Friday, February 10, 2023

The Next Generation of New Frontiers Exploration

NASA has several different space mission classes for exploring our solar system. These are arranged by funding level as well as by how quickly they can respond to new science. Discovery provides the least funding but is meant to respond to discoveries that may not have even been made at this point. The medium class, New Frontiers, consists of a list of exciting destinations set out in the planetary decadal survey, the latest of which was just completed last year. The largest missions are run directly by NASA and respond to deep and meaningful science questions that cannot be addressed under the other classifications.
Image caption: The four members of the New Frontiers family: The New Horizons mission to Pluto and beyond, the Juno mission to Jupiter, the OSIRIS-REx mission to Bennu, and the Dragonfly mission to Titan. In the next few years, they will be joined by a fifth member that currently only exists as an idea on paper. (NASA/JHUAPL/SwRI/GFSC)

By Conor Hayes

As a planetary scientist, proposals for new missions to explore the the Solar System are understandably  quite exciting to me, and I’ve recently become interested in understanding how those proposals are prepared and selected. This January, NASA released the draft Announcement of Opportunity (AO) for New Frontiers 5, the first major AO of my time as a graduate student. Although the final AO is not expected to be released until November, this is an excellent opportunity to take a look at what missions we will expect to be proposed over the next year or so.

New Frontiers (NF) is the middle tier of NASA’s three-tier Solar System exploration program, sitting between the low-cost Discovery Program and the flagship Large Strategic Science Missions Program. As the NF5 name suggests, there have been four previous NF missions: three that are ongoing (New Horizons, Juno, and OSIRIS-REx), and one under development for launch in 2027 (Dragonfly).  The mission selected in NF5 must be launch-ready by no later than the end of 2034. 

The science objectives laid out in the NF5 AO can be traced back to the 2013-22 Planetary Science Decadal Survey. The Decadal Survey is a document created every ten years through a collaborative effort of the planetary science community that outlines the highest-priority goals for the next decade. These priorities inform the selection criteria at all three mission levels, depending on what is felt can be accomplished with those levels’ respective budget caps. NASA aims to release two NF AOs for each Decadal Survey but has fallen short of that cadence in recent years, hence why the NF5 AO was released after the completion of the 2023-32 Decadal Survey despite being the second NF AO of the 2013-22 Decadal Survey. 

So what are the science objectives of the NF5 AO? There are six mission themes, each of which has its own list of objectives. To be selected, a mission proposal must address a “proponderance of the science objectives” listed for at least one of the themes. The AO specifies that its use of “proponderance” rather than “majority” is meant to reflect the fact that not all of the listed objectives are of equal importance. A successful proposal could target a small number of high-importance objectives or a large number of low-importance objectives.

The mission themes are as follows, with a brief explanation of some of the key objectives:

Comet Surface Sample Return

In recent years, there have been several missions to return samples from asteroids that were at least partially successful: Hayabusa (Itokawa), Hayabusa2 (Ryugu), and OSIRIS-REx (Bennu). One mission has returned samples from the coma of a comet: Stardust (Wild 2). However, there has not yet been a mission to return samples from the surface of a comet.  Cometary surfaces are interesting as they are rich in volatile organic molecules that have been modified during the comet’s journey through the Solar System. It has been suggested that Earth’s organics may have been delivered through cometary impacts, providing even more motivation to return surface samples. Although some in-situ studies of cometary surfaces have been conducted remotely (most notably Rosetta at 67P), these studies have been necessarily limited by weight and cost considerations that would not be present if samples were returned to be examined in labs on Earth. Organic molecules can be fragile, so it is critical that missions in this theme are able to transport the samples to Earth without destroying  the samples by subjecting them to conditions that would degrade their constituent molecules. A cometary mission should also be able to provide context information about the site the samples were extracted from.

Io Observer

Io is the most volcanically-active body in the Solar System, and missions in this theme will be focused on understanding why that is the case. From my reading of the objectives, an Io Observer has the widest range of science to choose from, and it is unlikely that any proposal would be able to cover them all. Once the mission proposals are finalized, it will be interesting to compare how different proposals in this theme prioritize the science to be returned. These could include determining what fraction of Io’s mantle is molten versus solid, examining the tidal heating mechanisms that are suspected to drive the volcanism, looking for potential tectonic activity, and studying the interactions between the materials ejected from Io’s volcanos and Jupiter’s extremely strong magnetic field.

Lunar Geophysical Network

The goal of missions in this theme should be to examine the Moon’s interior. This could include studying its minerology and composition, as well as its interior heat flow and the distribution and origins of the radioactive isotopes that create that heat flow. To more fully understand the Moon’s interior structure, I would expect to see proposals similar to the InSight lander, which probed the interior of Mars through seismometry. Although the Moon, like Mars, is geologically dead, it experiences Moonquakes like the Marsquakes measured by InSight. The most interesting part of this theme (at least to me) is the “network” in its name. Although none of the science objectives explicitly require it, the name suggests the deployment of several spacecraft across the Moon’s surface conducting coordinated observations. With multiple stations in place, such a system would not face the same kinds of challenges that InSight did operating as a solo seismometer. 

Lunar South Pole-Aiken Basin Sample Return

The South Pole-Aiken Basin is one of the largest impact structures in the Solar System, measuring approximately 2,500 km across and 6-8 km deep. It is also the oldest known lunar basin, having formed less than 500 million years after the Moon itself. Consequently, there is interest in understanding its geology as doing so would contribute to our knowledge of the processes that formed the inner Solar System by constraining the specific timing of the Late Heavy Bombardment. Key objectives include providing in-situ validation of remote sensing data, determining the sources of the radioactive isotopes that contribute to the Moon’s internal heat, and comparing the properties of basaltic rock samples returned from the basin with those returned by the Apollo and Luna missions. In addition to returning samples to Earth, a mission in this theme should also provide geologic documentation of the sampling site.

Ocean Worlds (Enceladus)

Although Jupiter’s moon Europa loves to take all of the media attention for its potential subsurface ocean, it is not the only moon that may be hiding liquid water beneath its thick, icy crust. Saturn’s moon Enceladus is particularly interesting due to the presence of over 100 geysers near its south pole that spray massive plumes of water vapor and other volatiles at velocities sufficient to escape Enceladus’ gravitational influence and enter orbit around Saturn. Exploration of these plumes is a priority because they provide us with an opportunity to examine the contents of the potential subsurface ocean without having to drill through the crust. The goals of such a mission would be to determine if the ocean is potentially habitable and, if it is, whether or not life currently exists within it.

 Saturn Probe

Although Cassini orbited Saturn for over 13 years, it did not include an atmospheric entry probe to perform in-situ measurements of the Saturnian atmosphere like Galileo did at Jupiter. A Saturn probe mission would rectify this by launching at least one probe into the atmosphere with the goal of studying both its physical structure and its elemental composition.


Is there one mission theme that is more likely to succeed than any of the others? At this point, it’s difficult to say, given that no missions have been proposed. Although it may be my own bias as someone who studies the Moon speaking, I would guess that either of the lunar missions might have a slight leg up over the other themes, just considering the fact that you can do a lot more science by sending $900M to the Moon rather than the outer Solar System. The target date for proposal submission is currently April 2024, with initial Step-1 selections announced by the end of 2024, so the shape of the playing field will become much clearer over the next year.

Monday, January 23, 2023

My Summer Trip to MARS

This past summer, PVL PhD student Alex Innanen traveled up to the high arctic (on an expedition led by Prof. Haley Sapers) to test an instrument called MAGE which may someday fly to Mars. Ironically, the name of the research base at which they were stationed is itself named MARS! Given the harsh conditions, the name is perhaps merited and many space agencies use this area to test out technologies they hope to use in exploration activities. (Image above: MARS as seen from up on Gypsum Hill. You can see the edge of Colour Lake below, and Wolf Mountain rising above the ridge, with Crown Glacier beside it.)

by Alex Innanen

As part of my PhD work, I have been working with an instrument called MAGE (the Mars Atmospheric Gas Evolution experiment), which is intended to study trace gases in the martian atmosphere (including methane). The instrument is an off-axis spectrometer, which I won’t get into detail about here, but it is able to measure very small amounts of and changes in methane and other trace gases.

In July, I was lucky enough to be able to take a version of the instrument up to Nunavut for testing – specifically to Umingmat Nunaat (ᐅᒥᖕᒪᑦ ᓄᓈᑦ), or Axel Heiberg Island, where the McGill Arctic Research Station (MARS) is located. MARS is at 79° N and change, which is not quite as far north as you can go in Canada but is pretty darn close. There were three of us going up: myself, Haley, and Calvin, a grad student from CalTech. Up north, we were joined by two grad students from McGill, whose group was then amalgamated with ours.

The reason for going so far away to test the instrument is because of two sites near MARS that are potential martian analogues – Lost Hammer and Gypsum Hill. Both are hypersaline (very salty) cold springs, which are home to methane seeps. The polar desert also has lots of polygonal terrain, which is formed from the freeze-thaw cycle in the ground and has also been seen on Mars. Polygonal terrain can also show interesting methane dynamics, with the troughs acting as a source of methane and the centre of the polygon acting as a sink. 

Polygonal terrain on Umingmat Nunaat seen from the air. 

But before we could get to taking measurements and making sure the instrument worked in such a remote location, we had to get there. The first leg of our journey was from Toronto to Ottawa, from where our flight would leave. We spent a couple days in Ottawa doing last minute shopping and packing and repacking out many coolers and bags of equipment and food. We had to bring not only the personal things we would need for around three weeks in the north, but also all the scientific equipment for the MAGE experiment and biological sampling that would also be done, and food to last us for our time at MARS. Altogether we had nine pieces of luggage, most of which was oversized by the airline’s standards, as well as a 40-50 L backpack apiece.

From Ottawa, we took the Canadian North airline up to Iqaluit. Iqaluit is already above the tree line and, having never been in the arctic, as soon as we set down I was blown away by the landscape, which is absolutely unlike any other place I’ve ever been. We had three hours in Iqaluit, so we left the airport to do a little looking around before it was time to get on a (smaller) plane to our next stop,
Mittimatalik (ᒥᑦᑎᒪᑕᓕᒃ, Pond Inlet). We had a brief stop there, then a quick hop to Ikpiarjuk (ᐃᒃᐱᐊᕐᔪᒃ, Arctic Bay), and then finally on to Qausuittuq (ᖃᐅᓱᐃᑦᑐᖅ, Resolute). This is where the Polar Continental Shelf Program (PCSP) has a base, and from where we would be flying out to MARS. 

The plan was to spend a few days at PCSP before flying to MARS. However, this plan was quickly derailed by the weather. It was a very wet year, and aside from us, many other teams had not been able to get to their field sites because of a combination of fog, thunderstorms, and, at MARS, an inability to land the small twin otter planes because the ground was too wet. Being stuck at PCSP was not the worst thing in the world. We got to meet lots of other scientists and learn about what they were up to, go for many hikes and appreciate the beautiful arctic landscape, and pack and repack and prepare for when we eventually were able to go to MARS.

Our field team in front of the Twin Otter that took us to and from MARS. From left to right: Calvin, Haley, Louis-Jaques, Scott and Me. 

On July 13, 10 days after we got to PCSP, it finally happened. The fog had finally lifted enough for us to get out, and while the ground was still too soggy to land right at MARS, we were able to land a few kilometers down Expedition Fjord. From there, us and our piles of equipment were ferried up to MARS by helicopter. The helicopters were a very special part of our time at MARS. We had originally planned to have only one helicopter day to take us to Lost Hammer, which is one Fjord south of Expedition. However due to the problems with the twin otter flights and other factors, we ended up having a helicopter at MARS nearly the entirety of our trip. Between us and another group we also had plenty of pilot hours, so we were able to make not only multiple trips to Lost Hammer but also to Crown Glacier and the much nearer Gypsum Hill springs (which are within walking distance, but when you’re bringing a bunch of equipment with you it’s nice to get a lift).

MAGE near the foot of Crown Glacier.

MARS is on one side of Gypsum Hill, overlooking Colour Lake and a view down Expedition Fjord. Once again I was absolutely blown away by the beauty, especially since when we landed the sun had peaked out of the clouds on its way around the sky. Like Qausuittuq, Umingmat Nunaat is a type of region known as a ‘polar desert’, but it didn’t seem like it. Not only was the tundra soggy from so much unseasonal rain, but it was carpeted with all kinds of artic plants – saxifrage, arctic poppies and even a kind of tree, the arctic willow, which instead of growing upwards sends its branches along the ground. As I was taking measurements with the MAGE instrument in the camp, a bee buzzed past me, and I was surprised to see something that looked like a butterfly. It was a butterfly! One of the great parts of staying somewhere with so many scientists is you get to learn about their areas of expertise, and there was an entomologist at MARS who told us all about the kinds of insects we might see. 

The major goal for the MAGE instrument was to be able to bring it up to almost 80° N and turn it on – success! More success followed, and I managed to get readings at MARS, the two spring sites, the polygonal terrain near MARS and at the foot of Crown Glacier. I had a lot of fun figuring out where to put the instrument, how to best run it with its power limitations, and what might make an interesting set of readings. Not only did the instrument successfully collect data on methane abundance, but we also figured out how we might be able to improve the instrument and the data we collected. For instance, I was measuring wind direction by holding up a roll of flagging tape and seeing which way the dangling end blew. An anemometer would let us get much more detailed information about how the wind effects our methane measurements.

The MAGE instrument taking measurements with Lost Hammer spring in the background. The white cone-like mound is made of Gypsum, with the spring hiding inside.

Before I left for the trip, I was extremely nervous, not only because I had never undertaken field work like this before, but also because I’d be spending nearly three weeks in one of the most remote parts of the world and had no idea what to expect. But from the moment I set foot in Nunavut I knew I’d made the right choice to go. There were still difficulties, like when it seemed like we might never make it to MARS, or getting frustrated with the limitations of the instrument, but taken altogether not only did MAGE preform admirably but doing fieldwork helped me discover and strengthen skills I didn’t know I had. I’m so grateful to have had this experience.

Tuesday, December 6, 2022

Hitching a Ride to the Moon (and Beyond!)

 Above, a series of ten 6-U cubesats can be seen attached to the ring which interfaces between the top of the Space Launch System (SLS) rocket and the payload fairing. It's not unusual these days for spacecraft to use extra mass allowances for these sorts of ride-along launches. It would be very difficult to arrange a special launch just for those spacecraft, so these larger launches provide a vehicle to considerably increase the science return from a space launch and to provide access to (deep) space to others. Here at PVL, we're very excited about the coming small-space era in Planetary Science!

By Conor Hayes

The launch of Artemis I on November 16, 2022 was a highly-publicized event, and for good reason. It has been 50 years since the last time we left the Moon, and although the first crewed landing of the Artemis program is not expected to take place until 2025, Artemis I is still an exciting step towards our return to the Moon.

Much less well-advertised was the fact that the Orion Multi-Purpose Crew Vehicle was not the only spacecraft riding the SLS rocket to space that night. Accompanying Orion were ten CubeSat microsatellites. The CubeSat standard was established in 1999 and has primarily been used for technology demonstrations and other missions whose higher risks make larger, more expensive satellites challenging to justify. Of course, this means that CubeSats are almost never launched on their own, instead needing to hitch a ride along with some other mission.

The ten CubeSats launched along with Artemis I were all in a 6U configuration, meaning that they each consisted of six CubeSat “units” joined together. A CubeSat unit is a box approximately ten centimetres along each edge with a mass of no more than two kilograms. This extremely small volume means that CubeSats have a very limited ability to propel themselves, so they are typically launched along with a mission that has the same target object. In the case for the Artemis CubeSats, this means that five of the ten microsatellites are aiming for the Moon as well.

So, what were the ten CubeSats that Artemis I carried into space?

ArgoMoon is a collaboration between the Italian Space Agency and Argotec, an Italian aerospace engineering company. Its primary mission is to take images of the Interim Cryogenic Propulsion Stage – where all of the CubeSats are stored – and to confirm that the other CubeSats successfully deploy. This mission will demonstrate the ability to use a microsatellite to autonomously inspect and maneuver around another spacecraft. Once deployment of the other CubeSats is complete, ArgoMoon will test the resiliency of its communications equipment in the harsh radiation environment outside of Earth’s magnetic field.

The BioSentinel CubeSat mission was created by NASA Ames to examine the effects on DNA of long-term exposure to the deep space radiation environment. This is critically important information to have as we prepare for extended missions to the Moon and Mars so that we can develop methods of mitigating DNA damage to reduce the likelihood of astronauts developing various cancers and other threats to their health. BioSentinel will use two different strains of yeast as an analogue for human cells. The health of the yeast cells during the 18 month mission will be assessed by monitoring their growth and metabolic activity and comparing it to the radiation doses measured by sensors onboard the spacecraft. The results will then be compared to three identical copies of the BioSentinel experiment, one of which will be exposed to the low Earth orbit radiation environment onboard the International Space Station.

The CubeSat for Solar Particles (CuSP) is a technology demonstration mission developed by the Southwest Research Institute. It contains three science instruments designed to count the number of energetic particles ejected by the Sun, as well as to measure the strength and direction of the interplanetary solar magnetic field. If all goes well, CuSP could justify the creation of a fleet of similar small satellites positioned throughout the Solar System to form a space weather monitoring system. 

The EQUilibriUm Lunar-Earth point 6U Spacecraft (EQUULEUS) is one of two Artemis CubeSats provided by the Japan Aerospace Exploration Agency (JAXA). Despite its small size, much science has been packed into it. EQUULEUS carries three science instruments as well as an experimental propulsion system. Two of the instruments are designed to detect the presence of dust and micro-asteroids in the space between Earth and the Moon, while the third will characterize the near-Earth plasma environment. Rather than traditional rocket fuel-powered propulsion, EQUULEUS will use water thrusters to propel itself into a halo orbit at the Earth-Moon L2 Lagrangian point and to fly-by any micro-asteroids that it discovers.

The Lunar Polar Hydrogen Mapper (LunaH-Map) was provided by Arizona State University to map water ice at the Moon’s poles. It will use a neutron spectrometer to measure the flux of high-energy neutrons leaving the lunar surface. These neutrons are suppressed by the presence of hydrogen atoms, so areas where LunaH-Map measures fewer neutrons are likely enhanced in hydrogen-bearing molecules like water. This mission will build on results from the Lunar Exploration Neutron Detector (LEND) onboard the Lunar Reconnaissance Orbiter (LRO), building higher-resolution maps thanks to its lower-altitude orbit (5 km for LunaH-Map versus 20 km for LRO). Unfortunately, the satellite experienced a problem with its propulsion system shortly after deployment, meaning that it was unable to insert itself into lunar orbit. However, there are still several months left to diagnose the problem before its current trajectory will make the mission unrecoverable. If the LunaH-Map is able to diagnose and fix the problem and get the spacecraft into orbit, the mission is planned to last for 96 days, after which it will be launched into a polar crater. 

Lunar IceCube
As its name suggests, Lunar IceCube is another mission to search for ice on the Moon, developed by Morehead State University in collaboration with the Busek Company, the Catholic University of America, and NASA Goddard. It will hunt for water ice and other volatile molecules at the Moon’s poles from a 100 km orbit using an infrared spectrometer. 

LunIR (formerly known as SkyFire), designed by Lockheed Martin Space, is another lunar mapping mission. Its primary mission objective is to test a low-cost thermal imager that could be used to characterize future landing sites on the Moon and Mars. It will also test the use of an electrospray thruster, in which electrically-charged liquid is expelled to provide thrust, for small orbital adjustments. The LunIR team have not provided updates on the spacecraft’s status post-launch, so it is currently unclear whether or not it is operating as expected. 

NEA Scout
The Near-Earth Asteroid Scout (NEA Scout) is a NASA mission that will use a solar sail to propel itself to 2020 GE, a near-Earth asteroid approximately 18 metres across. Because it is extremely difficult to identify and track objects of this size, not much is known about them, leaving a critical gap in planetary protection plans. This mission carries a single instrument – a camera that will be used to take high-resolution imagery of 2020 GE. Unfortunately, NEA Scout failed to make contact with the Deep Space Network after deployment, so the team is currently attempting to recover the spacecraft.

The Outstanding MOon exploration TEchnologies demonstrated by NAno Semi-Hard Impactor (OMOTENASHI; some very creative acronym work!) is the second of JAXA’s contributions to the Artemis I CubeSat collection. It was designed to be a semi-hard lunar lander, using a combination of rockets and airbags to impact the lunar surface at 20–30 m/s. It would then use an onboard radiation detector to study the radiation environment at the surface. Shortly after deployment, communication with OMOTENASHI was lost. After five days of recovery efforts, the team concluded that the spacecraft’s solar panels had failed to find the Sun, leading to an unrecoverable shutdown of the spacecraft following battery depletion.

Team Miles
The final of the ten CubeSats is Team Miles, a technology demonstration mission by Fluid and Reason, LLC. Team Miles was developed to test new propulsion and communications technologies. It will fly past the Moon towards Mars, with a goal to travel at least four million km and possibly up to 96 million km.
These will certainly not be the last CubeSats launched towards the Moon as we enter the Artemis era of lunar exploration. Indeed, there are already three more prepared for launch that just missed the Artemis I integration deadline: Cislunar Explorers, Earth Escape Explorer, and Lunar Flashlight. Although they may not nearly be as flashy as larger missions like the main Artemis flights, the proliferation of microsatellites has provided excellent opportunities for groups with less available funding to get good science done without having to compete for space onboard a more expensive mission, making off-Earth research more accessible for everyone.

Sunday, November 20, 2022

What’s going on with methane on Mars?

This week, Madeline discusses a critical component of her research into how methane is vertically distributed in the martian atmosphere. Read on for some details about the present state of the ongoing debate about Methane on Mars.
(Image source:

by Madeline Walters

On Earth, we’ve often heard of methane being produced as a result of living beings-microbes that help with livestock digestion. Though when we found methane on Mars, we were puzzled by its origins. Are there microbes helping the digestion of Martian cattle? Most signs point to no, however, we are still unsure of what may be producing the gas on Mars. Besides biogenic sources, methane can also be produced by geological processes, so being able to identify the sources of methane is a tricky yet interesting problem.

The issue with identifying the sources of methane is finding the methane in the first place. Since landing in Gale Crater in 2012, the Tunable Laser Spectrometer (TLS) instrument onboard NASA’s Curiosity rover detected background levels and a few higher spikes of methane from the surface, however, ESA’s ExoMars Trace Gas Orbiter (TGO) wasn’t able to detect any methane from higher up in the sunlit atmosphere. 

TLS lead scientist Chris Webster [1] comments: "When the Trace Gas Orbiter came on board in 2016, I was fully expecting the orbiter team to report that there's a small amount of methane everywhere on Mars, but when the European team announced that it saw no methane, I was definitely shocked.

The results were certainly unexpected after other detections of methane from other instruments, leading to new questions about whether the detections from TLS perhaps originated from the rover itself. Some scientists suggested the rover detected methane after crushing rocks, or perhaps wheel degradation, not willing to rule out any possibilities. However, the Planetary Fourier Spectrometer onboard the Mars Express (MEx) spacecraft observed higher levels of methane in 2013, after Curiosity also reported a methane spike, bringing back the question of how to make sense of these detections.

So why are some instruments reporting methane while others aren’t? This is something that is puzzling scientists almost as much as the source of the gas itself. Because of the conflicting reports of detection from different instruments, the key is observing how methane diffuses through the atmosphere at different times of day and through different seasons to see if perhaps the reports of methane from different instruments can still make sense.

Moores et al. [2] suggests a small amount of methane seeps out of the ground continuously such that during the day, it mixes well with the atmosphere, which results in very low levels of methane further up. Meanwhile at night, the methane can build up near the surface from the lack of convection. From this approach, we can make sense of both the ExoMars and Curiosity observations. While this could explain the discrepancies in methane detection from different instruments, we still have yet to determine the origin of the gas itself and if that origin perhaps can explain how the gas is being destroyed much quicker than it should. Because solar radiation and oxidation should be destroying the produced methane after a lengthy 300 years, the excess methane buildup should be detectable by TGO. This points to some destruction or sequestration mechanism that is getting rid of the methane quicker than expected such that the detected amounts make sense. 

"We need to determine whether there's a faster destruction mechanism than normal to fully reconcile the data sets from the rover and the orbiter," says Webster. 

One possible explanation for this is the gas’ reaction with the surface components. A chemical compound called perchlorate, which has been detected by Mars landers, may be acting as a sink for methane due to oxidation reactions [3]. When exposed to ultraviolet radiation from the sun, perchlorate accelerates the destruction of methane-from over 300 years to just days or hours. However, scientists are still exploring this possibility and as of right now, there’s still no way to be sure this is the reaction responsible for the gas’ quick destruction. While there are still many questions surrounding Martian methane, we are getting closer to explaining the mysteries of the gas.



[1] -methane-mystery
[2] Moores, J. E., King, P. L., Smith, C. L., Martinez, G. M., Newman, C. E., Guzewich, S. D., et al. (2019). The methane diurnal variation and microseepage flux at Gale crater, Mars as constrained by the ExoMars Trace Gas Orbiter and Curiosity observations. Geophysical Research Letters, 46, 9430– 9438.

[3] Zhang, Xu & Berkinsky, David & Markus, Charles & Chitturi, Sathya & Grieman, Fred & Okumura, Mitchio & Luo, Yangcheng & Yung, Yuk & Sander, Stanley. (2021). Reaction of Methane and UV-activated Perchlorate: Relevance to Heterogeneous Loss of Methane in the Atmosphere of Mars. Icarus. 376. 114832.

Tuesday, November 1, 2022

More conference talk. Suddenly stuck at home? Make the best of it!

We had all hoped to be in person at this year's DPS, however, the hybrid nature of the conference meant that any students who had last minute disruptions could still attend virtually. It's really nice to be able to accommodate these sorts of situations and, while the online experience is not the same as the in-person experience, it means that someone who has made arrangements and already paid their registration can still get some value out of the conference, perhaps even more value than they had expected as our new PhD student Elisa Dong attests below. For more on the picture above, see the Caption at the bottom of the article.

 by Elisa Dong

New PhD student (Elisa) checking in with the usual readers of this blog. This week I've been invited to discuss whatever I so desire on the blog. I happened to be writing something for my own blog on attending conferences. Here are a series of mostly serious tips for attending conferences remotely, when the format is hybrid and all your friends are attending in person. The backdrop for this conference was DPS, on which Conor has recently posted. A lot of these tips have been test-run during the pandemic where I attended AGU online.

Tips for attending a scientific conference (when you're remotely at a hybrid event):
1.     Identify your favourite conference snacks and drinks
2.     Purchase, make, or make student-budget friendly versions of said snacks and drinks
3.     Plan chores that require at most 1 hour of your time. Preferably a bunch of 10-15 minute chores
4.     Acquire bluetooth headphones
5.     Identify some clothes for dressing up (or down)
6.     Pick a few "key" sessions you want to be awake for and some interesting ones to pad out the rest of your time.
7.     Chat with your lab mates on your preferred communication method of choice.

Let's break these down a bit. Say you were really looking forward to attending the conference in person and had already planned for those days to be away. However, you've fallen sick or some event has taken place that prevents you from attending. You might as well try to get part of the conference experience at home! While there will be significantly less mingling with others and networking opportunities will be, at best, awkward and stilted you can still delight in the little snack breaks while reflecting on the state of the field.

This brings us to tip number 1. If you've been to a conference before, what snacks did you enjoy during the breaks? Personally I like that there are usually several tea options, and sometimes the coffee is palatable. The previous conference I had attended online (planned), I had the time to order some coffee samples and pick up a variety of snacks from the asian supermarket. This time I was stuck in quarantine, so I made sure I had a kettle and a massive stock of tea bags. This covers tip number 2 as well. It doesn't have to be fancy, but having the ability to make hot drinks on demand is quite nice. It's reminiscent of downing drinks to soothe your throat in the dry, conference room air.

Tip number 3 and 4 involve keeping yourself busy. Unlike an in-person conference, there are very few things you can look at that you are unfamiliar with. You likely won't have access to the attendees (no camera facing that way, zoom only shows the speakers) so figuring out who else is at that session is out unless they speak up during Q&A. Instead, you could be getting some mundane tasks done! I personally can't look at a screen continuously, so laundry, cleaning the kitchen, organizing bookshelves, watering/trimming plants, etc. all give me breaks away from the screen, but I'm not doing anything so critical that I can't check what's on the screen if it's particularly important. Tip 4 gives you the flexibility to move around without fear of wires tangling or blasting the audio (less of an issue if you don't have roommates, but still a nice option). Earphones are also an option, but I find headphones to be a bit better with universal fitting. Also, you now have the wonderful ability to choose to go to the bathroom while still listening to the sessions.

It's all good to be perfectly cozy while stuck at home (or if you're so inclined, going outside while still plugged into the conference). A big part of the conference experience is being present though. For me, that means dressing in a slightly snappier manner than I normally might. Regardless, I would want to have a change of pace for "conference time", much like when working from home, it's helpful for me to dress up for "work hours". Dressing down could be a fun alternative to this though. After all, no one can see that you're in the goofiest of onesies. Similarly, no one will know (other than your housemates) that you attended in a full ballgown and mask. So that's tip 5.

Tip 6 is applicable to any conference you attend. There is only so much time in a day, so pick your favourite events to go to. Figure out what's relevant to your interests. Not much more to say about this one. Tip 7 is similarly applicable always. Should you find yourself longing for some company, or wanting to experience the social aspect of the conference, checking in with your lab mates or anyone else at the conference can be nice. If you're all together (remote or in person), it can be nice to schedule some hangout time outside of the planned events.

Lastly, it's always a good idea to tap out whenever you're feeling tired. No point attending a conference in your brain is on the fritz. A copy of these tips can be found on my personal blog (soon),, where I will likely keep posting silly little pseudo-articles on science and whatever catches my interest at the time.


As an aside, for all potential incoming grads, here are the things that have happened in the last 2 months:
-        started taking my singular mandatory course (yay for transfer credits!)
-        met up the rest of the lab at an outdoors event and found out we're all equally bad at playing frisbee
-        confirmed that housing is as tricky as I thought it would be
-        ran into an old friend at the university!
-        had an impromptu zoom call with the founder of a company whose instruments I'm hoping to use in the near future (no spoilers!)
-        learned how to plug things into a breadboard and string things together with different communication protocols
-        moved some plants into the office, including my favourite "it's time to go home plant" (Fig. 1)

Figure 1 Caption. Here is my plant before I moved it to the office. The "it's time to go home plant" is an Oxalis triangularis. This purplish plant has a few relatives, but they are also referred to as "false shamrocks" when they are of the green variety. The sets of three leaves close up when the light begins to dim. This is usually my sign that I've been at work for too long during the summer months, and a reminder to start packing up during winter. I have been tricked in the past, as the leaves remain open with artificial lighting as well. They're generally pretty happy office/house plants, require moderate temperatures, nothing special in terms of humidity, and enjoy filtered light. They do grow rapidly outdoors, so don't plant them outside!

Wednesday, October 19, 2022

Completing the Thesis Defence: The Final Boss of a Graduate Degree

This past summer, several of the students in PVL had the opportunity to go through the timeless ritual that all us academics undergo in order to earn our MSc and PhD degrees: the oral defense of our research. I can report that everyone made it through with flying colours! Of course, a defence is also a transition for the student who may be moving from an MSc into a PhD, from a PhD into a Postdoc or from their MSc into the working world, amongst other paths. If you are considering getting a higher degree and want to know what this hurdle looks like, or are starting to think about your own defense, Grace has some helpful insight below. 
(Image above from XKCD Comics:

 by Grace Bischof

The end of the summer marked a busy time in the Planetary Volatiles Lab. Conor, Giang and I were each nervously preparing for our upcoming thesis defences, where we would learn if we were to pass and obtain our degrees, or fail and be very, very sad. Giang, reaching the end of his PhD in August, defended first, setting the tone for the rest of us by passing! Conor and I followed, defending on September 7th and 8th (apologies to our shared committee members who had to sit in back-to-back defences). Conor and I were also successful in defending our theses, meaning we both obtained our master’s degrees. It was a very exciting end to the summer.

So, what is a thesis defence and why is it so nerve-wracking? In a research-based degree, the findings of the research you complete over several years get written up into a document – at York, this is a thesis for a master’s and a dissertation for a PhD, which is a more robust document than a thesis. This document represents years of hard work, and hopefully, makes an original contribution to the field in which you’re studying. That, in and of itself, is a nerve-wracking process. But before the university can award you your degree for all the painstaking effort you have put into your thesis, they first must test you on the contents in the form of an oral examination.

The oral examination usually begins with a public talk, where your research is presented in a 20 minute to hour long (depending on the degree) presentation. Typically, anyone can join this portion of the defence, and for me, it was fun having my friends and family watch my presentation so they could finally stop asking what it is I actually work on. Once the public talk is over, everyone else leaves the room, so it is just you and your committee. One-by-one, the committee members take turns dissecting your thesis, asking questions, and making suggestions about the contents to facilitate discussion on your work. This process can last several hours, especially for a PhD defence which is more involved. Once the committee has run out of questions to ask, you are kicked out of the room while they deliberate. Sitting outside the room while a small number of people decide the fate on the culmination of your work is horrifying. Then you are finally called back to the room to receive to your verdict…

The good news: the thesis defence is largely a formality. That is, if your research supervisor is doing their job, you will not walk into the thesis defence if you are not going to pass. The purpose of the defence is simply to ensure the student understands their work and the literature in which it is situated. Not knowing the answer to an examiner’s question does not mean you will fail the defence. In fact, the examiners want to see you reason through their questions, applying your knowledge even when you do not have the exact answer. There was one point in my defence when I answered a question completely incorrectly but realized my error once I thought more about it. I told the committee that the answer I gave was incorrect and walked them through my thought process to answer the question correctly. The committee was more interested in seeing my reasoning in getting to the answer than they were worried about the initial mistake I made.

So, now that you know what a thesis defence is, let’s briefly walk through some tips for the defence:

  1. Start preparing early. The amount of time needed to prepare is going to depend on the degree being obtained – i.e., PhD students will likely need to start earlier than master’s student. Three weeks out before my defence I began to seriously prepare. I started by compiling a list of the most important references in my thesis. I read a handful of these a day, highlighting and jotting down notes on important aspects of each paper. At this time, I was also walking through the basics of the field – sure, it might impress your committee to describe in detail all the aspects of radiative transfer in the atmosphere, but that might diminish if you forget Mars is the 4th planet from the sun.

  2. Anticipate questions. About 1.5 weeks from the defence date, I began combing through my thesis line by line. I had a PDF version of my thesis which I used to highlight and make notes in the margins. I wrote down anything that came to mind when reading my work and how the committee might interpret it. Some common questions that are asked in defences are: “How does your work fit into the existing literature”; “Describe your work in a few short questions”; “In what ways can this work be expanded?”; “What limitations did you experience in this work?”. Funnily enough, I prepared for all these questions and did not get asked any of them. However, preparing for them helped me to pick apart my work more carefully, meaning I could answer the questions they did give me.

  3. Try to relax as much as possible. It’s easier said than done. An important tip that I read online before defending my thesis was to make sure that in your state of nervousness, you don’t consistently interrupt the examiners while they are asking questions in an attempt to quickly prove you know the answer. When an examiner is speaking, it’s a perfect time to collect your thoughts and let them talk (it eats up more time this way too!). But, like I said, the defence is largely a formality. If you’ve done the work, then you know your stuff and you will crush it! You are allowed to sit and think about your answer before speaking, drink some water or have a snack, and take a break during the defence if needed. After the first 30 minutes of the defence, the rest breezes by.

Your thesis defence will probably be the only time you will ever have a discussion with people who have ever read the full contents of your thesis. That itself is a pretty cool opportunity, so try to enjoy it as much as you can! Hopefully in four years’ time, when I’m preparing for my PhD defence, I can come back to this blog post and try to take my own advice.  

Sunday, October 16, 2022

PVL in London (Ontario, That Is)


This week, new PVL PhD student (formerly PVL MSc student - congrats!) Conor Hayes reflects on the just completed DPS Conference that they attended a few weeks ago. This is the first time that DPS has been in person since Geneva, Switzerland in 2019 and the first time it has ever been held in Canada. I certainly appreciated being able to experience the conference together with my graduate students as a research group without even having to bring my passport!

by Conor Hayes

It has been nearly a year since I last submitted an entry to this blog, detailing my experience at GAC-MAC 2021, my first in-person conference as a grad student. Much has happened since then; I half-pivoted away from the Moon to add a new MSL-based project to my Master's thesis less than nine months before my defence, I wrote and successfully defended said thesis, and now I'm a freshly-minted PhD student here at PVL.

Some things, however, do not change, so I am here once again to talk about our latest conference experience at the 54th Annual Meeting of the Division for Planetary Sciences (DPS). PVL typically puts up a strong showing at DPS because we are all planetary scientists, and this was particularly true this year for two reasons. First, DPS 54 was held in London Ontario, practically down the road (relatively speaking) from us here at York. Second, PVL’s own John Moores was Chair of the Science Organizing Committee, so we couldn’t not represent our group well.

In many ways, DPS was very similar to the two in-person conferences that I was able to attend during my Master’s – GAC-MAC back in November of last year, and the 7th Mars Atmosphere Modelling and Observations conference this summer. The scientific program was divided between oral talks and poster presentations, with a plenary session in the middle of each day. I mostly stuck to the sessions on topics that I’m interested in – the Moon, Mars, and terrestrial planets, though I did attend a few that were more “out there” (at least with reference to my own research) on Europa and other icy moons, as well as sessions on citizen science, education, and public outreach.

Although it followed this familiar pattern, DPS was very much a conference of firsts for me. Because DPS was a hybrid conference this year, each session had two chairs, at least one of whom had to be in-person. One chair would make sure that each speaker stuck to their allotted time and manage questions from in the room, while the other would monitor the session’s Slack channel, where virtual attendees could ask their questions. Due to the continually evolving health situation, there were a number of in-person chairs who had to switch to virtual attendance, meaning that some sessions no longer had an in-person chair. Several members of PVL (including myself) were recruited to take their place. The session that I chaired was titled “Dynamical Dances in Space,” and featured four talks discussing gravitational interactions between various Solar System bodies, the first of which was actually based on a newly-published paper that I had read shortly before the conference. Stepping in as chair at the last minute was a little daunting because I had no idea what to expect, but it ended up being a reasonably non-stressful affair.

Much more stressful was the fact that this was the first time that I had been invited to give an oral presentation at a “major” conference. I’ve given presentations about my research before, but always in much lower-stakes settings, whether that be in PVL group meetings or at smaller conferences run by graduate students (e.g. York’s Physics and Astronomy Graduate Executive conference or the annual Lunar and Small Bodies Graduate Forum). On top of that, I had never presented the preliminary results of my lunar work to a larger group before, so there was a lot that I was worried about. Consequently, I spent a lot of time preparing my presentation and making sure that I stayed as close to the seven minute limit we were given. In the end, the magnitude of my stress was wildly disproportional to the actual event, as my presentation went smoothly and hit the seven minute mark almost exactly. Although I would have happily taken just that as a win, it has also inspired my first official research collaboration with someone outside of PVL, something that I am very excited about.

Now that I’ve had experience with both oral and poster presentations at conferences, I think I can say that I prefer oral presentations over posters. Posters certainly do have their advantages – you present all of your information on a single page and you don’t have to worry about time limits or making sure that you remember what you want to say, as posters often come with a more conversational style of sharing information. However, I’m just not really a fan of the poster experience. During a poster session, you’re sharing a room with many other people presenting their posters at the same time, so there’s a certain element of competing for the attendees’ attention. Some people can also find approaching the presenters one-on-one more intimidating than asking a question at an oral presentation (I certainly do!), which might limit the number of interactions you have. I definitely don’t want to turn people off of poster presentations; they can be a low-stress way to ease your way into the conference experience and/or to present early/preliminary results that are still in progress.

Overall, DPS was probably my favourite conference of the handful that I have attended (either virtually or in-person) over the past two years. I can only hope that the weather in San Antonio will take a break from its usual late-summer Texas heat for DPS next year.