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.)

Astronomy quiz archive: solar system

Astronomy 210 Quiz 4, fall semester 2019
Cuesta College, San Luis Obispo, CA

Section 70158, version 1
Exam code: quiz04S3re


Section quiz04S3re

0- 8.0 :	* [low = 6.0]
8.5-16.0 :	***
16.5-24.0 :	******
24.5-32.0 :	******* [mean = 26.5 +/- 8.6]
32.5-40.0 :	************ [high = 36.5]

Section 70160, version 1
Exam code: quiz04NDme


Section 70160

0- 8.0 :	** [low = 6.0]
8.5-16.0 :	***
16.5-24.0 :	****** [mean = 23.5 +/- 8.7]
24.5-32.0 :	********
32.5-40.0 :	**** [high = 36.5]

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.)

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

"The turkey/Corn hen theory and the core heat example it helped me better understand the function of what mass and core heat have to do with a planet."

"The way Earth is like a giant greenhouse and how it naturally cycles CO2 and keeps the earth running."

"That the further you are from the sun the colder the planet and the closer the hotter the planet. Venus is one of the hottest planets in the solar system."

"Venus's runaway greenhouse effect was extremely interesting and led me to wonder if the addition of water to the planet would counteract this effect."

"I am interested in the history how Venus became a lethal planet and what lead to it becoming the Venus it is today. I am interested in the craters and volcanoes that dot the highlands. I am interested the greenhouse effect that boiled the oceans of Venus and lead to it losing all of its water. One of the things that I am interested is how without plate tectonics Venus is able to gain new crust every half-billion years."

"That there is evidence on Mars that there were large amounts of water flowing."

"The part in the presentation where it talked about jovian planets. especially when it talked about ice giants, I was just amazed on how different on complex all the planets in our solar system are, just imagine what else is out there."

"I found jovian planets presentation interesting because I'm getting to learn about gas giants and ice giants."

"Uranus's insides are cooler then Neptune's even though its closer to the sun. I thought for planets that the closer the sun is the hotter it is."

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

"Outgassing?"

"A part of the presentation that I didn't understand that well was runaway greenhouse, I got a good grasp on it but just need some clarifications. I don't get what happens to venus' greenhouse gasses now that they can escape, where do they go?"

"The greenhouse effect on both the planets Mars and Venus."

"I am confused on Jupiter’s core. I am curious on why Jupiter and other gas giants has liquid cores instead of molten cores. I am curious as to how Jupiter effected the formation of the solar system."

"What I found confusing was the Copper Cooler™ effect."

"Why is Pluto (to some) called a planet? It's the size of a small moon or large asteroid, I know it has its own very tiny moon but there are (I imagine) many like it in the asteroid belt."

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 [27%]
Geologic activity, today: less than Earth [40%]
Volcanic outgassing, up until now: about the same as Earth [33%]
Heat from the sun: more than Earth [80%]
Amount of atmosphere, today: more than Earth [47%]

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

Interior core heat, today: less than Earth [73%]
Geologic activity, today: less than Earth [73%]
Volcanic outgassing, up until now: less than Earth [73%]
Heat from the sun: less than Earth [73%]
Amount of atmosphere, today: less than Earth [80%]

Which jovian planet has the coolest interior temperatures?

Jupiter (most massive).	[0]
Saturn (most prominent rings).	[0]
Uranus (least active weather patterns).	******** [8]
Neptune (farthest from the sun).	******* [7]
(Unsure/guessing/lost/help!)	[0]

I believe Pluto should be a planet.

Strongly disagree.	[0]
Disagree.	*** [3]
Neutral.	***** [5]
Agree.	***** [5]
Strongly Agree.	** [2]

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

"The IAU is an international group who decides what does and what does not classify a planet. I feel like their rules for classification and fair and just, and Pluto should feel special because they made an entirely new classification for it."

"I think it should be since it is orbiting the sun."

"I chose that decision because Pluto has both the characteristics of a dwarf planet and planet in my opinion."

"I believe it should be a planet because it is out in space and moves like the other planets and it is in space."

"My answer to the previous question is neutral because I don't mind the idea of people suggesting that Pluto should be a planet or that it shouldn't, personally I don’t know much about it or the topic to have an actual opinion."

"I don't know, but I do know it's way smaller than any planet out there and farthest one out there."

"Don't have any real reason to call it a planet and it is smaller than the moon."

"Based on what it says in the book it seems logical that it shouldn't be a planet. The only thing it really has that may make it seem like a planet is a moon but thats not enough."

"I can see the arguments on both sides of the scientific committee. It is too small to be a planet and it is in an orbit with its sister planet Charon."

"Why leave the underdog out of the equation?"

"Pluto was a planet when I was a kid so why change it? And it also orbits around the sun just like the other planets."

"It's an unnecessary argument. The scientists who chose to remove the planet title from Pluto have their own choice and are more qualified to decide."

"I think it should be a planets because there are some points when it comes closer than Neptune to the sun."

"I think that it is too small and it's controlled by [others' gravitational] forces."

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

"Can we talk more about Mars and Venus compared to Earth?"

"One thing I found confusing is if Mars is small and cold, how come any liquid boils on the surface of Mars?" (In order to boil a liquid such that it turns into vapor, you have to give the molecules in the liquid energy to free those molecules. If there isn't very much atmosphere outside the liquid, then you don't have to add as much energy to boil the liquid, as it is easier for the molecules to escape into a more empty atmosphere. Mars' atmosphere is so thin and cold that if you had liquid water (which is going to be relatively warmer), its molecules are now very free to escape into the atmosphere, and have enough energy already to do so, and so it will "boil" on its own.)

"So which of the four jovian planets has the coolest temperature? I am guessing it is Neptune as it is the farthest from the sun." (The heat that drives the weather for jovian planets comes from within, so the smaller jovian planets would have the coolest cores.)

"I really don't understand Jupiter. If its made up of gas, how does the gravity work there? Is there a core?" (There is a rocky core that started the process of pulling in gases to build up Jupiter; after a certain point there would be so much gas accumulated that its gravity would come from its gases rather than its rocky core.)

"What does 'jovian' mean?" ("Jove" is another name for "Jupiter" in Roman mythology, and in astronomy a "jovian" refers to a planet that is "Jupiter-like.")

"Why do people think Pluto isn't a planet? I've been told that since elementary school and I've never heard an answer why?" (We'll be discussing that in class on Thursday.)

"Please explain your view on the whole 'Pluto is/isn't a planet' debate. Is it a planet or is it not and why?" (Like Pluto, lots of planets that were planets are no longer planets. Ceres was a planet, but is no longer a planet. Also Pallas, Vesta, and many, many others. We'll discuss how the rules for determining what is (or isn't) a planet have changed several times over history, and the motivation behind this changes.)

"Does the Kuiper belt extend past the edge of our solar system?" (While the Kuiper belt extends from outside Neptune's orbit outwards, the Oort cloud extends a thousand times further out from the sun.)

Astronomy quiz archive: solar system

Astronomy 210 Quiz 4, spring semester 2019
Cuesta College, San Luis Obispo, CA

Section 30674, version 1
Exam code: quiz04n3Ni


Section quiz04n3Ni

0- 8.0 :
8.5-16.0 :	* [low = 9.0]
16.5-24.0 :	*********
24.5-32.0 :	************ [mean = 26.7 +/- 7.1]
32.5-40.0 :	******** [high = 40.0]

Section 30676, version 1
Exam code: quiz04Si3n


Section 30676

0- 8.0 :
8.5-16.0 :	***** [low = 9.5]
16.5-24.0 :	************
24.5-32.0 :	************** [mean = 25.1 +/- 8.4]
32.5-40.0 :	******** [high = 40.0]

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

Astronomy 210, spring 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.

"The section about greenhouse gases because I've heard the term used a lot before, but never really knew what it meant."

"How mass plays into the atmospheric density and the releasing of greenhouse gases of a planet. I also remembered when reading the section on temperature and distance from the sun/size, the example from class about the turkey and the cornish hen effect. This is what honestly made it interesting--your anecdote!"

"How studying the greenhouse effect of other planets can provide some insight into our own planet."

"I find it very interesting and alarming that the greenhouse gas cycles of planets go awry for different reasons. What happens if it happens to Earth?"

"How similar Venus and Earth were, but how the difference in distance from the sun made them so different."

"I was kind of blown away to find out that we've landed space probes on Venus. I didn't think anything could survive that!"

"How Venus and Mars have had problems with their greenhouse gas cycles (runaway greenhouse effect) especially because that is a problem we are having on Earth right now. Could it be inevitable?"

"I find it interesting that Mars once had a different climate that permitted water. I know that Earth changes, but when I think of other planets I just never really thought about how their climates and surfaces/atmos' might have changed. It also made me a little sad when the textbook stated at the end of the chapter: 'Mars is now a cold, dry world.'"

"I've known about scientists finding evidence of water on Mars before, but I had no idea of the scope of it. The textbook mentions the term 'outflow channels,' which were valleys cut away by massive floods that apparently carried around 10,000 times the volume of water from Earth's Mississippi River. I find it interesting because how much water could possibly be underground and maybe the original Total Recall movie had a pretty good idea going for them."

"I was intrigued about the possibility of oceans and earth-like atmospheres on the 'runaway' planets. Curious as to whether or not scientific advancements could cause one of them to replicate a life-sustaining environment."

"How jovian planets get their weather mostly from their core heat. Earth's weather is dependent on solar heat, evaporating water, causing rain, etc., etc. It's very 'out-in,' But jovian planets have a weather that's more 'in-out.'"

"That the surfaces of the jovian worlds were made of gas and therefore unable to be walked on."

"How to tell if something is actually classified as a planet. I thought it was a much complicated process than the IAU's three questions."

"I really appreciated the explanation for Pluto's updated status as a dwarf planet. I remember learning about the change when I was very young, and being so confused."

"To learn about the three questions that can be asked to classify whether or not an object is a planet. I never really knew what the qualifications were, and I was curious as to why Pluto was demoted."

"The way they choose to classify planets--we only have so much information and it changes a lot but they figured out a nice basic system to classify things with."

"The reasoning behind Pluto no longer a planet. After reading why, it makes more sense that Pluto is better defined as a dwarf planet."

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

"The runaway greenhouse model for Venus; I didn't really understand what 'stronger greenhouse effect' meant."

"Just a brief explanation on the surface of Mars and how some areas are younger and how it had water."

"I'd like to go more in-depth on the atmospheres of each planet."

"How volcanic activity is affected by the crust and its relationship with how a planet develops is a bit hard to understand."

"I think the greenhouse effect is something that I'm going to need to take some time to understand. I think I'll be able to get it, but I just need to think on it a bit longer. It's just confusing to keep everything straight in my head."

"Why every planet is so different."

"How Mars had flowing water at one point and now it doesn't. I just don't understand what caused the water to freeze."

"The IAU rules and classes were a bit confusing. While I could guess which depicted planetesimal was actually considered a planet, I could not truly tell the difference."

"A little confused on what classifies a 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 [36%]
Geologic activity, today: less than Earth [52%]
Volcanic outgassing, up until now: about the same as Earth [42%]
Heat from the sun: more than Earth [85%]
Amount of atmosphere, today: more than Earth [70%]

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

Interior core heat, today: less than Earth [91%]
Geologic activity, today: less than Earth [73%]
Volcanic outgassing, up until now: less than Earth [61%]
Heat from the sun: less than Earth [88%]
Amount of atmosphere, today: less than Earth [85%]

Which jovian planet has the coolest interior temperatures?

Jupiter (most massive).	[0]
Saturn (most prominent rings).	[0]
Uranus (least active weather patterns).	******************* [19]
Neptune (farthest from the sun).	*********** [11]
(Unsure/guessing/lost/help!)	*** [3]

I believe Pluto should be a planet.

Strongly disagree.	** [2]
Disagree.	*********** [11]
Neutral.	********** [10]
Agree.	******** [8]
Strongly Agree.	** [2]

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

"After the explanation of dwarf planets, Pluto is more similar to Eris and Ceres. Also Pluto is like Kuiper belt objects that are caught in orbital resonance with Neptune."

"I really want Pluto to be considered a planet. As silly as it seems kicking Pluto out is so rude. When I see the criteria for what makes something a planet it makes sense why Pluto would be more of a dwarf planet."

"Pluto isn't classified as a planet (though I wish it was) because it does not dominate its orbit."

"I cannot quite make out from the presentation whether or not Pluto is a planet. However, Pluto seems to rotate the sun, retains a spherical form, and appears to have a dominant orbit."

"Well, the states that one part of the criteria to be a planet in the Jovian system is that it needs to be 'large enough to dominate and gravitationally clear its orbital region of most other objects.' This is one reason why Pluto can't be one of us...it's just too puny."

"Why make Pluto a planet then kick him out; that's just rude."

"As much as I wish Pluto was a planet, Pluto isn't large enough 'to dominate and gravitation-ally clear its orbital region, or all, other objects.'"

"On one hand it orbits the sun and has moons and geological activity like other planets, but on the other hand it is so small and resembles many other 'dwarf planets' of a similar type. I think calling them dwarf planets is a happy medium."

"Pluto is not considered a planet because it is in the Kuiper Belt. Pluto also doesn't meet one of the IAU's criteria which is being able to be large enough to dominate/gravitationally clear its orbital region. In my <3 Pluto is still a planet though (I remember your bit about the legal drinking age. but I dont care. long live Pluto.)"

"I understand that by scientific qualifications that Pluto doesn't make the standard, but I suppose I have some nostalgic fondness for when Pluto used to be considered a planet when I was a kid."

"It has moons, and it is also young. Over time I think it will develop."

"Because I grew up with it a planet and when it changed I got really upset."

"Pluto has four more moons than Earth, it should be a planet."

"This isn't a joke. If you gain a place in a sports hall of fame, you can't be taken out. It's like the states. We've had civil wars over this kind of stuff. Once a state, always a state. Donald Trump still has a star on the boardwalk. We are better than this. Little people are still considered people. Pluto will always be a (dwarf) planet."

"From what I can tell it looks round, it orbits the sun, but I don't know if it dominates it's orbit so that's why I agree rather than strongly agree."

"I do not have more authority then established, professional astronomers to make that decision based on opinion and nostalgia."

"Mike Brown ("The Man Who Killed Pluto") spoke at an event that I was at for my old job. He convinced me!"

"On one hand I was used to Pluto being a planet. But i understand that due to its size and the discovery of larger planets farther out, in comparison that it just doesn't fit the qualities that we used to define a planet anymore. But at least they still call it a dwarf planet."

"I see both sides to the argument and just don't care either way."

"I don't believe it should be a planet because it isnt big enough to clear its orbital path. If it were considered a planet then shouldnt all of the other similar dwarf planets have to be considered planets as well?"

"It is not a planet because it does not dominate its orbit. The dwarf planet isn't able to bring in and project objects in and out of its orbit."

"According to the International Astronomical Union it passes the three questions so it should be a planet."

"I can see it going either way. Pluto does orbit the sun, but is shaped differently from traditional planets."

"I'm not much for nostalgia. Bye, Pluto."

"More educated and informed people than me should be the ones to make this decision."

"One less to learn about."

"According to the three questions asked for Pluto to be considered a planet, it doesn't appear to be so. Pluto does not appear to be completely round or be big enough to dominate orbit. I'd say no..."

"It is still circulating in our solar system but it does not meet the IAU's standards for what a planet is so I am neutral."

"I grew up when Pluto was a planet but I guess they decided that Pluto is not worthy of being a planet. I don't know much about it so I can't really argue against it or if I agree."

"I see why Pluto shouldn't be a planet but its just so sad because when I was in like first grade it was a planet. Then they took it away. Like taking a cookie away from a hungry college student."

"Pluto is one of the many frozen bodies around the Kuiper belt. It has not met the criteria to be a planet. To be considered a planet it needs to clear the debris from its original neighborhood."

"I disagree because I have taken three weeks of an astronomy class and therefore do not feel qualified to argue with astronomers. They are probably right."

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

"If greenhouse gases come from humans and manmade waste then how do Mars and Venus have them?" (Remember that the vast amount of greenhouse gases (which includes water vapor) were outgassed from volcanoes; this may be a lot or a little depending on how active Venus' or Mar's volcanoes were over billions of years.)

"How is there even water to freeze on Mars if liquid water boils away? Also, if Mars is a cold planet how does water 'boil away?'" (Most of the water on Mars escaped when its atmosphere was lost over time; remaining water is permafrost, permanently frozen underground. Liquid water would "boil away" on Mars because the air is so thin (basically nearly empty space!), the water molecules in liquid form would easily "jump away" from each other to escape into the thin air; this happens so violently that you would see it "bubble" away as it disappears into the air, which basically is what boiling is about. On Earth, where the air is much thicker, it's much harder for water molecules in to escape from liquid form, so you have to deliberately raise the temperature a lot to force them to "jump away" into the air.)

"The planets are interesting, but I don't know why they are separated into two separate sections; like what's the point?" (It's just useful to group the rocky terrestrial planets together to discuss their similarities/differences; and the larger, gaseous jovian planets together to discuss their similarities/differences.)

"I don't understand gas giants. If atmospheres can escape like what happened to Mars, and if gas giants are basically all atmosphere, why don't we see them dissipating quickly? If it's just because of mass, why are smaller planets like Uranus and Neptune just as much a gas giant as Jupiter and Saturn?" (Jovian planets are so much more massive than the terrestrial planets that they not only have enough gravity to hold on their their vast gaseous atmospheres, their gravity allows them to compress and squish the lower parts of their atmospheres from gaseous form into liquid metallic hydrogen or warm slushy ices.)

"Any reason in particular why we aren't talking about Jupiter's and Saturn's rings and moons? Just curious." (That's a whole additional quiz worth of material right there that we just don't have time for. However, many of Jupiter's and Saturn's moons are a lot like Earth (but with ice-covered oceans) or Mercury (small, rocky, lots of surface impact craters, cooled-off interiors), so if we covered them it would be more of the similarities/differences discussion we've been doing for the terrestrial planets.)

"I found confusing how Jupiter has a liquid interior, but not on its surface and about its magnetic field." (Since Jupiter is primarily hydrogen, think of it like a very, very tall stack of pillows, where the top pillow is the top of its atmosphere, and the bottom pillow is its core. The force of gravity will compress this "pillow stack," where the top layers are fluffy (the gaseous upper layers), while the bottom layers are more and more compressed, resulting in squeezing the gas molecules and atoms into a more compact liquid form. The circulation of this resulting metallic liquid in deep interior of Jupiter is what generates its magnetic field, much like the circulation of the hot, molten metallic interior of Earth generating our magnetic field.)

"Is the term 'ice giants' the kind of ice we have on Earth ('weird warm slushy ice layers')? Why is the ice warm?" (Water-rich gas found in the interiors of Uranus and Neptune will be warm (as planet cores retain heat), and be a slushy-ice because of the pressures bearing down from the upper layers, which squeeze and force the water to a more compact solid-ish form.)

"Thanks for the explanation to why Pluto isn't a planet."

"Do you consider Pluto a planet? What are your thoughts about Pluto?" (It was, and now it isn't. Such is life. Pluto just has to deal with it.)

"Could you share any info on the new planet 'Farout'?" (Classifying "Farout," or more officially 2018 VG1 would make a great midterm question.)

"When will we be using telescopes in this class?" (The next scheduled observatory night is for Wednesday after spring break. Weather permitting, of course.)

"Tips for studying for quizzes?" (Review notes from class (which are also posted on Twitter using the #CuestaAstr210 hashtag). Re-do the in-class activities. Go through the quiz question packets. Use the practice quizzes from last semester to measure your preparedness. Keep asking questions!)

"I am wondering if you have any videos on YouTube that I can watch to help me review the material presented in class." (I'll be posting links to videos for certain topics covered later this semester. If you do find one that you think would be useful for the current material, let me know.)

"I didn't have any questions. I am wondering if there are any kind of tutors for this class though." (I'm still looking for tutors for astronomy. Usually this is the last (science) class students take before leaving Cuesta College, so it's hard to find good students who stick around and can become tutors.)

"Does Mrs. P-Dog know she's called 'Mrs. P-Dog?'" (Yes. But she knew I was called "P-dog" before we got married.)

"Is that a real cat on your head or are you just standing in front of a cat poster?" (That's Pocahontas, the Rescue Bengal Cat--she even has her own Facebook page.)