De-mystifying Martian Clouds

 Two of the lab's PhD students have just published analysis on how Martian clouds interact with sunlight in companion papers over in the Planetary Science Journal! The results represent work on thousands of images of the sky taken by the Curiosity Rover over more than ten (Earth) years and describe the thickness of the clouds we saw and give information on the crystals that make up those clouds. How can you use pictures of clouds to figure out what they are like on the scale of less than a thousandth of a cm? Read on to learn more!

by Alex Innanen & Conor Hayes

Here at PVL, we’re a big fan of Martian clouds. For over eleven (Earth) years, we’ve tasked our favourite PVL-er, the Mars Science Laboratory (MSL) Curiosity rover, with staring up at the sky for a handful of minutes every few sols to capture the clouds drifting over its home in Gale Crater. Recently, we had two papers accepted that discuss some of these cloud observations. Our papers are very similar – both look at how light interacts with water-ice clouds during the same time of year (the Aphelion Cloud Belt, or ACB, season) using the same cameras (Curiosity’s Navigation Cameras, or Navcams). Between our papers we have 33 figures and over 15 000 words. Reading through that much material can be a daunting proposition! So, presented below for the cloud-curious is a brief and hopefully engaging summary.

Over the years, clouds have made frequent appearances on this blog, but as a quick refresher, yes, there are clouds on Mars! Some are made of dust, some are made of carbon dioxide, and some are made of water-ice. The water-ice ones are the ones we’re interested in, particularly those that form as part of the ACB. Every year, when Mars approaches its furthest point from the sun, it sees an increase in water-ice cloud formation around the equator. Gale Crater, where Curiosity lives, is just five degrees south of the equator, so it sees the southern edge of this belt of clouds. This is really great for those of us on the environmental science team – we get an opportunity every year to study these clouds and look for patterns in their behaviour from year-to-year. 

ACB clouds above Gale crater tend to be fairly tenuous – think of those wispy cirrus clouds you might see on Earth (shown above). Like cirrus clouds, they’re made of tiny crystals of water ice. (On Earth we don’t tend to specify what kind of ice, but on Mars the atmosphere can be cold enough for both water and carbon dioxide to freeze, so it’s helpful to differentiate between the two.) These crystals form when water vapour in the atmosphere condenses on some kind of nucleus – usually dust particles.

On Earth, atmospheric water vapour tends to freeze into a certain set of shapes depending on the specific conditions present when the ice crystals are forming.  These shapes have been catalogued thanks to the fact that we can actually fly into and directly sample our clouds taking close-up pictures of the ice crystals. While it may be possible that the ice crystals in Martian clouds have similar shapes to those in terrestrial clouds, we unfortunately cannot (yet) directly image them like we can here on Earth. Instead, we have to rely on some physics tricks. One of these tricks is looking at how light interacts with the clouds. These light interactions can produce a myriad of cool optical effects, but more importantly can give us information about the size and shape of these particles. This information is captured by what’s called a ‘phase function’. The phase function is a mathematical description of how much light is scattered by some particle at different angles from 0 to 180°, visually represented by a curve. The exact shape of that curve depends on the shape and size of the ice crystals in the clouds, so we can attempt to determine the nature of martian ice crystals by comparing our phase function measurements to those that have been made for ice crystals on Earth.

To see how light is scattered by the clouds across different angles, former PVL member Brittney Cooper came up with the phase function sky survey: Curiosity takes a series of 9 small cloud movies looking in different directions all around the rover, like you can see in the gif below.

From this we get information about how sunlight is scattered by the clouds at different locations around the rover and put together an average phase function for the clouds we observe throughout the cloudy season at Gale Crater. We’ve been doing this observation through four Mars years so far, which means that we can compare different Mars years to see if there’s any change in the phase function. The ACB is a very stable feature – it doesn’t change much from year to year. Likewise, the average phase function at Gale doesn’t change much either. Nor does it show much difference between morning and afternoon observations. So, what does that tell us? Mostly it’s just that – the phase function doesn’t change much from year to year, or from morning to afternoon. But this could also suggest that the water-ice crystals that make up the clouds aren’t changing.

Which brings us back to the question of what those crystals look like. This problem has been tackled a number of ways in the past, often by comparing an observed phase function with one for a known ice crystal shape. Brittney took this approach, as did Alex in their Master’s work. However, we found that none of the modeled ice crystal shapes fit our curves very well. This could be for a couple reasons – the particles Brittney looked at were much bigger than the water-ice particles that we tend to see on Mars. It’s also likely that the water-ice crystals are not forming the same shapes they do on earth.

In the phase function paper, instead of forging along directly comparing our curves to known water-ice crystal shapes, we took a slightly different approach. It turns out you can make a simple approximation of a phase function mathematically using what’s called a Henyey-Greenstein (or HG) function. There are two values that go into making an HG function – the creatively named ‘b’ and ‘c’.  Helpfully for our purposes, the b and c values also give information about the particle shape. If we look at the b and c values we see in the Gale Crater phase functions, they’re close to b and c values for rough, irregularly shaped particles – not those relatively simpler geometries we see in Earth clouds. It’s not as exciting as actually having a picture of what a martian water-ice crystal looks like, but it is still a solid starting point.

The phase function is important not just because it gives us information about the shapes and sizes of the ice crystals in the clouds, but also because it is a critical input into various models. These include Martian global climate models (GCMs), which must include the effects of clouds on the amount of light that is transmitted through the atmosphere. It is also important for the topic of our second paper: the opacity of the ACB.

A cloud’s opacity basically describes how thick it is. An opacity (or “tau”) of zero means that there are no clouds and all light passes through.  As tau increases, more and more light is blocked, either through absorption or reflection into new directions (also called elastic scattering). In theory, tau can be arbitrarily high, but at a certain point so much light is blocked that it can barely be measured. During the Mars Year 34 global dust storm in 2018, Curiosity measured a tau as high as 8.5, meaning that about 99.98% of the Sun’s light was blocked by atmospheric dust (hence why the solar-powered Opportunity rover did not survive the storm).

We use a fairly simple model to determine the opacity of water-ice clouds. The math is not particularly exciting, but in essence it takes the amount of sunlight reaching Mars at the top of its atmosphere and determines how much “stuff” there has to be between the top of the atmosphere and the ground to explain the amount of light that Curiosity measures. The phase function is important here because it tells us how much of that light is being indirectly scattered towards the rover by the clouds.

The opacity of ACB clouds has been the topic of a number of PVL papers before this one, most recently by former member Jake Kloos in 2018. That paper covered the first two Mars Years of measurements. When we began writing this paper, we had just passed five Mars Years at Gale, so we were very much due for an update! We had initially hoped that this would be a fairly straightforward paper to put together. Because our model had already been well-established in our previous papers, we thought it would just be a matter of running the new data through the old model. Unfortunately, once we did so, the results pretty obviously made no sense. As previously noted, the ACB doesn’t change much from one year to the next, so we’d expect that the opacities would stay pretty much the same from year-to-year. Instead, the opacities output by our model for the new data were all over the place! They were neither consistent with each other nor with the old data, so we had to go hunting for a reason why.

It didn’t take much digging to find the cause. When we plotted the opacities as a function of each measurement’s distance from the Sun on the sky, there was a sharp increase as we got closer to the Sun. There’s no physical reason why clouds near the Sun should be thicker than those elsewhere, so our model was clearly breaking down in this area. The culprit, as it turned out, was the phase function. All of our previous opacity papers had assumed that the phase function was flat, taking on a single value of 1/15 at all angles. The results from the phase function sky survey have shown that this is very much not the case near the Sun, where the value of the phase function rapidly increases.

By assuming that the cloud opacities shouldn’t change very much over the ACB season, we were able to derive another phase function for ACB clouds, one that is reasonably similar to the one found using the phase function sky survey (which is good since we're all looking at the same clouds using the same cameras on the same rover!). After adding this new phase function into our opacity model, we were finally able to take a proper look at how ACB opacities have changed over five Mars Years.

In short, much like the phase function itself, they don’t really change at all, which makes sense given the consistency of the ACB between years. Notably, these new results invalidated one of the findings of Jake’s 2018 paper: that ACB clouds in the morning tend to be thicker than those in the afternoon. Although thicker clouds do appear more frequently in the morning in our new data, it doesn’t seem that this is the case generally. In fact, we found that observations in the morning tend to be taken closer to the Sun than those in the afternoon, which was artificially increasing their opacity values when using a flat phase function. Why didn't Jake include this in his paper? Without access to as much data as we have now, he simply didn't know that martian clouds behaved this way! (no one did) Therefore, while it can feel a little awkward calling out a former labmate’s paper as incomplete, science ultimately moves forward through incremental methodological improvements.

Just for fun, we also compared our opacity measurements with those taken by two cameras orbiting Mars: the MARs Colour Imager (MARCI) onboard the Mars Reconnaissance Orbiter (MRO), and the Emirates Exploration Imager (EXI) onboard the Emirates Mars Mission (EMM) Hope probe. Our methods did feel a little cyclical (assume the opacities don’t change much to derive a phase function, then use that phase function to conclude that the opacities don’t change much), so if we can match our ground-based measurements with those taken from orbit, we can have more confidence in our results.

Happily, the agreement between the MSL and MARCI/EXI measurements ended up being excellent, matching almost exactly with a few differences that can generally be explained by regional dust storm events that aren’t accounted for in the orbital data’s models. Thus, we can confidently say that our results reflect reality and probably aren’t a consequence of any assumptions that we made.

And don't forget to check out the papers themselves, available open-access at

Hayes et al. (2024)
Five Mars Years of Cloud Observations at Gale Crater: Opacities, Variability, and Ice Crystal Habits
&
Innanen et al. (2024)
Three Years of ACB Phase Function Observations from the Mars Science Laboratory: Interannual and Diurnal Variability and Constraints on Ice Crystal Habit

The Crunch

There comes a point when working on any large project when you can run into roadblocks or motivation can flag. This is almost guaranteed with something as long and as challenging as a PhD. Indeed, statistics suggest that in Canada about a quarter of science and engineering PhD students do not complete their degrees within 9 years (as of 2013). Sometimes, the greatest challenge can arise just before the end in "The Crunch" to finish, as Dr. Kevin Axelrod, our new Postdoctoral Fellow attests in this week's very personal post below. But if you find yourself in this situation, don't loose hope!  As the saying goes, it's often darkest just before the dawn.

(Photo above courtesy of Dr. Axelrod: "The view from the roof of the main building of the Desert Research Institute.  I spent a lot of time up here over five years, all four seasons.  It’s that nice.")

by Dr. Kevin Axelrod

So, it’s been a pretty crazy 12 months.  In January of 2023 (one calendar year before this blog is being posted), I was lying on the couch for two straight weeks in my shared house in Reno, Nevada, recovering from leg surgery, high on hydrocodone, and needing my housemates to get food from the kitchen for me (thanks, Heather and Brie).  Not appearing in the lab at the Desert Research Institute for two full weeks, I still had not completed the experimentation for my second publication of my Ph.D. research at the University of Nevada at Reno.  I still did not have a set date for when I would defend my dissertation and graduate from school, and quite frankly I did not yet know where my life was going.  And, believe it or not, I had never heard of York University.  

I had spent the last year and a half worrying about where my research was headed and how it was going to help me take the next step in life after graduation (if I even graduated).  At this point, I was supposed to be in “the crunch” - the last year of a Ph.D. tenure in which a student is supposed to devote their life, body, mind, spirit, overall being, consciousness, life-force, qi, etc. to their research and nothing else.  Instead, for two weeks, I watched Clarkson’s Farm on Amazon Prime (not sponsored, by the way) while eating chocolate pudding.  Not exactly the demeanor of someone who had spent the last 4.5 years of their life in graduate school and was now supposed to be in the crunch.  Of course, I could not walk and thus could not come into lab to work on my experiments, and I struggled to write anything because most of the time, I could not even sit up.  I felt stuck – I was seriously questioning whether I could graduate in August of 2023, which was a date delayed from a previous goal of May 2023, which was a date delayed from my original goal of December 2022 that I laid out in my prospectus defense.  

This was just 12 months ago.  And now, I am writing a blog for the Planetary Volatiles Laboratory, supervised by Dr. John Moores, at YorkU in Ontario.  Back in January, I would not have guessed that I would be here now. 

So, this blog is not about how cool my Ph.D. research is, a summary of an important meeting or event, or a case study of a planetary atmosphere.  This blog is about Ph.D. students in “the crunch”, who are anxious, unsure of their future, feeling consistently unprepared or inadequate, and always being very busy while still feeling like they get nothing done.    

Hopefully, that is not the case for most Ph.D. students who read this.  Hopefully, most Ph.D. students are constantly ecstatic about their research, enjoying all the once-in-a-lifetime experiences that they had dreamed about since childhood when they first watched Bill Nye the Science Guy or Mythbusters.  That was not me, however, and I know I am not the only one.  I had been working on this one singular project (bioaerosol chemistry, and more specifically pollen chemistry) for 4.5 years, and though it came with a lot of intrigue and enjoyment, I had also made many mistakes, suffered setbacks, and was disappointed with what I viewed to be a low level of progress. As a result, I was feeling very stressed and burned out – I just wanted to finally complete it and move onto new things.

After I got to the point where I could walk again, I returned to the lab with a new motivation - to get my life together.  And that involved two tasks: finishing my research on the volatility of bioaerosol constituents in the atmosphere, and also looking past my Ph.D. and finding a place where I could continue my passion for scientific research on a new project which would allow me to expand my knowledge further.  And I ended up finding such an opportunity with the PVL via a flyer that Dr. Moores posted on the American Geophysical Union website’s career listings.  

Upon my first interview with Dr. Moores, I knew right away that I wanted to join the lab – I was completely overwhelmed when he extended the offer to join.  I accepted.  It would be an exciting change of pace - a new project on the development of a functioning methane spectrometer for the Martian atmosphere (and so far, it has been a very exciting change of pace).  But, in March 2023 when I first interviewed, in the back (and front) of my head was a lingering doubt – would I actually be able to finish my Ph.D. research in time to move to Toronto and start research at YorkU in September 2023?

One thing was for certain – the pressure was on like never before.  Pressure not just to produce manuscripts, but to start a new chapter in life.  To self-improve, if you will.  In my opinion, that was the subject of my dissertation writing, even though self-improvement is never mentioned in it.  

And, for the most part, that pressure was good for me.  It made me more focused and motivated towards my bioaerosol research.  And as my leg improved, so did the state of my dissertation.  By the end of March, I completed the experimentation for my second publication and was busy writing the manuscript for it, while simultaneously taking care of in-lab work for my third research chapter in my dissertation.  By May, I had finished the writing of the publication and was wrapping up the in-lab research.  And by July 10, I was holding my dissertation defense.

Granted, the defense was far from perfect (almost nothing ever is in academia).  The night before was my most disturbed night of “sleep” ever. The morning of, I woke up at 4:30 AM and was instantly wide awake – something that had only happened one other time in my life, which was the morning of my prospectus defense two years earlier.  I held off on coffee that morning because it would have had no effect.  My jitteriness was already at a maximum due to the nervous energy surging through me. 
I was in a state of extreme anxiety.  But, I took solace in the fact that I had given the past year, “the crunch”, my best effort – motivated by my desire to make it to my postdoctoral fellowship.  And if my best effort was not enough, then oh well.    

The defense was an absolute fever dream – I don’t even remember most of it.  But it went well, and after two and a half hours I walked out of the presentation room with the blessings of my committee.  After living in Reno for five years, I was finally going to start a new chapter in life.  Provided, of course, that I take care of a few other things before I left, such as updating some of my writing and attempting to gather some results via a secondary analysis of some of my aerosol samples because one of my previous experiments failed.

But before any of that, I had another immediate task: attending my first in-person conference as a graduate student (no thanks to you, COVID), at the International Conference for Carbonaceous Particles in the Atmosphere (ICCPA) in Berkeley, California.  After my defense, my next task was to drive for four hours (on two hours of sleep) to California.  Though I was driving at night and did not arrive at the conference hotel until 2AM, it was one of the most euphoric drives of my life.  

The next day, I finally got to enjoy an in-person conference, as a reward for passing the defense.  It was a great time – I presented a poster on my research, sat in on an absurd number of exciting platform presentation sessions, met several new people and research groups, and certainly did not skimp on the catered wine.  By all estimates, it was one of the most enjoyable excursions of my time as a graduate student.

And one month later, I stuffed all my belongings into my sedan and left Reno, driving them back to my parents’ house before jumping onto a plane two weeks later.  

I will miss Reno.  I will miss the incredible natural landscapes around Lake Tahoe.  I will miss the excitement that I had back when I first moved there in 2018 as a grad student, realizing that I was about to take part in cutting-edge research for the first time.  And I will also miss a lot of the time I spent in lab over those 5 years.  I am forever grateful that I had a great advisor, a great program director, and great co-researchers and classmates, without all of whom I would not have graduated.  I will forever cherish the research topics that I was able to take part in while at the Desert Research Institute.  But there were certainly things that I will not miss: the many times that I made mistakes in my experimentation, the many re-do’s that needed to be done, the eternal frustration of trial and error, followed by finally obtaining a set of results that I thought were interesting enough to be published (and then writing about them for several months), only to have the manuscript murdered by some very truculent reviewers.  This cycle of frustration made it feel like I was stagnating – that I was not moving forward in research or in life.  It made bioaerosol research, a topic that I intrinsically enjoy, into something that stressed me out.  It’s the part of the scientific method that they do not show on Mythbusters.

So, to any current Ph.D. student who feels the same way right now, I would say: try to think about what you want to do after your graduation, even though it can be difficult to think about.  A visualization of your “next chapter” will get you over the hump.  Scientific research has both excitement and disappointment.  A Ph.D. may sometimes seem like it has more disappointment than excitement.  But after completion, you will feel just like the Mythbusters right after they blow something up: total ecstasy.  And that feeling will fuel my motivation for further research here at YorkU - hopefully I can keep it going for a while.    

The Center of the Universe – My Experience Interning at the Jet Propulsion Laboratory

We often encounter kids in our outreach work who can't wait to be astronauts when they grow up. Somehow this didn't have the same pull for me. Instead, I was mesmerized by the robotic spacecraft  exploring the distant reaches of the solar system. One facility came up over and over again in watching documentary after documentary on PBS about those probes: NASA's Jet Propulsion Laboratory in Pasadena, California. It was a thrill to visit while I was in graduate school. I still don't think I'm completely recovered from having a badge and a parking pass during the 90-sol prime mission of MSL while I was a postdoc!! Because of that, it's always a joy when one of our own here at PVL gets to experience this place for themselves. First there was Raymond, then Emily and, later on, Brittney. Recently, one of our PhD students, Grace Bischof (pictured above), had the opportunity to spend the winter working projects on-lab. She relates her experience below.

By Grace Bischof

In late 2020, I submitted a scientific proposal to the Technologies for Exo-Planetary Science (TEPS) program, with hopes of becoming a TEPS trainee. Upon a successful application, I was able browse through a list of TEPS collaborators with whom I could carry out a four-month long internship (assuming they accepted my inquiry to work with them). There was quite an appealing list of places to intern with – from national collaborators at Canadian universities and within industry, to international collaborators in institutions as far as Japan. There was one collaborator, however, that immediately jumped out of the page for me: Michael Mischna, who is a researcher at the Jet Propulsion Laboratory.

I had seen Michael’s name previously through a former PVL member – Brittney Cooper – who carried out an internship at JPL a couple years before I had arrived in the lab, and whose internship project with Michael inspired the bulk of my master’s thesis. Not only that, but as a member of the Mars Science Laboratory team since 2020, JPL was a place of legends to me, as JPL is the section of NASA that manages planetary robotic missions including the Curiosity rover. The idea of working there myself was something of a dream. In the summer of 2021, John reached out to Michael on my behalf to inquire if there was a place for me to carry out my internship with him, and luckily there was! Not only would I have the opportunity of working with Michael, but I would also be working with Leslie Tamppari, who had been project scientist on the Phoenix mission. 

After a year’s worth of delays due to the lingering pandemic, in January 2023, I packed two giant suitcases and flew down to Pasadena, California to start my adventure. After hopping off the plane at LAX (haha!), I was immediately greeted to views of the San Gabriel mountains, palm trees, and warm weather. I made my way to the house I was renting with four strangers, which luckily was not an internet scam, and spent the first couple of days unpacking and settling into my new home. 

 

(The first picture I took upon arrival in Pasadena. I couldn’t get over the palm trees.)

Although I had somehow found myself in LA during SoCal’s rainiest winter in a couple decades, nothing could rain on my parade that first day at JPL. Even the 5:30 am wake up call to ensure I was on-time for the first day’s onboarding activities felt exciting. I can clearly remember sitting on the LA city-bus as it approached the JPL gates and feeling awe at the opportunity ahead of me. The first day was spent filling in forms, giving my fingerprints, and taking a photo for my new JPL badge. Afterward, I met with Leslie and Michael to discuss the work I would be completing over the next few months, and then I was given a tour of the 168-acre lab by Michael. At JPL, you often need to have your walking shoes on to get from building to building.

Now, I should probably mention the actual science I did while I was at JPL before returning to the fun stuff. The plan was to work on two projects: the first was polishing some work I did in my master’s, using a radiative transfer model to determine the water-ice opacities at the Phoenix mission landing site. The second was to use the Mars Weather, Research, and Forecasting (MarsWRF) general circulation model to simulate the atmospheres of planets around stars with different stellar type, with future plans to expand this work to investigate the effect this would have on land-ocean distribution.

As science so often goes, the first project encountered many issues. A bug was found in the radiative transfer model which resulted in spending much of my time compiling and re-compiling, running and rerunning the model to determine the source of the issue. The MarsWRF work, however, went much more smoothly. I first spent a couple weeks becoming comfortable using the model. MarsWRF is a giant model, with many moving parts. I was set up with a NASA Supercomputing account so that I could run the model with relative quickness (often, this still took hours to days). Once I had the hang of using the model, I ran some cases simulating the ancient Martian environment to send to a team at Rice University who would use the inputs I provided for a Paleo-Mars lake model. Then, I got to work on the stellar-type investigation. I learned how to make changes to the source code of the model (which could be quite a task – altering several files to ensure that all the correct inputs were feeding into the correct scripts). Once I edited MarsWRF such that the user can define the temperature of the star they wish to simulate around, I ran the model for a Mars-like planet with a thin atmosphere around F-, G-, K-, and M-type stars. From this, we determined that, for the atmosphere that was set up, hotter stars will have more shortwave flux reach the surface of such a planet. This work was the first step in understanding exoplanet atmospheres around different stellar type and will eventually be applied more widely to understand the habitability of exoplanets based on star-type. Working on these projects with Leslie and Michael was such a delight, as they were incredibly supportive during this work.

Not only was the work I was doing at JPL extremely cool, but also the lab itself is one of the most incredible places to work. I was fortunate enough to have an office in the Science building (yes, there was big sign atop the front door reading Science). Although the office was very small and windowless, it got the job done, and I had two great office-mates. There was also ample seating around lab when I was craving a change of scenery. Sometimes I would work in the main cafeteria to be around the buzz of people conversing over their morning coffee, but my favourite place to work was the JPL mall. The mall is a big open area near the front of lab, which had plenty of tables set out to work or eat lunch outside in the fresh air. Working all day on the mall was how I managed to get a sunburn in February – a phenomenon I am not used to during Februarys in Canada. 

At JPL, cool things are happening all the time. In the main cleanroom, High Bay 1, they were assembling the Europa Clipper spacecraft when I was there. How amazing it was to look upon the brilliant people putting together a spacecraft that will one day be orbiting the moon of another planet so far out in the solar system. As cool as it is, this was one of the buildings I was only able to access if I brought an American with me. As a foreign national, there were several areas of lab that were off limits without an American escort – they take security very seriously at JPL.

 

The main cleanroom where the Europa Clipper Spacecraft was being assembled. If you look closely, you can see the workers in their bunny suits. Don’t be fooled by the worker at the front left of the picture – that’s a mannequin known as High Bay Bob, who is often moved around to appear to be carrying out various tasks. Currently, Europa Clipper has been removed from the cleanroom for testing, but a livestream of the cleanroom can typically be found on YouTube: https://www.youtube.com/watch?v=yKDA6smS9_k

One of the most memorable days for me was when I was able to visit the Mars Yard to watch the Perseverance Rover’s twin, OPTIMISM (Operational Perseverance Twin for Integration of Mechanisms and Instruments Sent to Mars) out into the yard completing some mobility testing. The Mars Yard is a big, sandy yard that is used to mimic the terrain of Mars. Here, OPTIMISM and MAGGIE (Mars Automated Giant Gizmo for Integrated Engineering – also known as Curiosity’s twin), are brought out for a multitude of testing purposes, including mobility and instrument testing, sample collection, or testing new autonomous algorithms. This day, I was also able to go into the garage to see MAGGIE, which was so incredible after working with the Curiosity rover for the past 3 years.

(Top: Outside in the Mars Yard with OPTIMISM as it completes mobility testing. Bottom: Inside the garage with MAGGIE)

Now, why is the blogpost titled, “The Center of the Universe”? Well, within the Space Flight Operations Facility on lab is the Mission Control Center. Here is where the data from the Deep Space Network antennas in Canberra (Australia), Goldstone (California), and Madrid (Spain) are managed. These giant dishes talk to the spacecraft that are currently exploring the solar system (and beyond for the Voyagers), and that communication is all funneled through the mission control room at JPL. This is also the room from which spacecraft, such as the Curiosity and Perseverance rovers, were landed on the surface of Mars. The story goes that former-JPL director, Charles Elachi, upon thinking about how all the information from the solar system comes into this room once said, “This must be the center of the universe!" There is now a big plaque in the floor in this room declaring it as the Center of the Universe. The JPL mission control center has someone within it, monitoring data around the clock to ensure there are no issues. In fact, since Southern California is so Earthquake-prone, Space Flight Operation Facility was built to be Earthquake-proof to protect the precious control center inside.

(Top: The Mission Control Center, where you can watch the DSN dishes communicating with spacecraft all over the solar system and beyond. Bottom: There is a superstition at JPL that peanuts must be passed around to ensure that launches and landings are successful, dating back to the 1960s. The lucky peanuts were eaten for Curiosity and Perseverance’s landings, among many others)

From my first day, the other interns who I met were incredibly kind and open. The JPL researchers and staff were all supportive and encouraging. I was lucky to experience only friendly and inviting people. The interns I met came to JPL from all over the world – Singapore, Australia, Italy, and Iceland, to name only a few – and were all open to having the most fulfilling experience at JPL, and in Southern California, as possible. I felt satisfied with not only the work I was doing at JPL, but also felt enriched by the experiences and memories I was making with my fellow colleagues.

Top: A hike up Echo Mountain trail which begins just north of Pasadena. This hike was organized by the Australian interns who had heard there was snow at the top of the hike. By the time we got there, one singular patch of snow about 0.25 square meters in size remained. They still made a few snowballs out of it to throw. Bottom: The view of the sunset from Joshua Tree National. My first time in the desert! We spent two nights camping in Joshua Tree, filling the days with hiking and rock-climbing (which I observed from the ground….).

The month of May came quicker than I could’ve imagined, and soon I was flying back to Toronto to continue my PhD back at York. While it was great to be back seeing my family, friends, and pets, my experience at JPL is one I will cherish forever. I feel incredibly grateful to have spent four months at such an amazing place, working with people who have such a hunger to explore what is out there in the universe. I will take the lessons I learned there with me through the rest of my degree – and hey, maybe in 2.5-years’ time when I’ve graduated with my PhD, JPL will have not seen the last of me (wink, wink, someone hire me!!).

Two Weeks in Killarney

Outreach is a key component of what we do at the PVL. So when PhD student Conor got the chance to serve as the Astronomer in Residence in Killarney Provincial Park they jumped at the opportunity.
Above: The Sun setting over the Killarney Provincial Park observatory.

by Conor Hayes

Earlier this summer, I spent two weeks at Killarney Provincial Park, located four hours north of Toronto, as part of the Astronomer in Residence (AIR) program run by the York Observatory. The AIR program is very new, having started just last year. I had considered applying last year, but ultimately decided against it given that I was very busy writing up my Master’s thesis at the time.  With that not being a concern this summer, I submitted an application to the program that was successfully approved. I had originally planned to head up to Killarney at the beginning of the summer, but that plan was foiled by me catching COVID for the second time three days before I had planned to leave. Although I felt normal by the time I was supposed to start, we decided to delay my term as AIR out of an abundance of caution.

My actual responsibilities as the AIR were not very heavy. Over the two week period, I was expected to help the park staff run six events: two public talks, two solar observing sessions, and two nighttime observing sessions. This schedule meant that I had a lot of free time to explore the park and the town of Killarney itself, which is about a 15 minute drive from the park. I got a lot of hiking in, which is something that I haven’t been able to do much of since moving to Toronto in 2020. The trails in the park were a bit more challenging than those I was used to, as they involved a lot of climbing up and down steep rock formations. The challenge was always worth it though, as I’d get stunning views of the surrounding area, including Georgian Bay and the La Cloche Mountains.

[Figure 1: Looking out over Georgian Bay from the Chikanishing Trail.]

Heading into the program, I was expecting that the public talks would be the most straightforward part of my time there, since I’ve given several in the three years that I’ve been here at York. The observing sessions were a little more intimidating because I haven’t done much visual astronomy recently and I wasn’t certain how well I’d be able to talk about the sky itself and point people around at interesting objects that they can see just by looking up. Instead, it very much ended up being the opposite.

Part of the reason for the difference between my expectations and reality may have been the fact that this was the first time (other than my Master’s defence) that I was giving talks in-person, rather than online. The mood of the audience can really make or break your confidence, and I was really challenged during my first talk (on our Curiosity cloud observation campaign) by the fact that it began at 8 PM, well after the Sun had set. This meant that I couldn’t actually see the audience at all, so it felt like I was just speaking into a void. The second talk, about the history of the search for lunar water, was almost derailed by a thunderous downpour that broke open the skies about five minutes after I started, but we gathered everyone under the roof of the amphitheatre stage, which turned it into a more intimate classroom-style presentation rather than a public talk given to a large space full of people.

The observing sessions were very different than the public talks. Obviously I did point out things on the sky like various constellations as well as Jupiter and Saturn, but they were more of an opportunity for people to ask me questions about whatever astronomy-related topics they were interested in. I had been expecting this,  but I will admit that I was a little worried that three years of focusing on a very small and specific set of subjects for my Master’s and the first year of my PhD had degraded my general astronomy knowledge. However, this didn’t seem to be the case, and the several hours I spent both weeks talking to visitors about any astronomy-related topics that they had on their minds were honestly probably the best parts of my AIR tenure.

While I did enjoy all of my interactions with the visitors and park staff, the real reason why the AIR program is hosted in Killarney is that it is a certified dark sky site, far away from any major population centres (something that you become acutely aware of when you realize that the nearest large grocery store is an hour away in Sudbury). Although I had been to some fairly dark sites (e.g. the Green Bank Observatory in West Virginia), I had never seen the night sky look like it did in Killarney. The familiar constellations, which are about all you can really see in Toronto, were drowned out by the sheer number of other stars. On several occasions, I just had to lie down on the ground and stare up at the Milky Way stretching itself across the sky. One thing that really surprised me was the number of satellites I could see during the night. In Toronto, it’s easy to see the ISS, but you’ll never really see any more than that. In Killarney, I would see one steadily marching across the sky about once every ten minutes for an hour or so after sunset.

[Figure 2: Close-ups of the Moon as seen through the Killarney 16-inch telescope, named Kchi Waasa Debaabing, Anishinaabemowin for “Seeing very far (as the eye can see).”

At night, when I wasn’t either staring up at the sky in awe or holding public observing sessions, I was engaging in astrophotography using the on-site 16-inch telescope. The weather during my time as AIR was phenomenal with only two nights clouded out, so I was out at the observatory every night, often until 2 or 3 AM. I came in with exactly zero astrophotography experience other than occasionally taking a photo with my phone’s camera through a telescope’s eyepiece. With 6+ hours of practice almost every night for two weeks (plus more than a few phone calls with Bruce Waters, the father of the AIR program), I improved quite dramatically, as can be seen below.

[Figure 3: Top row – views of Saturn and Jupiter at the start of my time in Killarney. Bottom row – Saturn and Jupiter again, now with two weeks of astrophotography practice.]

Having been back in Toronto for about a month now, there are some conveniences that I definitely missed up in Killarney, like cheap(er) groceries that I can walk to and cell service that’s better than a single bar of 3G connectivities. However, the sky here now looks depressingly bright and empty at night. If the AIR program continues into its third year, I will almost certainly be headed back to Killarney in the summer of 2024.

If you want to see more of the photos I took in Killarney, check out the AIR blog at https://www.yorku.ca/science/observatory/air/astronomer-in-residence-blog/

Completing an Internship at the Canadian Space Agency (CSA)

Last fall and into the winter term, PVL PhD student Charissa Campbell completed an internship with the Canadian Space Agency. Internships with industry, other academic labs and government are a key part of life at the PVL, giving graduate students the opportunity to get to know career paths close up during their studies.
(Above: CSA headquarters in St-Hubert, QC with the Agency's new logo in the top-left corner)

By Charissa Campbell

From September 2022 until April 2023, I was completing an internship at the Canadian Space Agency (CSA) on top of my grad studies. Being a part of the Technologies for ExoPlanetary Science (TEPS) NSERC CREATE gave me the opportunity to do an internship in another (or similar) area of space exploration. This could be with another researcher or with a company such as MDA who created the Canadarm that is on the International Space Station. However, one area of expertise in space missions that I was particularly interested to learn more about was how the government prepares for a mission through their space agency. Luckily, we were able to find someone at the CSA who connected me with someone who could teach me these skills.

Based on my experience with the Curiosity rover and surface missions, I was added to the team working on the Lunar rover. Even though my expertise is with Mars, it was great to learn on the differences between Mars and the Moon. One big change is that the Lunar rover will be at the south pole, while Curiosity is at Mars’ equator, so solar lighting is extremely different than what I’m used to. This lighting is not unlike what you would find on Earth if you were to travel far up north. There are even some parts of the year that do not see the Sun for several months. However, if you are at the equator then the amount of sunlight throughout the year is very consistent. When planning for a rover at the pole, knowing how the sun lights up your workspace is very important for understanding power conditions.

There are several objectives for the rover, but the main one is to find water-ice on the Moon. Water has been thought to be in Permanently Shadow Regions (PSRs) on the Moon due to the little-to-no sunlight these regions receive. Having water directly on the Moon would significantly help future crewed missions as not only do we need water to live, but the Hydrogen in water could be used as a source of energy for rockets launched from the Lunar surface. Knowing that finding water-ice is the main objective of the rover, 6 payloads will be added. Five will be Canadian and the other will be provided by NASA. Canadensys Aerospace Corporation was selected as the Canadian company to build the rover and develop the Canadian payloads. These payloads include:

    1)    Lunar Hydrogen Autonomous Neutron Spectrometer will detect Hydrogen to help indicate if water-ice is nearby.
    2)    Frozen Regolith Observation and Science Tools (FROST) imaging suite contains three specific payloads:
        i.    Lyman-Alpha Imager will identify surface water-ice by investigating lunar surface sunlight reflectance.
        ii.    Multi-Spectral Imager will identify minerals in the lunar soil
        iii.    Multi-Spectral Imager Macro is similar to (ii) but with much higher resolution
    3)    Radiation Micro-Dosimeter will measure the amount of radiation at the surface to help determine the safety for future human crewmembers on the Moon.

Even though the launch isn’t till 2026 at the earliest, it is amazing to see Canadian technology and knowledge being developed for scientific missions. It will be the first time that Canada will send something to the Moon. The announcement for the Canadian rover can be seen here: https://www.asc-csa.gc.ca/eng/astronomy/moon-exploration/first-canadian-rover-to-explore-the-moon.asp

Overall, I really enjoyed the internship and learned a lot that could help my future career prospects. For the first four months of my internship, I dedicated my entire time to the CSA and moved to Montreal to attend my internship in-person. Many interns were still virtual, but I wanted to fully experience what it was like working at an agency. This includes getting my own cubicle (with my name!) and my own badge that I had to scan multiple times to reach my office. The opportunity to do this in-person was too hard to pass up, even though it was relatively hard on my family as my husband and 2-year old son stayed back in Ontario. 

However, the CSA was extremely generous and allowed me to work-from-home every second Friday so that I could take the VIA train back home for that weekend to see my husband/son. I loved taking the train back/forth between Oshawa and Montreal and learned it was a great way to get some extra work done on the 4-hour one-way trip. At one point, my husband came down to Montreal with Arthur so he could see where Mommy was working for the past few months. 

One perk of working in-person at the CSA is the extensive library. They have a variety of books and offer weekly colloquium sessions. This was my son’s favourite part as he got to read and play with their space shuttles while I completed a meeting. Even though I did love being in-person and really getting to network (including meeting astronauts!) I decided to do the last four months part-time and virtual so that I could be home with my family and work on finishing up my PhD. 

Now that my time at the CSA is complete, I feel very happy with my decision to pursue this type of internship so that I could understand the finer details about how a mission goes from its early stages to being developed. It is rather a unique experience and I would recommend that if you are interested in an internship with the CSA to check out this webpage: https://www.asc-csa.gc.ca/eng/jobs/internships-and-student-jobs.asp. I look forward to watching the news in 2026 (or later) on the Canadian Lunar rover and its success on investigating water-ice at the Moon’s southern pole.

Coffee Cupping for the Novice

 

Ahh, coffee! It's practically a religion in science. Cups often fuel a late night working on a proposal or finishing a paper. Carafes are never far at research seminars and conferences. Chances are good that when you last made a new collaborator they were holding it in their hands. While some aren't picky about what they drink, others have very defined preparations and purveyors. For this week's post, PhD student Elisa Dong decided to take a deeper dive and reports back on a coffee cupping event that she recently attended. (see the bottom of the post for a description of the image above)

by Elisa Dong

The best description I have for the act and event that is coffee cupping, is to align it with the better known wine tasting. One sips at the drink at specific temperatures in standardized vessels, makes notes, and repeats this task to compare with another offering. Techniques vary a bit from taster to taster, but for coffee cupping, it is normal to have a shallow spoon that dips into the coffee, and suck it in quickly to aerate the liquid.

I went to my first (and to date, only) coffee cupping event some weeks back. The event details were forwarded from a friend of mine that I had introduced to pour-overs (a way to make coffee) some years ago. I reached out on my dusty instagram account (that definitely has a suspicious sounding fake name) asking to attend, and was informed that I was welcome. So, I showed up to a coffee machine distributor's workplace in the middle of the day and work week somewhere in the east end of Toronto. It took a few minutes to find my way through the building, which was partially office, partially showroom, and partially restaurant. There were maybe 25 of us, including the hosts of the event.

It became apparent very quickly that I was the only one who hadn't "cupped" before, so there was a brief explanation of the general process and what the plans for the day where. Here's what I got out of the process.

Prep:
-        there are 14 coffees on the table in similar sized and shaped vessels
-        each of the coffees had been ground minutes before, with the same mass and grind size

Sniff round:
-        we went around sniffing the freshly ground coffee and agitating the grains within the cups to get a deeper sniff 

Bloom:
-        each of the coffees was bloomed at the same temperature, and agitated with the same manner
-      the foamy surface was removed and we were left with coffee immersing in water, settling to the bottom of the cup
-        a water wash cup was available at each coffee to rinse off the sample spoon
 
Cupping:
-        we did three rounds of tastings.
-        The first was blind, shortly after the bloom (higher temperature),
-        round two/three took place when the coffees cooled to just above room temperature,
-      and after we were informed about what it was we were tasting (country, farm, origin, processing, extra details) 

Figure 1. Me with a spoon. Circles show placement of coffee cups on a very long table.

My takes:
-    I enjoyed samples 1-2 the most from sniffing the pre-soaked grounds, they had a "classic" coffee profile that I enjoy. Chocolatey and nutty
-    samples 3-5 smelled like tea and were barely distinguishable from the background
-    samples 8-14 smelled like various things, but generally fruity and floral, some more full bodied than others
-    unsurprisingly, the chocolatey smelling coffees fell a bit flat on tasting. The complex body and richness went away in the brew
-    sample 5 or 6 didn't remind me of cotton candy, as it did to another person, but it was bright and pungent
-    samples 7 and 8 tasted extremely similar, one more rounded out than the other in mouth feel. Both more dynamic and berry like
-    samples 9 through 12 were all variations on florals and stone fruits, one with a strawberry kick, and another with white florals
-    sample 13 was a more muted floral coffee
-    our wildhorse, sample 14, was predominantly silt by the time I got to it, but it was quite possibly the most flavourful coffee that wasn't a punch of acid in the mouth

Information (from memory):
-    samples 1-2 were Brazilian coffees from a large scale grower. These were grown and processed with the intent of being crowd pleasers. For purchasing purposes, they were the cheapest of the lots
-    samples 3-5 were from Rwanda (this was a surprise to many at the event). We received a brief political story discussing the origins of taking back parts of the coffee production from the government
-    samples 6 and 7 I have forgotten the origins of, but they were coffees that had undergone various types of microbial treatment as part of someone's PhD thesis. They might have been from Ethiopia
-    samples 8 and 9 were coffees from Mexico (another gasp) that had also received inoculation of sorts for various lengths of time
-    samples 10-13 were Geishas (alt: Gesha) from various regions in the world. Floral and fruity indeed. I confirmed I didn't see the hype, though I could see the appeal drinking in the range of coffee from time to time
-    sample 13 was sourced from Taiwan. The most expensive cup there due to the lack of desire to sell outside of the country
-    sample 14 was a guest brought coffee, allegedly from some producer that only sells to one roaster per country, and said roaster has to fly in to pick up the coffee (in Canada, it's Monogram). Regrettably, I cannot remember what farm it was (Elida perhaps, I'm sure someone can correct me)

I highly recommend giving cupping a go! Whether it's for coffee or for something else. Having two cups of liquid brewed under similar conditions and throughout cooling is a fun way to train the palate and perhaps your appreciation for various tasting notes. I, for one, am still on the hunt for the perfect chocolate/nutty/toffee combo that actually tastes like it smells. One day. I left the event only slightly caffeinated and with a list of shops to check out to reduce disappointment in the Toronto coffee scene. We also pulled shots of an experimental espresso that tasted like battery acid + mango. Good stuff. Perhaps unsurprisingly, I also found that some of the individuals there shared similar hobbies and had the same complaints about coffee. Spontaneously attending free events that sound fun is not as difficult as I thought it would be, though it does seem that they are mostly run through social media.

Shout-out to Stealth Coffee Systems and Forward Coffee for running the tasting! And all the nice roasters/buyers/hobbyists that were real friendly and happy to share their thoughts. For a future blog post, I might dig up an ancient report I made on coffee shops and their Yelp rating validity throughout San Francisco that I submitted as my work term report that year. A more detailed version of this post may be available later on my own blog at abstract-ED.me.

___

Caption for the image at the top of this article: In slightly unrelated content, I went coffee-hopping with someone I met at the event the next day. Look at this teeny tiny little Hario setup (can be seen at The Library on Dundas St.)! For scale, the carafe is less than 1 inch tall. Apparently you can buy these via gacha machine, or opened on ebay/etsy. If anyone is looking to send me gifts, you know where to go!

James Webb Space Telescope Update

 

The James Webb Space Telescope is able to view the universe in a truly new light. Below, MSc student Madeline Walters takes a look at some of the recent discoveries this new observatory has made. Image above: https://images.immediate.co.uk/production/volatile/sites/25/2022/01/JWST-galaxies-ba2f7b8.jpg

by Madeline Walters

It’s been a while since my last Webb update, but since then the space telescope has been busy! To kick off 2023, NASA released a statement [1] about how the James Webb Space Telescope (JWST) was used to capture the shadows of starlight cast by the thin rings of Chariklo, an ice small body located around 2 billion miles away from the orbit of Saturn. As the JWST observed Chariklo passing in front of a background star, the expected obstruction of that star's light occurred- a phenomenon called occultation- which allowed for the observation of a spectrum of the body’s surface. This showed evidence of crystalline water ice, which was previously only a guess from ground-based observations.
 
However, what surprised astronomers was that the starlight dipped twice rapidly before Chariklo passed in front of it, and then twice again as Chariklo moved away. These rapid dips in light were caused by the two thin rings of Chariklo - the first to ever be detected around such a small body. Since Chariklo is so small and far away, the JWST isn’t able to directly image the rings, but with occultation and the JWST’s heightened sensitivity, there is a hope that the composition of the rings may be isolated from the main body, allowing for further study.
 
Along with being able to get a closer look at smaller and more distant bodies with higher precision, the JWST has been showing us other things at higher resolutions than before. Take for example the side by side comparison of the ‘Pillars of Creation’ photos taken by NASA’s Hubble Space Telescope and JWST:

Image caption: A side by side comparison of the Pillars of Creation taken by the Hubble Space Telescope (left), and the JWST (right). Each image shows the same region taken in different wavelength ranges. The Hubble image is taken in the visible light range with different colors representing different molecules, while the JWST image is taken in the near-infrared range, allowing us to peer through the dust. (https://stsci-opo.org/STScI-01GF44F9Y10HZB8SPV2NZ8H6TZ.png)

On the left we have the Hubble image. This incredible and iconic image of towering cosmic dust in the heart of the Eagle Nebula shows us the primary components of what makes up these pillars [2]. Different gasses are represented by different colors here to allow us to visualize it better: blue is oxygen, red is sulfur, and green is both nitrogen and hydrogen. While the colors aren’t what we would see in real life, the structure is similar, since this is taken in the visible light wavelength range.

Now compare that to the image on the right of the same location taken by the JWST. Why is this different? It’s not just because the JWST has larger mirrors-it also comes down to the wavelength range between Hubble and JWST. Hubble observes in the ultraviolet, visible, and near-infrared ranges, while JWST observes in the near and mid-infrared range. This allows the JWST to pierce through obstructing dust and gas that shows up in the visible range, and show a view of the pillars we aren’t as familiar with, but isn’t any less stunning. More images reveal this difference between Hubble and JWST, such as these images of the Southern Ring Nebula, with Hubble on the left and JWST on the right:

Image caption: A comparison of the Southern Ring Nebula (NGC 3132) taken by Hubble (left) and the JWST (right)Each is taken in different wavelength ranges with different colors representing different gases, showing varying level of detail of the region. (https://stsci-opo.org/STScI-01EVVFSTZYZJJKAB41KA6AJ0HQ.png; https://www.nasa.gov/sites/default/files/styles/full_width_feature/public/thumbnails/image/main_image_stellar_death_s_ring_miri_nircam_sidebyside-5mb.jpg)

With the JWST, we can see in higher detail the rings of gas and dust thrown out by a dying star that we previously could not see in the Hubble image. Hubble has taught us some amazing things about the universe, but with the JWST, we can shed new light (in longer wavelengths) on objects in space previously unseen. Even just a few days ago, the JWST detected a dust storm raging on an exoplanet about 40 light years away [3]. The more we’re able to see, and the further back in time we are able to peer, the more we can learn about the universe and our place in it.

[1] https://blogs.nasa.gov/webb/2023/01/25/webb-spies-chariklo-ring-system-with-high-precision-technique/

[2] https://www.nasa.gov/image-feature/the-pillars-of-creation

[3] https://webbtelescope.org/contents/news-releases/2023/news-2023-105