Astronomy in-class activity: planet classification schemes

Astronomy 210 In-class activity 12 v.13.06.10, fall semester 2013
Cuesta College, San Luis Obispo, CA

Students find their assigned groups of three to four students, and work cooperatively on an in-class activity worksheet to discuss the evolution of how planets are categorized, and how to implement the current International Astronomical Union classification scheme to categorize different solar system bodies.





Some samples of student responses (fall semester 2008) to question 2(h) ("Discuss a plausible motivation for why it was necessary to revise the definitions of planets in the 1860s and in 2006") are given below. Students in each group are referred to by a confidential four-digit identification number.

Many responses discussed the narrowing of the planet definition in order to exclude a "multitude" of planet candidates:

"We were getting too many planets, in 1860 there were 200+ large bodies and in 1992-present there were [approximately 1,300+] bodies."
--0013, 1327, 4245

"Because of the massive amounts of large bodies that would have been considered planets."
--0217, 0911, 1186

"Because there were too many."
--1208, 3248, 9387

"[A lot of] planets are a lot of planets to track. If the large bodies in the Kuiper belt count why don't the bodies in-between Mars and Jupiter of the same size count?"
--3273, 3903

"Because of new discoverys [sic] of 'bodies' so they had to limit the definition of what an actual planet could be."
--1990, 2580

"Without the definitions it would include [too many] large bodies and that would be way too many."
--4555, 9259

"There are too many 'planets' like Pluto in the outer solar system."
--3912, 5805

Some other groups also discussed other plausible motivations, in addition to limiting the number of potential planets:

"They would be hard to determine because they haven't cleared their orbit even though they do have a shape 'rounded out' by gravity. It would be hard to study because there a lot."
-3089, 4207, 7120

"Because it would be hard to have an accurate scale to compare any two 'planets.' So thus limiting the requirements makes comparisons easier."
--2639, 4127, 8187

"The definition was too wide including objects that were extremely different from each other."
--2020, 8808

"Too many bodies to classify. Easier to maintain."
--0805, 7776

"Too many variations between [planets], too many planets. Needed new scientific classifications."
--1988, 5389

Other groups discussed other reasons, but still received full credit for their responses:

"The advancement of technology gives us more accurate ways of classifying our solar system."
--1307

"We want to explore the universe and classify it."
--4018, 6586, 5997

Astronomy in-class activity: geo-atmospheric cycles and histories

Astronomy 210 In-class activity 23 v.13.06.10, fall semester 2013
Cuesta College, San Luis Obispo, CA

Students find their assigned groups of three to four students, and work cooperatively on an in-class activity worksheet comparing the geological and atmospheric cycle histories of Earth, Venus, and Mars. Students are already familiar with the Earth's cycles from a previous learning cycle and quiz, such that if an entry is to be used more than once, then it should appear in the same box on other planets as it does on the Earth (e.g. "CO₂").

Students apply the individual effects of distance from sun and presence of greenhouse gases, but may result in more than one plausible result for the questions on the third page, as comparing the relative amounts of competing effects is not covered in the scope of this course.

Astronomy in-class activity: planet classification schemes

Astronomy 210 In-class activity 24 v.11.05.04 (revised), spring semester 2011
Cuesta College, San Luis Obispo, CA

Students find their assigned groups of three to four students, and work cooperatively on an in-class activity worksheet to discuss the history of planetary classification schemes, and implement the current International Astronomical Union classification scheme to categorize different solar system bodies.



Previous post:

• Astronomy in-class activity: planet classification schemes (fall semester 2008).
  Previous worksheet version, with sample student remarks on plausible reasons for redefining planets.

Found physics: turkey cooling

"...Imagine what would happen if you took a Thanksgiving turkey piping hot from the oven and immediately placed it in a freezer. (Consider a perfect freezer--one that can remove heat instantly and always stay at its set temperature.) Initially the turkey would be at the same temperature throughout (assuming that you had roasted it for sufficiently long). Only a very thin skin would immediately take on the temperature of the freezer. But soon, the outer layers of turkey meat would cool as heat diffused outward, even though the center retained its initial oven-like temperature. Eventually, of course, everything including the stuffing would cool off; that is, the temperature inside your turkey would depend both on the distance from the surface and on the time elapsed since you placed it in the freezer."
--Philip C. England, Peter Molnar, and Frank M. Richter, "Kelvin, Perry and the Age of the Earth," American Scientist, volume 95 number 4, p. 342 (2007)

Previous post:

The "Turkey/Cornish Hen Effect".

Related posts:

Bergman's Rule (wikipedia.org).

Allen's Rule (wikipedia.org).

Cream-in-coffee model: Jupiter vs. Saturn

081126-1060756
http://www.flickr.com/photos/waiferx/3062504322/
Originally uploaded by Waifer X

Cream-in-coffee model of Jupiter and Saturn weather patterns. Jupiter's core is hotter, and has more active convection and weather patterns, as evidenced by the self-mixing of cream in the cup of hot coffee, compared to Saturn's cooler core, which has less active convection and weather patterns, seen by the settling cream in the cup of cold coffee. (The secondary effect of sunlight bringing the cloud levels higher in Jupiter above the hydrogen haze, compared to Saturn is not modeled here.)

The "Cooper Cooler(TM) Effect"

081106-1060446
http://www.flickr.com/photos/waiferx/3018649612/
Originally uploaded by Waifer X

Cooper Cooler(TM) apparatus in action for testing the hypothesis that an off-center impact on Uranus, which may have tilted its axis, would have also cooled it adversely due to stirring its interior, compared to Neptune, which would have remained relatively static, and cooled off at a slower rate. Two bottles containing equal amounts of warm water at the same initial temperature are either put into a Cooler Cooler(TM) beverage chiller, and spun while deluged by a cascade of ice water, or placed in a static ice bath for an equal amount of time. Afterwards, the final temperatures of the two bottles are compared.

Found physics: "Turkey/Cornish Hen Effect"

081108-1060468
http://www.flickr.com/photos/waiferx/3016610525/
Originally uploaded by Waifer X

The "Turkey/Cornish Hen Effect," illustrating the effect of mass on thermal capacity. Low-mass objects cool off much quicker than massive objects, which cool off at a slower rate.

Astronomy quiz question: Mars' atmosphere

Astronomy 10 Quiz 5, Spring Semester 2008
Cuesta College, San Luis Obispo, CA

Astronomy 10 learning goal Q5.5

[3.0 points.] Which one of the following choices best explains how carbon dioxide (CO_2) molecules caused the recent evolution of Mars to diverge from that of the Earth?
(A) CO_2 from the atmosphere was removed without being replaced, causing Mars' atmosphere to become thinner and colder.
(B) More CO_2 was released into the atmosphere than could be recycled, causing Mars' atmosphere to become thinner and colder.
(C) CO_2 was removed from the atmosphere without being replaced, causing Mars' atmosphere to become thicker and hotter.
(D) Too much CO_2 was released into the atmosphere, causing Mars' atmosphere to become thicker and hotter.
(E) More CO_2 was released into the atmosphere than could be recycled, causing Mars' atmosphere to become thicker and hotter.

Correct answer: (A).

Student responses
Section 5166
(A) : 30 students
(B) : 19 students
(C) : 2 students
(D) : 4 students
(E) : 5 students

Previous post: Astronomy in-class activity: geo-atmospheric cycles and histories

Astronomy quiz question: Venus' atmosphere

Astronomy 10 Quiz 5, Spring Semester 2008
Cuesta College, San Luis Obispo, CA

Astronomy 10 learning goal Q5.5

[3.0 points.] Which one of the following choices best explains how carbon dioxide (CO_2) molecules caused the recent evolution of Venus atmosphere to diverge from that of the Earth?
(A) CO_2 from the atmosphere was removed without being replaced, causing Venus' atmosphere to become thinner and colder.
(B) More CO_2 was released into the atmosphere than could be recycled, causing Venus' atmosphere to become thinner and colder.
(C) CO_2 was removed from the atmosphere without being replaced, causing Venus' atmosphere to become thicker and hotter.
(D) Too much CO_2 was released into the atmosphere, causing Venus' atmosphere to become thicker and hotter.
(E) More CO_2 was released into the atmosphere than could be recycled, causing Venus' atmosphere to become thicker and hotter.

Correct answer: (E).

Student responses
Section 4160
(A) : 1 student
(B) : 3 students
(C) : 2 students
(D) : 11 students
(E) : 21 students

Previous post: Astronomy in-class activity: geo-atmospheric cycles and histories

Photoshopped planet fantasies

Solar System², by ThreeProngs
Worth1000.com
Amazing Astronomy contest

Sun notwithstanding, but the planets are not to relative scale...and why does Pluto persist being a planet?

Fruity, by LordPAK
Worth1000.com
Amazing Astronomy contest

Interesting metaphor for the similar, but somewhat different compositions of Earth and Moon.

Cracked Up, by LordPAK
Worth1000.com
Amazing Astronomy contest

The inner core of the Earth, while hot, is solid due to the immense pressures at the center of the Earth. However, should the pressure on that material be relieved, it would revert to being a hot molten liquid.

Astronomy clicker question: hot or not (the cornish hen/turkey effect)

Astronomy 10, Spring Semester 2007
Cuesta College, San Luis Obispo, CA

Astronomy 10 learning goal Q5.5

Students were asked the following clicker question (Classroom Performance System, einstruction.com) at the beginning of their learning cycle:

[0.3 points.] Which terrestrial planet has the hottest core?
(A) Mercury, which is closest to the Sun.
(B) Venus, which has the hottest atmosphere.
(C) Earth, which is the most massive.
(D) Mars, which has the tallest volcanos.

Correct answer: (C).

Student responses
Section 4136
(A) : 6 students
(B) : 3 students
(C) : 14 students
(D) : 10 students

Section 5076
(A) : 9 students
(B) : 7 students
(C) : 2 students
(D) : 4 students

The terrestrial planets are subject to the "cornish hen/turkey effect." Suppose a cornish hen and a turkey are both taken out of the oven, where they were at the same temperature. Allowed to cool off on the counter for an hour, the cornish hen (being much smaller) has cooled off considerably, while the interior of the turkey still retains a significant amount of heat. Thus small things cool off faster than larger things. The Earth has a hotter core than any of the other terrestrial planets because it is the most massive, and this results in its current of volcanic and tectonic plate motion activity, compared to the dormant or dead geological activity on the smaller terrestrial planets.

Terrestrial world icosahedra
Originally uploaded by Waifer X.