Recap: Term 4

I'm officially a G2! As of ~1 month ago, I've completed my first year of grad school and am 17% of the way through (assuming the average of about 5.7 years or 23 terms for Caltech chemists). I spent the summer researching without the distraction of classes, throwing myself even deeper into the world of teaching, and taking the time to appreciate my love of space.

Even though my days of summer vacation are long gone, it was a great term (even though I didn't do as much in the way of research as I would have liked)! Here are the highlights.

I became the new co-director for the Caltech Project for Effective Teaching (CPET). CPET is a group of grad students and postdocs dedicated to learning about and discussing teaching pedagogy to improve their teaching and helping others do the same! As a chemistry grad student who does astrochemistry from her office in the planetary sciences building, I don't feel all that connected (at least not yet) to the chemistry and planetary sciences divisions; instead I found community on campus in CPET. I am excited to spend the next two years supporting other grad students and postdocs in their teaching endeavors!

I was a STEM SuperStar for Project Scientist. I had the opportunity to speak to about 60 girls (ages 4 to 12 years old) at Caltech about my experiences as a scientist. The theme for the week during which I was a STEM SuperStar was "Mythbusters", so I started off by presenting three statements, one of which was a myth:

1. The spaces between stars is empty.
2. [Showing a picture of the Green Bank Telescope (GBT),] This is a telescope.
3. Stars and planets are formed from giant clouds in space.
(#1 is the myth.)

After having the young scientists guess which of these statements was a myth, I took them through my story of radio astronomy and how each of these statements played a role in my becoming an astrochemist. I started off with how I though the spaces between stars were empty as a kid (#1) but I learned that those spaces are actually home to giant clouds of gas and dust that we cannot see. I then talked about radio astronomy and how we use radio telescopes (#2) like the GBT to explore the invisible universe, including those giant clouds that eventually collapse into stars and disks of gas and dust that will eventually become planets (#3). It was an awesome and challenging experience (having a target audience of 4-12 year olds gives you a wide range of prior knowledge and levels of comprehension!), and it felt great to—as Scarlett wrote—"show people to their goals". Perhaps the most rewarding moment of the day was when one little girl said to me, "When I grow up, I want to go to space just like you!" (Me too, kid. Me too....)

I got to celebrate with my b'friend on his wedding day. On August 5th, there was one less Smith as my b'friend (best friend without the 'est') Derek Smith became Derek Lukens. Derek and I have been close friends since 8th grade algebra, so his wedding was something not to be missed. It was a great party, and I am so glad I made it back to PA to share it with Derek and Brad (you are two wonderful people <3).

Photograph by J. P. Photography

Photograph by J. P. Photography

I witnessed totality during the solar eclipse. Totality was a remarkable experience, and I had a great time road-tripping to Idaho with the family! 2,770 miles, 7 states, 7 National Park stops (+ some other cool places)... it was a stellar way to end summer.

I learned how to model spectra. As a radio astronomer, I receive spectra—electromagnetic fingerprints for different molecules (chemicals)—from a radio telescope. But just like when working on a forensics case, I have to first know where to look for fingerprints to analyze. To do this, I make models, something I have been learning to do over the past couple of months. These models show what a chemical fingerprint will look like and whether I can see it at all with a desired telescope. (This is important because before an observatory spends thousands of dollars on your project, they want to be confident you will actually see something with their telescope.)

To make a model spectrum, I first estimate how much of a molecule is expected in a given region of space. These estimates are based on a combination of previous calculations in similar regions and flat-out making guesses where there is insufficient data to draw on previous work. The next step is to make some assumptions; space is a complex place, so we treat it as simply as possible. Specifically, I make two assumptions for my models.

1. I assume my target cloud is at local thermodynamic equilibrium, or LTE. LTE means that there are no abrupt changes in things like temperature or density across a cloud, and any changes happen gradually as you move across an object. If my target weren't at LTE, there would be some complicated chemistry happening making the models much more difficult (and much less accurate thus less meaningful). Thankfully, LTE is quite often a safe assumption to make.
2. I assume my source fills the beam. As a telescope scans the sky, it will pick up signals from the target (yay!) and anything else nearby (grr). The "anything else", otherwise known as "background" emission, complicates things and more-or-less contaminates my crime scene. However, since molecular clouds are HUGE (much bigger than our solar system), it is safe to say that the target object will be large enough such that it is all the telescope sees.

Considering these assumptions and how much of a molecule I expect to see, I can construct a model of its spectral fingerprint, like the one shown below (different colors are for different molecules). These models tell me how good of a chance I have to see a given molecule in a given molecular cloud, thus I can use them to convince different institutions to let me use their radio telescopes.

I stayed up all night observing exoplanets with my friend Cam. While I study gas in between the stars, Cam studies the gas in atmospheres of planets orbiting other stars. Staying up until 7:30 in the morning to do science is quite a feat, so I joined in for moral (and some scientific) support.

I spent a lot of time with my wonderful and supportive family. My first year of grad school was so much fun thanks to my wonderful husband Alex and son Günther. Between our travels in and out of California, evening snuggles with Netflix, and all around good times full of laughter, being a grad student has been a fairly chill experience so far. I'm looking foward to another 4.7 years of SoCal adventures!

Enjoying a 360-degree sunset at totality during the solar eclipse in Stanley, Idaho!