Is it March already? Where the time has gone…

Research discussion

Let me begin with a brief research review. I went to Georgia presidents (family day?) weekend for Deceptacon. I had a tons of fun playing, moderating, and volunteering. While there, I took some time to stop by GA Tech to meet with my new collaborator, Jacob Buffo. We discussed the model, goals, expectations, etc. I took some time to talk to him about platelets. These are tiny flakes of ice that form in the suspended water when super-cooled water comes underneath the ice. It leads to these layers of platelets that are more porous (Figure 4).

Figure 4 Dempsey et al 2010.png
Figure 4 of Ice cores from Antarctica, with a focus on different platelet layers. Dempsey et al. (2010)

I thought this sort of freezing may occur in Titan melt ponds, where freezing on the bottom may float to the top layer from buoyancy forces. However, Jacob didn’t think this was likely. Super-cooling plays an important part in this, and his work with melt ponds on Europa don’t show this. Furthermore, my initial interpretations that impurities in the ice were controlled by platelets was wrong. He is submitting a new paper on his melt pond work which I hope to write about more in depth later, but I can’t at the moment due to time and because it isn’t published yet.

I think the most interesting piece though is that there appears to be a relationship with the temperature gradient and the amount of salt in the ice. The result is that, deeper into a freezing melt pond the impurities drop off. This may introduce a problematic conclusion for Titan. Perhaps there will be substantial freezing in the ice, but it may be too close to the surface (freezing too fast).

One last thing I hope to discuss more is a paper, Santibáñez et al. (2019), that has only just been submitted about how bacteria and organic matter tend to freeze into ice much more effectively than inorganic material. This appears to be the case even for dead organics. This has the potential to be extremely important, because we aren’t dealing with salts on Titan. We are interested in the organics in the ice. I look forward to discussing this more at a later date.

CPSX Research Forum

I presented a couple weeks ago at the CPSX forum. I think it went well; I had good feedback. I was a little irked that there was such little turn out. Thanks to those that were able to make it though! The talk began by reviewing Titan and the reason it astrologically significant. I concluded that piece of the talk with a brief over view, of what it means to potentially have amino acids, and where that fits in the greater picture of life as we know it. I wanted to give perspective. I then continued by explaining how this was why Dragonfly has been proposed to go there. I then pivoted the talk to a more geologic one. I discussed Dr. Catherine Neish’s recent Astrobiology paper and how we can use impact craters to investigate for molecules on the surface (impact melt/water mixing with the organics). Then I used my master’s research to talk about how we can compare impact craters and identify the best candidates to search. I showed my depth to diameter plot before I introduced the large scale mechanics of how a impact melt pond would freeze. Then I explained how we can use rivers as a natural way digging in to find samples within the melt. I plugged my rim to diameter plot to illustrate how we can look for fluvial erosion (along with visual radar images). Then that was when I pivoted to the final stage of the talk, my newest project of investigating exactly how impurities would freeze in the melt. I think my worst part was the final part. It is the newest piece of my work, so it makes sense I would be less fluent in it. Nevertheless, I will need to practice that more next time.

Astrobiology Course

The course is going well. I am enjoying it, and I can notice that I am retaining a lot more information than I did in previous years. We did the midterm. With it, came feedback. I was surprised that it was fairly positive. Only one person said it was unorganized. I got a lot of complaints about the tediousness of the labs. To be fair, some of them are ridiculously easy, and I wonder if they’d honestly rather have more complicated labs. Well, we are about to see because I’ve updated the habitability lab and made it a bit more complicated! Jahnavi was working through the lab, and she found a problem with the greenhouse/ albedo site that we use to calculate planet temperatures. When it came to including the greenhouse effect, the model wouldn’t update. See below, we give Planet X (the white circle) the albedo and greenhouse strength of Venus, but it gives a temperature half of what it should be. It adjusts for albedo, but different greenhouse strengths wouldn’t make a difference.

habitabiltiy plot
University of Colorado Greenhouse Module solarsystem.colorado.edu

Therefore, I decided to restructure this part of the lab. Lets be realistic, this lab was so tedious and difficult to make work. Java was a hassle, and it really was not that exceptional of a program. Instead using it, we are now going to give them the equations and they are going to solve it. I still reference the UC module, and I even link to their planetary fact sheets. The difference is, they need to plug the values into the equation. It really isn’t that difficult, and it will help them get use to calculations in Excel before the Icy Moons Lab.

UC data
Background information: The lab now references the fact sheet, and gives the orbital distances for the equations.
temp eq
At the start of Part A: I explain the equation to them, clearly defining the terms, and give them the constants they need to solve it. NOTE: I just noticed a typo, Rp instead of Ro. It has been fixed.

The math is simple, and if they are creative, they will figure out how to speed through the calculations. They can compare results, while flexing their problem solving techniques. In part B, I elaborate on the three factors that control the greenhouse strength 1) amount of atmosphere, 2) fraction of greenhouse gases, and 3) effectiveness of the greenhouse gases. I had to give (1) and (3) which I pulled from the online module, and the use the fact sheet for (2). 

This also really cleans up the lab. The procedures were very tedious and crowded the page. Hopefully, this will be easier to navigate and more enjoyable.

Lecturing

I have lecturing pretty well figured out. I was behind due to the exam and the ice cancellations, but I have caught up. I think I may even move into next weeks material tomorrow. That said, I am worried that I spend too much time writing on the board. One student said what I was thinking, I write things that don’t need to be written. I am not about to stop. I want make sure I pace myself, and give them time to take in the info. I also don’t want to waste their time. I am trying to be cognizant of the problem to not over do it and to make sure I am focusing on the right things.

Updating other posts

In other news, I have updated my peanut cookie recipe. I finally have it down to a precise science. I’ve also updated my reading post with my February recap. Obviously, I spent time in my reading post discussing the television show Game of Thrones for whic the final season premiers VERY SOON!

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