluto shouldn't matter but rather what information we can learn from it."

"It's still pretty big, doesn't orbit another planet, and it has moons."

"I believe it should be a planet because its orbit is severe? wasn't able to read to this section The dwarf planet and others like it are not big enough to clear their orbital path."

"I feel that even though Pluto may not be big enough to be a planet it should still be classified as one since I mean it does have five moons."

"Because Pluto is in our solar system, it rotates and revolves. Plus it would be a little awkward explaining to someone saying, yeah that planet is in our solar system but we just ignore it. Give it the benefits of being a hard working planet even if it is small and slow."

"In the book one of the reasons Pluto is not a planet is because it's not large enough to dominate and gravitationally clear its orbital region."

"By the same classification, the the moon and Mars are both dwarf planets."

"Pluto is not related to the jovian planets or terrestrial planets and is isn't really special in a way. I do not believe that Pluto should be a planet."

"I am not really sure if it should be a planet or not. Because what are the characteristics to define a planet. if we decided to call a planet at one point why did we go back on it?"

"I grew up thinking Pluto was a planet."

"I never really was educated on why Pluto wasn’t a planet anymore, I was just told, but when the book mentioned that it is jovian and other reasons then it makes sense. However at the same time, they made Pluto a planet originally which means they would have evidence which would justify it. This is why I don't really have an opinion."

"I believe Pluto should be considered as a planet because just like any other planet it has an orbit around the sun and even gets closer to the sun in orbit than Neptune at times. Also like a planet Pluto has moons that orbits itself like any other planet would have as a charchteristic."

"I believe it shouldn't because its too small and too far out of our solar system the convention that produced the definition excluding pluto as a planet had a small attendance and their definition that excludes Pluto from being a regular planet, that being it hasn't 'cleared its neighborhood,' excludes Earth, Mars, Jupiter, and Neptune as they share their orbits with asteroids. less than 5% of the astronomical community voted for the change, which hardly represents the total opinion."

"I think if NASA has one stated that it's too small to be considered and it can not make its own orbital path clear then we can't call it a planet like the others."

"If I am correct I think I remember hearing many disputes about whether or not Pluto should be considered a planet but I think it is a dwarf planet. I put neutral due to not knowing the reasons for why it should or should not be a planet."

"Scientists have made Pluto no longer a planet and I trust their judgment."

"From my point of view, I decided that Pluto shouldn't be planet because Pluto is just a chunk of ice floating around the Kuiper belt."

"I picked neutral on whether if Pluto should or shouldn't be a planet because I don't think that I know enough about Pluto to say yes or no."

"With the information I have, I'm neutral because it sounds like it has an orbit since it has 5 moons, but at the same time I'm wondering if the moons are just in the same orbit Pluto is trapped and not actually trapped in Pluto's individual orbit."

"I am not quite sure of Pluto should be or should not be considered a planet, but I may lean towards that it isn't a planet, since it is not classified as terrestrial or jovian and it does not have the normal properties of a planet."

"A planet must be large enough to have the largest gravity in its own vicinity, and Pluto doesn't."

"Pluto is really close to a lot of other dwarf planets."

"This statement is not something I can answer. Pluto is a planet. A dwarf planet. So whether I believe it should be or not is irrelevant."

"Pluto has moons so it should be considered a planet."

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.

"Venus and Mars are so different, why? Is it just due to the different distances from the sun?" (Also their size as well.)

"Can you go over the planets and what considers something to be a planet?"

"Do you believe that Pluto deserves the recognition to be considered as a planet?" (Eh, not really. There are lots of other planets that were historically demoted as well, notably Ceres.)

"What would the modern reaction be if another planet was classified as no longer a planet or if one that wasn't previously was made into a planet?"

"I think I need a tutor for astronomy because the concepts just don't click with me." (There is an astronomy tutor available on SLO campus on Mondays and Wednesdays.)

Online reading assignment: atmosphere problems, Earth, the moon, Mercury (SLO campus)

Astronomy 210, spring semester 2020
Cuesta College, San Luis Obispo, CA

Students have a weekly online reading assignment (hosted by SurveyMonkey.com), where they answer questions based on reading their textbook, material covered in previous lectures, opinion questions, and/or asking (anonymous) questions or making (anonymous) comments. Full credit is given for completing the online reading assignment before next week's lecture, regardless if whether their answers are correct/incorrect. Selected results/questions/comments are addressed by the instructor at the start of the following lecture.

The following questions were asked on reading textbook chapters and previewing presentations on problems caused by the atmosphere for telescope observing, Earth, and the impacted worlds: the moon, and Mercury.

Selected/edited responses are given below.

Describe something you found interesting from the assigned textbook reading or presentation preview, and explain why this was personally interesting for you.

"That light waves can be affected by our atmosphere. I just found it interesting because it was something that I never considered."

"How light pollution can affect so many things in our environment, such as animals."

"That light pollution interferes with the view of the stars/planets. People would then need go to hilltops far away away from the light pollution just to look at the clear stars and planets."

"I found light pollution very interesting and did not think it was a very big problem until I read into it some more."

"Something I found interesting was that if you were to go to a rural town with not very many lights you could see a faint Milky Way. I found that interesting because we do not get that many chances to see it if you do not leave your hometown."

"Comparing the atmosphere to rippling water was a good analogy. I found this part interesting because I knew that the atmosphere made it more difficult to view view things using a telescope, but this comparison made it easier to understand why."

"I found the comparison between sitting under a pool of water and looking up to sitting under a 'pool' of air really interesting. I never thought about how movement in the sky, such as turbulence, could create such a problem for astronomers or anyone interested in the views of the sky."

"I found learning about how atmospheric turbulence and opacity affect our ability to use telescopes and the ways we combat those effects interesting. I never understood why it was better to have telescopes at a higher altitude and now I do."

"I found the readings about different ways that astronomers have to go about collecting different types of electromagnetic radiation. I found this interesting because it forces them to find new and interesting ways to collect data, which leads to a deeper understanding of our known universe."

"I thought that it was very interesting that telescopes in space can be the size of a bus. This is crazy to me how they can be that and still be be able to function in space."

"Airborne and space telescopes (airplanes, balloons, rockets and satellites), because it is such an interesting perspective to think about."

"I liked reading about all the different atmospheres on the different planets and I liked how it got into global warming. I was also interested by the stages that earth has gone through to and how we'll basically always be in stage three because Earth's surface is constantly changing."

"The greenhouse effect of how an atmosphere traps heat and raises the temperature of a planetary surface. It's crazy how the atmosphere has such an effect on planets--without it, Earth would be a lot different."

"The large impact hypothesis, stating the bulk of two objects will combine to form Earth (and the moon), with most of their cores and the surrounding crust melting, then coalescing."

"I was interested particularly in the geology comparing the planet Mercury to our own moon. Both involved the formation of craters followed by partial filling of lava. I found it fascinating that both bodies were strikingly similar and figured that this could help us learn more about the formation of other planets."

"When learning about the history of Earth's moon, I really enjoyed reading about the magma ocean, it just sounds super awesome to picture."

"I thought the different sizes of the moon's core versus Mercury's core was interesting because you would expect them to remotely similar but are different and you can determine this by the gravitational pull."

"I really liked looking at the pictures of the moon's and Mercury's surfaces. It is cool looking at the ridges and craters shown in the pictures."

"I think it's increasingly interesting how much we think we know about other planets that is primarily based on extrapolation. All of this could change as soon as new evidence presents itself."

"Super-hectic weekend and wasn't able to get to the reading but I will before class!"

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.

"I do not understand the electromagnetic spectrum graph or how to use it."

"I did not quite get what the difference between radio astronomy and light astronomy was. I wanted to know, but was just lost by the name drop."

"I don't understand how atmospheric turbulence occurs."

"I'm still catching up on the history stuff, I'm really bad at remembering names and related numbers and just putting it all together in the right way."

"The greenhouse effect."

"How carbon dioxide enters and leaves the atmosphere and everything about it, mainly confusing because I thought I already had an idea and now I am jumbled up."

"I was confused about how an asteroid wouldn't be able to break the moon's structure or crack it, it would only leave a crater."

"Something I found confusing was trying to determine which craters were oldest to youngest. Personally because when I was reading the information I just could not retain it."

"That the four inner planets were composed of rock when the outer planets are not."

"The atmosphere on Venus. Why is it so cloudy and thicker than Earth's? It's confusing for me because I thought all the planets had the same amount of atmosphere."

A large modern optical telescope in outer space would have images with better __________ than a comparable ground-based telescope.

brightness.	******** [8]
resolution.	************************ [24]
magnification.	* [1]
(Unsure/guessing/lost/help!)	*** [3]

Stars to appear to "twinkle" in the night sky because of...

"The stars twinkle in the night sky because of the effects of our atmosphere. When starlight enters our atmosphere it is affected by winds in the atmosphere and by areas with different temperatures and densities. This causes the light from the star to twinkle when seen from the ground."

"Movement within the atmosphere causing the images of the stars to move and blur."

"Stars appear to twinkle in the night sky because of the effects of our atmosphere. When the light from the stars enter our atmosphere, it experiences turbulence. This causes the stars to look like they 'twinkle.'"

"Living in at the bottom of an 'ocean of air,' turbulence disturbs the air in the atmosphere, making our view disrupted."

"The way our atmosphere moves and shakes."

"I'm not sure, I don't remember this part of the reading."

"Unsure."

Identify how carbon dioxide enters and how it is taken out of Earth's atmosphere.
(Only correct responses shown.)

Enters atmosphere from: volcanoes [44%]
Taken out of atmosphere by: oceans [57%]

Identify the oldest (longest ago) to the youngest (most recent) features on the moon.
(Only correct responses shown.)

Craters partially filled in with flat lava plains: oldest (formed longest ago) [31%]
Flat lava plains: middle [22%]
Craters on top of flat lava plains: youngest (formed most recently) [53%]

Identify the oldest (longest ago) to the youngest (most recent) features on Mercury.
(Only correct responses shown.)

Large crater basins: oldest (formed longest ago) [39%]
Lava-filled lowlands: middle [61%]
Long curving ridges: youngest (formed most recently) [58%]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.

"I was unsure about why the segmented mirrors might be beneficial. The textbook said that the thin mirrors weigh less and cool faster?" (Yes, saving weight is important when there are so many mirror segments in a large telescope, and having the mirrors be able to cool down (or warm up) quickly is good, because any temperature differences will make a "mirage" effect from thermal air currents around the mirror segments.)

"I found understanding the order that the features formed on the moon and mercury difficult to grasp, the moon a little more so than Mercury. To me, neither the textbook or online presentations presented a clear order and explanation of how we can tell which order they came in."

"I was confused about the order that things occurred on moon because I searched pretty hard and couldn't really find the definitive answer." (We'll be sure to cover this in class this week.)

"What is the significance of knowing the surface features of the moon? Those are just the way it formed, but I would want to know why it's so important to study the moon." (We brought back an abundance of samples from different parts of the moon for thorough laboratory analysis, so we have a very good idea of how the moon formed. Since we do not have samples from other planets (yet) that we can analyze back here on Earth, then the best way to understand those outer planets is to compare their similar/different features compared to the moon's features.)

"I thought the large impact theory in reference to the moon and Earth colliding would have ruined the round structure of both, but I assume over time the gravitational pull at the core would reshape the round sphere?" (Yes, the impact would melt/vaporize both, but as that material cooled gravity would bring everything back together similar to how they first formed by themselves, but now they'll form side-by-side, with the current moon made mostly of the vaporized outer layers of both.)

"I don't totally understand how the large impact theory for the moon's formation is supported when there's contradictory evidence." (Well, it is the best supported and also least contradicted theory given the evidence available.)

Online reading assignment: atmosphere problems, Earth, the moon, Mercury (NC campus)

Astronomy 210, spring semester 2020
Cuesta College, San Luis Obispo, CA

Students have a weekly online reading assignment (hosted by SurveyMonkey.com), where they answer questions based on reading their textbook, material covered in previous lectures, opinion questions, and/or asking (anonymous) questions or making (anonymous) comments. Full credit is given for completing the online reading assignment before next week's lecture, regardless if whether their answers are correct/incorrect. Selected results/questions/comments are addressed by the instructor at the start of the following lecture.

The following questions were asked on reading textbook chapters and previewing presentations on problems caused by the atmosphere for telescope observing, Earth, and the impacted worlds: the moon, and Mercury.

Selected/edited responses are given below.

Describe something you found interesting from the assigned textbook reading or presentation preview, and explain why this was personally interesting for you.

"It's so cool to think about infrared light with longer wavelengths than visible versus ultraviolet with shorter wavelengths than visible light."

"How in a telescope's tube there can be a mirror at the back and the light can bounce back and forth inside the tube and project the image to the eyepiece. To be honest I found it interesting just as to the fact it's sort of simple, but also complex at the same time."

"I found that the "Keck in Motion" video was the interesting part for me because I personally thought it was cool on how they basically work together to find stuff out with the stars and how they move."

"I thought that light pollution was interesting. I was always wondering why telescopes are in the middle of nowhere, but I never looked into why they are so far away from civilization. The reason being light pollution makes complete sense and it makes me want to go to the middle of the desert somewhere at night and observe all the stars that I can't see in the city because of light pollution."

"After reading the textbook, I thought learning about light pollution was interesting because some places have more light pollution like big cities. This makes sense to me because I feel like people who live in the country enjoy looking up at the sky and soaking in its beauty. People who live in the cities might think the sky is pretty but may not think it's as pretty as people who live in areas with less light pollution because they are able to see more."

"I liked reading about sidereal tracking. I never thought about how telescopes would need to move continuously to continue to look at a certain point in space."

"What I found most interesting was the explanation for why stars appear to 'twinkle,' because stars don't actually twinkle but due to turbulence in Earth's atmosphere."

"It was very interesting to hear about different places where telescopes are placed."

"That the planets and the sun both start from a nebula."

"That we are capable of finding data on the formations, compositions, and histories of other planets despite there not being any humans that set foot on any of them."

"That the ocean absorbs the CO₂ in the atmosphere and filters it down to be trapped in sedimentary rocks. You only hear that plants use CO₂ in photosynthesis but never that the ocean could use it to make rocks. I found that really interesting."

"I did not know how hot Earth's core is compared to other terrestrial planet cores in our solar system."

"I thought the geological structures of Mercury being so similar to those of the moon to be very interesting."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.

"The big interferometer in the presentation slides, I was just confused in its entirety and how it works."

"The textbook's explanation of how carbon dioxide is removed by oceans."

"The creation of Earth's secondary atmosphere, because of the steps it took to create it--I wasn't familiar with carbon dioxide being soluble in water which helped remove CO₂ from the atmosphere."

"The history of the planets seemed to confuse me more than most of the reading. It just seemed like a blob of information to me and it was really hard to try to remember which fact was relative to which planet."

"I was confused on the features for the moon, the reading wasn't very specific."

"I still don't completely understand which craters are older or younger when it comes to the moon and Mercury. It's just not making sense to me."

"The large impact hypothesis for the moon's origin."

A large modern optical telescope in outer space would have images with better __________ than a comparable ground-based telescope.

brightness.	******** [8]
resolution.	************ [12]
magnification.	**** [4]
(Unsure/guessing/lost/help!)	*** [3]

Stars to appear to "twinkle" in the night sky because of...

"The twinkles are caused by turbulence in Earth's atmosphere. A star near the horizon will twinkle more than a star overhead."

"The light from the star travels through our atmosphere and by the time the light gets to earth its path will have bounced around a bit."

"The stars twinkle in the night sky because of the effects of our atmosphere. When starlight enters our atmosphere it is affected by winds in the atmosphere and by areas with different temperatures and densities."

"The way our atmosphere is."

Identify how carbon dioxide enters and how it is taken out of Earth's atmosphere.
(Only correct responses shown.)

Enters atmosphere from: volcanoes [48%]
Taken out of atmosphere by: oceans [52%]

Identify the oldest (longest ago) to the youngest (most recent) features on the moon.
(Only correct responses shown.)

Craters partially filled in with flat lava plains: oldest (formed longest ago) [37%]
Flat lava plains: middle [26%]
Craters on top of flat lava plains: youngest (formed most recently) [44%]

Identify the oldest (longest ago) to the youngest (most recent) features on Mercury.
(Only correct responses shown.)

Large crater basins: oldest (formed longest ago) [56%]
Lava-filled lowlands: middle [41%]
Long curving ridges: youngest (formed most recently) [56%]

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.

"Telescopes are pretty rad."

"How did science first figure out stars twinkle because of our atmosphere?" (The amount of twinkling is noticeably related to how windy it is. Less wind = less twinkling.)

"After doing the reading, what struck me the most was how there's atmospheric turbulence. The presentation talks how to solve this problem by placing the telescope as high as possible, where the thin air is. My question how do they know where the thin air is?" (Basically the higher up in elevation you are, the thinner the air--if you've driven or hiked up a high enough mountain, you may be literally "out of breath" because there is less oxygen up there for your lungs to take in. Also, yes, there would be less twinkling because there is less atmosphere up there.)

"Can a core of a planet reach the same intense heat of the sun?" (No. While Earth's core is pretty hot, the core of the sun is hella hot.)

"I'm completely lost on memorizing the terrain and the order it comes in, is there any shortcuts to remembering?"

"How can you tell which crater is younger and older and in the middle? Would smooth areas be considered youngest because it looks seemingly untouched since the planet formed?" (We'll go into further detail on this in class.)

"Can the moon die?" (It's already dead.)

"In the readings it is said that a large-scale collision may not have been responsible for Mercury's larger than expected iron core. It then just moves to the next stage of Mercury's expected history. Were no other theories developed on the planet's creation?" (There are many theories for Mercury's formation, but until a probe can land on its surface and analyze its rocks, then there really isn't much evidence to go on right now, and the limited evidence we have from looking at its surface from above is somewhat contradictory.)

"What's the oldest planet in our solar system?" (They're all the same age, in that they all formed at the same time as the sun from the same nebula. However, their surfaces will be different ages, because we think of rocks as "old" or "new" depending on how long it's been since they first hardened from being molten lava.)

"Will we have any opportunities for extra-credit? And when?" (Yes, typically in class just before/after each midterm, which is when most of you really need some extra-credit points.)

Online reading assignment: runaway planets, jovian planets, and dwarf planets (oh my!) (SLO campus)

Astronomy 210, fall semester 2019
Cuesta College, San Luis Obispo, CA

Students have a weekly online reading assignment (hosted by SurveyMonkey.com), where they answer questions based on reading their textbook, material covered in previous lectures, opinion questions, and/or asking (anonymous) questions or making (anonymous) comments. Full credit is given for completing the online reading assignment before next week's lecture, regardless if whether their answers are correct/incorrect. Selected results/questions/comments are addressed by the instructor at the start of the following lecture.

The following questions were asked on reading textbook chapters and previewing presentations on runaway planets (Venus and Mars), jovian planets (Jupiter, Saturn, Uranus and Neptune), and the dwarf planets (and the International Astronomy Union classification scheme).


Selected/edited responses are given below.

Describe something you found interesting from the assigned textbook reading or presentation preview, and explain why this was personally interesting for you.

"I thought the reasons for all the differences between the planets are really interesting. Like a planet's distance from the sun, how big it is, its atmospheric composition, it's core temperature, and how geologically active it is."

"Learning about the greenhouse cycle is very interesting for me. Larger planets putting out more greenhouse gas while smaller planets release less makes sense because of the mass of the planet and capacity to outgas. Also that because the strength of gravity on larger planets the greenhouse gases stay together is quite interesting."

"How important mass in relation to a planet's atmosphere and core heat is."

"That there is such a thing as 'frustrated volcanos' on Venus. Perfect GIF animation example btw..."

"I thought it was cool how Mars used to have oceans on its surface. This interests me because the astronomers were able to figure that out."

"The fact that there is hidden water on Mars! Maybe someday astronauts will find evidence that proves the planet was once hospitable."

"I enjoyed re-learning key aspects and characteristics of the planets and finding out new information about them that I hadn't known before."

"The 'bad' greenhouse effect was interesting, I never really knew before that too much could be bad in something like that."

"I find the runaway greenhouse effects of Venus and Mars very interesting. To me, Venus is especially interesting because it seems like it's the worst case scenario apocalyptic wasteland planet. In short, it's 'metal.' Very cool."

"How Jupiter has active weather patterns because it is seen with the colors of the planet."

"I found it interesting that if you took a boat onto Jupiter that you would never actually float, you would continuously sink with the gases just getting thicker and thicker. You would eventually start to sink into a liquid type substance but you would never actually hit a liquid. This is interesting because at first, I thought of putting a houseboat on Jupiter."

"Learning about the different planets and their similarities or slight differences. I also liked learning about what actually makes a planet, a planet. Having a reason behind why things are the way that they are."

"The IAU classification scheme was really interesting. Makes sense why Pluto is no longer considered a planet."

"The reason of why Pluto isn't a planet anymore. I've known that it was a dwarf planet, but I never understood it fully until now."

Describe something you found confusing from the assigned textbook reading or presentation preview, and explain why this was personally confusing for you.

"Never heard of a Cornish hen before. Is that weird or is that just me?"

"The self-maintenance of our Earth versus other planets like Venus and Mars; I think I just need some more explanation."

"I think it's weird that there is water on Mars. I guess I just don't imagine other planets having atmospheres like Earth does so when I think about water on other planets it seems like there would be water in space and that's weird. But when I think about it I guess it makes sense."

"The whole variety of greenhouse effects on different planets is a bit hard to keep track of. I'll probably forget each planet's particular greenhouse effect by tomorrow."

"Something I found confusing was how Venus has so much carbon dioxide. Is all of the water vapor of Venus gone out of atmosphere, or is it still in atmosphere and it is just too hot to condense?"

"Reading about the volcanic resurfacing on Venus was interesting and confusing. How would we be able to figure out how many eruption cycles Venus has had and are we able to predict the future eruptions?"

"I was curious to know if Earth will slowly become more hostile in the future alike Venus and mars. The textbook did not touch on the possibility but introduced the idea that Venus and Mars both were more habitable in the beginning."

"I found a little bit confusing reading about Jupiter's complex atmosphere and the belt-zone circulation."

"I find the jovian planets confusing in that they have no surface and are liquid. Just giant balls of liquid floating in space. Perhaps not so confusing, more strange."

"Whether Neptune or Uranus is the coldest planet. You would think that Neptune would be chillier because it's farthest from the sun, but Uranus has calmer weather patterns."

"I feel like I understood most of the things covered in this chapter, but I guess I don't quite get why Uranus is colder than Neptune. I read the explanation from your blog post, but I guess I just don't understand why its orbit is so tilted. What made it like that? Why isn't Uranus the same temperature as Neptune?"

"I would like more explanation on ice giants because I am having trouble understanding what causes them to be the way they are. More on the Cooper Cooler™ effect?"

"Being able to define a planet and what that is exactly. I understand it, but it's still kind of confusing to me."

"What made scientists change the classifications of a planet? Why did the IAU make Pluto a dwarf planet?"

Identify the relative amounts of these characteristics for Venus, compared to Earth. (Only correct responses shown.)

Interior core heat, today: about the same as Earth [55%]
Geologic activity, today: less than Earth [71%]
Volcanic outgassing, up until now: about the same as Earth [58%]
Heat from the sun: more than Earth [87%]
Amount of atmosphere, today: more than Earth [77%]

Identify the relative amounts of these characteristics for Mars, compared to Earth. (Only correct responses shown.)

Interior core heat, today: less than Earth [94%]
Geologic activity, today: less than Earth [87%]
Volcanic outgassing, up until now: less than Earth [77%]
Heat from the sun: less than Earth [94%]
Amount of atmosphere, today: less than Earth [94%]

Which jovian planet has the coolest interior temperatures?

Jupiter (most massive).	[0]
Saturn (most prominent rings).	** [2]
Uranus (least active weather patterns).	******************** [20]
Neptune (farthest from the sun).	********* [9]
(Unsure/guessing/lost/help!)	[0]

I believe Pluto should be a planet.

Strongly disagree.	** [2]
Disagree.	******* [7]
Neutral.	*********** [11]
Agree.	****** [6]
Strongly Agree.	***** [5]

Briefly explain your answer to the previous question (whether Pluto should be a planet).

"If pluto were to be included as a planet, it would create argument to include tons of other planets like Eris that fit the plutos qualifications for planethood sometimes better than pluto (its bigger)."

"I think any planet-type object in our solar system should be a planet, but what do I know?"

"It seems funny that in 2006 we lost a planet. We went from nine planets to eight planets. Pluto is still a planet but is in another class called dwarf planet due to its size. In my opinion we need to restore the solar system to its former nine-planet glory."

"I do not have enough information to support a claim on whether or not Pluto should a planet. I am not very familiar with the subject. "

"It's orbit is affected by other planets and does not dominate its own orbit."

"Because, although Pluto has two of the three requirements for a celestial body to be called a planet (namely, (1) it has an orbit around the sun; (2) it is massive enough to be rounded by its own gravity); it doesn't have the third requirement: it hasn't cleared its own orbit path around the sun (it's not gravitationally dominant)."

"Pluto deserves to be a planet ."

"Scientifically I understand why Pluto is considered a dwarf planet instead of a planet, however my nostalgia on remembering Pluto as a planet as a kid gives me a slight bias."

"It is what it is."

"I think that Pluto is an interesting subject, but I'm not really emotionally attached to it. I understand the scientific community's reasons for changing its classification. I do believe that Eris, Ceres and company could all be classified as planets in addition if the accepted classification had been different. I don't have very strong opinions on the subject one way or the other, and I don't think that Pluto's planethood--or lack therof--should detract from our interest in it."

"I always knew Pluto as a planet so I would have to let it stay as a planet for my nostalgia."

"Does it really hurt to just call Pluto a planet? Pluto was always considered a planet when I was a kid, it was taught to me that way. I'll never accept Pluto as anything other than a planet, that deserves to be called one just as much as the other planets!!"

"I can understand why the IAU classified Pluto as dwarf planet because it is so similar in size to other objects in the Kuiper Belt. Some of these ice-body objects have their own moons too, so they are practically Pluto. Most people think of planets as larger than Earth and Pluto is itty bitty in comparison to the other planets in our solar system."

"Honestly, it's more of an emotional planet, because I went through elementary school with it being a part of our solar system (and it was my favorite planet, other than Earth, with Jupiter as my second) and then it was just taken out. Technically and scientifically I understand that it is a dwarf planet, but I'd still like it to be a part of our solar system."

"I actually went neutral since astronomers know why it does not reach the standards of a planet."

"Ever since I was little everyone said Pluto wasnt considered a planet. Till this day I don't care if it follows the definition of a planet, all I care about is that Pluto is still up there next to all the other planets so It should be one just cause its there."

"Classification is important in the sciences. knowing exactly what an object is can put data into context. Arguing over how to classify something is a waste of time and distracts from some of the dwarf-planet's interesting features and traits."

"Pluto orbits the sun and it also has a round shape. This gives it two out of three yes's plus it was already a planet so it should get to be a planet again."

"A planet to clear its orbital may have some relevance to the proximity to the sun when they formed and the Kuiper belt shows the result when a planet doesn't have that proximity. possibly to be defined Kuiper planets."

"I would say so because it was deemed a planet earlier but at the same time their are other planets that had better qualifications than Pluto but were not deemed planets."

"Pluto passes two of the three IAU qualifications. I don't think Pluto has a strong enough gravity to pull in or eject another object like a moon for example. Therefore it cannot be considered a planet despite its rounded shape and rocky characteristics."

"I defer to the IAU on such."

"I believe Pluto should be a planet because it orbits the sun and has an atmosphere when close to the sun."

"Human nature tends to cause us to want bring everything together into a family. This leads to feelings of hurt when a member of the family is dismissed. We often view the planets as our 'solar system family,'" therefore, by excluding a member, the family unit is seen as having been torn apart which tears at heartstrings. Bring Pluto back, he's cute."

"I do think that since Pluto didn't meet all the criteria to be a planet, it shouldn't be called one. It still doesn't make my heart hurt any less that they took it out though."

"I understand why it's not a planet but it does have its own moons. why does it depend so greatly on the planet's size if its considered a planet or not? just because Pluto is a dwarf makes it that much less of a planet?"

"According to the textbook, Pluto isn't considered a jovian or terrestrial plant. It also states that 'an object must be large enough to dominate and gravitationally clear its orbital region or more, or all, other objects.' So according to these standards Pluto maybe cannot be a planet."

"Pluto is classified as a dwarf, so I guess it shouldn't be a planet. However, that was due to recent updates in what classifies a planet and what doesn't, hence why Pluto was considered a planet for more than 70 years."

"Using the current system it doesn't meet the criteria. The classification system may change, and since it is too far for me to realistically visit, it doesn’t affect me that much so I don’t have a lot of emotional investment."

"Pluto should not be classified as a planet because it has little mass and does not dominate its orbit. Similar objects have been found in the Kuiper belt, so it doesn't live up to IAU's planet standards. Poor Pluto."

"After reading the part in the book about Pluto it shouldn't be a planet, it wasn't able to push other things out its orbit with its gravitational pull."

Ask the instructor an anonymous question, or make a comment. Selected questions/comments may be discussed in class.

"I'm relieved to have a break from spatial reasoning, it's obviously not my strong point."

"The concept that a planet needs to be geologically active in order to maintain its habitability is fascinating, and somewhat debatable. Couldn't a greenhouse dome provide conditions on a geologically inactive planet that would make habitation possible?" (Yes, especially since it's not possible to terraform Mars.)

"How come Mars is being investigated for habitability and not Venus?" (There has been some speculation on what would be required to terraform Venus, but Carl Sagan conceded that it is probably too far gone.)

"Venus is pretty stinking hot if our probes can only last a few hours on its surface... Venus is the 'hot lava' game in real life!"

"'Jovian' is a cool word. Really rolls off the tongue, unless I am saying it wrong?"

"Saturn's rings are made of ice particle/chunks. Theoretically, could that be a good water source when/if we become an interplanetary species? Or are there more accessible water sources in solar system?" (Maybe, but Saturn's moons (along with some of Jupiter's moons) have water ice as well.)

"More about the other planets that could have been planets."

"Is it likely that the junk in the asteroid belt or Kuiper belt could attract and become a planet in a few billion years, or is the way planet-making period in this solar system over?" (The asteroid belt will keep on as distributed debris, because of Jupiter's disruptive gravitational influence. Similarly for the Kuiper belt, due to all of the jovian planets.)

"Do you think Pluto should be a planet?" (Eh. It is what it is.)