Sunday, February 18, 2018

Will it run? (or: Important things to ask yourself when programming)

Last fall, PVL MSc Giang spent a productive term with Raymond Pierrehumbert's group at Oxford. In this post, he reflects on his experience from the perspective of a little distance as he looks forward to summing up his MSc work and assesses PhD opportunities. Above (planetary photojournal image PIA01111), a view of one of Io's forced atmospheric components - sodium - which contrasts with the volcanic emission and condensation of sulfur compounds that Giang modelled.

By Tue Giang Nguyen


While I was interning at the University of Oxford, I was involved in atmospheric modelling projects for exoplanets and grateful for working with prominent scientists in my field. As I returned home from the UK, I had briefly forgotten what Canadian winter was like and was promptly reminded as I stepped outside of the airport. Now that I have returned to York University, it is time to reminisce about the things I learned during my short 3-months stay at Oxford.
The atmospheric model I worked with started by recreating Andrew Ingersoll’s 1985 work on modelling the wind flow on Io. Useful assumptions, some more justified than the others, such as making sure the Ionian atmosphere is hydrostatically bound and neglecting Io’s rotation allowed for a simple one-dimensional model of the shallow wave equation. The gist of the dynamics in the model is that sulfur dioxide, abundant on Io’s surface, would sublimate or evaporate when illuminated by the Sun. The sublimated sulfur dioxide would then flow onto the nightside where it is much colder and the atmosphere would condense back onto the surface. This insight on thin and condensable atmospheres is useful for exoplanet research where tidally locked rocky planets would evaporate or sublimate volatiles on the dayside where they would condense on the colder nightside.

Friday, February 9, 2018

Ice on Mercury and the Moon: Why So Different?

 
 A comparison of the poles of Mercury and the Moon illustrates similarities and differences that PVL PhD Candidate Jake Kloos explores in this blog post. Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington/National Astronomy and Ionosphere Center, Arecibo Observatory.

By Jake Kloos

The research I am conducting for my PhD pertains to the polar regions of the Moon, which have been active regions of study within the planetary science community for over half a century. For a variety of reasons, interest in the lunar polar regions is centered around the presence of volatile compounds, principally water ice. Ice deposits have been detected within permanently shadowed regions (PSRs), which are regions within impact craters near the poles that are permanently shielded from the Sun. Due to the lack of direct sunlight, temperatures within PSRs are extremely low, enabling them to trap, and potentially preserve, molecules such as water that are wandering about the surface. While ice has been detected within lunar PSRs, the concentrations that have been inferred from remote sensing observations appear to be unexpectedly low, at only a few percent by weight.

The low concentrations of ice found on the Moon is surprising given what we know about ice concentrations on the planet Mercury. Mercury and the Moon share certain key similarities that led many to predict that the two bodies would posses similar amounts of ice: both are considered “airless” bodies and host PSRs near the poles that exist within similar temperature regimes (although Mercury’s PSRs are slightly warmer). Despite this, ice appears to be abundant at the polar regions of Mercury, with inferred concentrations in the range of 50 to 100 % by weight. Moreover, radar data unambiguously show enhancements in nearly all of Mercury’s PSRs, whereas many PSR craters on the Moon lack similar radar enhancements. In fact, some of the lunar PSRs that do show radar enhancements are subject to debate, as some researchers feel that ice may not be the best explanation as to the cause of the enhanced signal. The large discrepancy in ice concentrations on the Moon and Mercury does raise the question: why?

Proposal Writing 101

A few weeks ago, PVL PDF Christina Smith helmed her first major proposal on a $600,000 project. In this post she describes her experience and how it compares to other writing and proposing activities she has led in the past. (Image: "Coffee and a big stack of data", missyleone, flickr)

By Dr. Christina Smith

An very important aspect of academia is proposal writing. These are documents which do pretty much exactly what they say on the tin: they propose research into something. There are many different kinds: proposals to use instruments, proposals for job positions, funding proposals, proposals to become parts of collaborations, proposals to get on missions, and many more. In the past I've written short proposals to try (sometimes successfully, sometimes unsuccessfully- that's just how it goes) to get time on telescopes and I've written ones to go with fellowship and job applications, but this last week I had my first experience of grant (funding) proposal writing which is an entirely different experience!

When you write a proposal that goes along with a job application or a fellowship application (full or partial funding for your job specifically), the proposal generally focuses on the project, the skills and experiences you have to complete it, and any relevant past work. This includes a general level of background information to set the scene, as not everyone who reviews this proposal will be a specialist in your area. You have to make sure that any person in your general discipline will, by reading your proposal alone, understand what it is you want to do, and almost more importantly, why. In addition to what you want to do and why, you have to prove to the reader that you are definitely capable of carrying out this project that you are proposing. This requires a fair bit of “blowing one's own trumpet” so-to-speak, but in a way that is backed up by evidence. So you have to describe what you've done in the past and also explain why that is relevant to what you're doing now.

Tuesday, January 23, 2018

Getting the Amazing Opportunity to do Outreach with the Ontario Science Center

As part of our work on the Ontario Ministry of Research, Innovation and Science's ERA program, we've been developing innovative ways to communicate rover operations to the public. Earlier this month we tried out a test of one of our events at the Ontario Science Center. Leading the charge was PVL MSc Charissa Campbell.

by Charissa Campbell


In my opinion, science outreach is one of the most important aspects of any public program. You get to teach people of all ages and can even encourage them to pursue science as a career. So, when our research group first discussed putting together an outreach program for high school students that would be like mission operations for a Martian rover, I was immediately on-board. Some of us are currently members of Curiosity’s mission operations team (including myself) so it was great to take that knowledge and adapt it. I’ve personally engaged in outreach programs in the past and still do on a regular basis with my young siblings, so I was excited to also be a part of this, especially in more of a leadership role. 

If you are curious about our May 2017 outreach program, you can check out Brittney’s great blog post: http://york-pvl.blogspot.ca/2017/05/analog-rover-missions-more-than-just.html. This was only the first of two successful runs in 2017 with varying levels of complexity. We knew changes had to be made from the first run, so we decided to broaden the roles and meetings to ensure participants didn’t get lost in the complexity. This did not, however, fix all of the issues from the first run.  Instead, we now had the opposite problem: the roles had become too broad. In the end, we identified the major problems with the program and made edits averaging the first and second run. Now in 2018, we have successfully completed a third run with volunteers at the Ontario Science Centre.

Wednesday, January 10, 2018

How to make your own moon

In the first installment of 2018, our resident experimental PDF discusses retrofitting our planetary simulation cryovacuum chamber to simulate a nearby environment: that found in the permanently shadowed regions of our own moon. An image of our first run can be seen above.

By Dr. Paul Godin


One of the experiments happening at the PVL is called the Aniu Investigation, which has the goal of testing to see if frost could be detected in shadowed regions of the moon using reflected starlight (Lyman-alpha radiation, 121 nm). Unfortunately, the moon is quite far away from York University and expensive to get to, so we’ll need to simulate the moon in the lab.

To build a moon in the lab we’ll need the following “ingredients”:

1.     A stainless-steel vacuum chamber.
2.     A vacuum pump.
3.     Liquid nitrogen.
4.     A “cold finger” heat exchanger
5.     Simulated lunar regolith
6.     A UV lamp.

Once we have all the above we can start building our moon. First, is to attach the vacuum pump to the vacuum chamber. The pump will remove the air from the chamber, allowing us to simulate the vacuum of space. Pumping out the air also has some other benefits from an experimental side; the lack of air in the chamber increases its thermal stability since there’s no longer a medium in which heat can be conducted/convected through the chamber. This means that temperature fluctuations in the lab are unlikely to be felt inside the chamber. A second benefit is air absorbs Lyman-alpha radiation quite strongly, meaning if we left the air inside the chamber the “starlight” would be absorbed before it even hit the surface of our moon.

Monday, November 20, 2017

The Appeal of Space Engineering


This week, undergraduate space engineering student Alexandre Séguin reflects on what he might tell a high school student looking to match up their interests with a career path via a university education. In the spirit of such matching, the image above shows the Jules Verne ATV docking with the international space station (image: http://www.esa.int/Our_Activities/Space_Engineering_Technology/Flight_Safety )

by Alexandre Séguin

As the leaves turn to darker colours and the sun makes its visits shorter by the day, I find myself preparing for yet another end of term examination session. Going over my different courses, I pondered that with nearly two and a half years of progress in York’s space engineering program, I interestingly have had the opportunity to explore quite a few different engineering disciplines. I have had a taste of electrical design, programming, 3D modeling, and orbital mechanics to name but a few. When I recently volunteered at the Ontario University Fair, I took these experiences with me to share them with new prospective students. One of the most common question asked was “Why did you chose space engineering?”. I responded with what I usually say, essentially that I liked math, science, and was good at both. However, now that I have a fair amount of experience as a student of space engineering, I believe the question merits a more thorough answer. In a time where apps and silicon chips rule supreme, what is the appeal to study space engineering?

Wednesday, November 15, 2017

Approaching a Defence in the Lab

The first of our current crop of 5 MScs from 2016 will be defending his thesis in December. This post captures Eric's thoughts as he approaches this milestone and ponders his contributions to planetary science.  While any one thesis is incremental, it is undoubtedly an advance; a stone placed atop what came before that raises the island of science higher.

by Eric Shear

It’s the time of year where I reflect on my research and how far I’ve come. The first draft of my thesis is due at the end of this week, so it’s crunch time for me. This particular project reminds me that science is not all breakthroughs. It’s more usually a series of partial successes and dead ends. It is these roadblocks that help us more, by showing us what doesn’t work. In either case, I must document my research. Perhaps someone else will build on what I’ve learned to build a better spacecraft camera.

Since my last post about using LCDs to increase contrast in spacecraft cameras, I’ve made a great deal of progress. I’ve taken over 90 images of the sun with clouds present in the field of view (but not obscuring the sun). Each image was with at least one LCD, and two-thirds of them were with two LCDs in the optical path. All images were taken with the same exposure time and gain.

The biggest difference I’ve noticed is that the sun is so much more powerful than a mere table lamp, that its rays effortlessly penetrate the darkened patches in the LCDs with little attenuation. Take a look at the trio of photos at the top of this post. At left is the photo taken with one LCD filter, unactivated. At center is the same photo taken with two LCD filters, one activated so the circular block-image is visible. At right is both filters activated with both block-images overlapping to attenuate as much light as possible. There isn’t much of a difference between the centre and right photos.