Monday, October 9, 2017

Giang’s Adventures in the Land of Perpetual Grey

Last month, PVL MSc Student Giang left Toronto on the first International Cross-Disciplinary Internship (X-I2) of the TEPS program. In this week's installment he checks in from Oxford University, in the UK. You can find his two "postcard" images above and further down, below the cut.

by Tue Giang Nguyen

The new term has started and as I finish up my work on Mars’ northern polar cap, I head out to start something new in the UK. As a trainee of the Technology for Exo-Planetary Science (TEPS), I have been accepted to an international internship at the university of Oxford. After going through various potential projects such as looking at the ancient Martian atmosphere, it was decided that I will work on thin condensable atmospheres useful for understanding interesting exoplanets like 55 Cancri e or CoRoT-7b. I’ll be working with established Oxford Professor Raymond Pierrehumbert on the project as well as furthering my studies on the Martian polar cap.
This is the first time I’m going to Great Britain, in fact, it’s the first time I’m stepping on European soil (though British people aren’t keen on associating themselves with the rest of Europe these days). Packing for the trip wasn’t problematic as I don’t really have a lot of stuff; I don’t even have an umbrella which I’ve been told is quite necessary for survival in the UK. I was somehow smart enough to remember to buy outlet converters at the airport just before the flight as I can see how it would be quite problematic arriving in England without being able to charge my phone or laptop.

Sunday, October 1, 2017

A Puzzling Moon

This week, Jasmeer Sangha talks about his work extending his simulations to include many different species of planetary volatiles bouncing around on the moon. While water was known to be present, it was LCROSS (depicted above in this artist's concept image from Northrop Grumman) that discovered a wide range of different compounds in the PSRs.
by Jasmeer Sangha
This semester I chose to extend my research past just water molecules and shift focus towards results brought back from LCROSS, the Lunar Crater Observation and Sensing Satellite. The LCROSS mission launched in 2009 and scientists found more than just water on the moon. The mission objective was to have the Centaur, a rocket stage, launch itself into the moon. It was decided that Cabeus, a large crater near the lunar south pole, would be the Centaur’s destination. Cabeus is a permanently shadowed region which allows freezing temperatures to trap particles in a layer a frost.  The debris cloud made by the impact would be analyzed by LCROSS, orbiting up above, to discern the frost's composition. From this experiment, it has been shown that carbon, nitrogen, and sulfur compounds were present in Cabeus, yet water was the dominant constituent, outnumbering all other compounds 5 to 1.
                  Though we know what is in Cabeus crater we are unsure as to how it got there. My previous work focused on the mechanism of traveling water molecules along the surface. The program randomly spawned particles on the surface of the moon and followed there lives until they were trapped in a dark hole for eternity, cooked by the Sun’s rays, or lost to space - what lovely ways to go out, right?  The results would show us how water ice is distributed on the surface. 

Introducing our new Postdoc

Introducing our newest addition to PVL, Dr. Paul Godin who comes to us from the University of Toronto! Paul specialized in laboratory-based research in the atmospheric sciences, and will now apply that strong base to the atmospheres of other worlds. The image above is from the Intergovernmental Panel on Climate Change and depicts IR absorptions both of the atmosphere (top) and of select molecules (bottom).

by Paul Godin

Hello World! My name is Paul and I’m the newest member of the PVL, so I should probably introduce myself, eh? I just completed my PhD in physics at the University of Toronto studying the radiative impacts of several chemicals on the atmosphere, using a metric known as a global warming potential (GWP). A GWP is the measure of the radiative forcing of a pulse emission of one kilogram of gas over a defined period of time (commonly taken to be 100 years), relative to an identical pulse emission of carbon dioxide. Radiative forcing is defined as the net change of radiation at the tropopause; positive radiative forcing means more radiation directed towards the surface (leading to higher surface temperatures), whereas negative radiative forcing corresponds to a net cooling effect.

The radiative forcing of a molecule depends largely on two main factors, the absorption spectrum of the molecule and the absorption profile of the atmosphere. The absorption spectrum of a molecule is a result of the quantum mechanical interactions within the molecule, thus the structure and composition of a molecule will dictate at what wavelengths of light the molecule can absorb. The atmospheric absorption spectrum is the sum of the absorption spectra of all the species present in the atmosphere (largely made up of water, carbon dioxide, ozone, nitrogen, etc.). The atmospheric absorption spectrum for the infrared (wavelengths associated with outgoing radiation) is shown in the top half of the figure at the start of this article. As can be seen, the atmosphere normally absorbs a significant fraction of outgoing radiation, but also has a region where it doesn’t naturally absorb radiation (8-13 μm), which is known as the atmospheric window. This is great for life on Earth; we need to trap some of the radiation to keep the planet from being frozen, but also allows enough heat escape that we don’t turn in to a furnace (i.e. Venus).

Friday, September 15, 2017

Wispy Clouds on Mars!

Normally I use this space to make some "witty" comments to ease you, our readers, into each article. But today I'm going to get out of the way because I just can't say it better than seasoned MSc student Charissa Campbell and her animations: "Here are the beautiful movies taken on sol 1758. On the left is the SHM which shows the Martian landscape with the wispy clouds above. The right is the ZM that is taken directly above the rover but still shows the similar wispy features as the SHM. They are both taken around 7:00 am."

 by Charissa Campbell

One of my roles on the Curiosity Science Team is to process the atmospheric movies taken by the rover. They consist of 8 sequential images of the sky above the rover. There are two kinds: Zenith Movie (ZM) and Supra-Horizon Movie (SHM). The only difference between these two observations is the angle of the camera with respect to the rover. The SHM is taken at an angle of 38.5° elevation, which is right above the crater rim, while the ZM is taken directly above the rover at an angle of 85°. 

Most of these movies are taken either in the early morning or afternoon as studies show that these two periods during the sol are when clouds most likely appear. In fact, there even is a season on Mars that exhibits more clouds than other times of the year. This is known as the Aphelion Cloud Belt (ACB) and starts in the late fall in the southern hemisphere, where Gale Crater is located. It is given this name because it peaks around the Aphelion of Mars; the furthest point that Mars will be in its orbit around the Sun. Clouds can be seen at other times of the Martian year. However, the ACB is a season that distinctively shows clouds. We even use this recurring season to plan atmospheric movies for Curiosity so that we can analyze these clouds in greater detail.

Sunday, September 3, 2017

So you think you can research, Vol. 2

This week Alex Séguin, one of our undergraduate research assistants, recounts his experiences at the Lassonde Undergraduate Research Fair. This year we had two entrants - Alex in the poster competition and Brittney Cooper (who wrote last year's post on this event) in the oral competition where she took first prize. I'm already looking forward to next year's Vol. 3.

by Alex Séguin

On Tuesday, August 15th, the Lassonde School of Engineering hosted the 2017 Summer Research Conference. Affectionately named "So You Think You Can Research?”, the event offered undergraduate students working in Lassonde a chance to present the work they have done over the last four months. Naturally, the vast majority of participants were Lassonde students but some were studying mathematics, biology, psychology, or even came from other universities! As for myself, I presented a poster of my work with PVL titled Towards an Airborne Methane-Measuring Sensor for Titan Exploration.

The day started off with complementary coffee and a welcome address from Dr. Pagiatakis (Associate Dean, Research and Graduate Studies), Dr. Philipps (Interim Vice President Academic and Provost), and Dr. Sinclair (NSERC Ontario Regional Office’s Manager). They emphasized the importance of our first research contributions, saying they are valued and recognized. After this, a newly appointed Assistant Professor named Dr. Boakye-Yiadom talked about his current research, some of the things he had learned along the way, and how they applied to us. In fact, most of what he said applies in any research context!

Wednesday, August 16, 2017

The Landscape Art of Mars

Alexandra Innanen is an Undergraduate Researcher working at PVL for the summer. Along with MSc Giang Nguyen, they've been scouring the Northern Polar Cap of Mars in images, looking at the fine details and trying to deconvolve what role the atmosphere plays in their formation. Along the way, Alexandra has seen more than just thousands of images of dust and ice and had the opportunity (below) to talk a little bit about the aesthetic appreciation of the landscape that one can obtain from orbit. Today she shares with you her top five selections!

By Alexandra Innanen

The North Pole of Mars is a pretty cool place – pun absolutely intended. This summer I’ve joined Giang in looking for patterns in the Martian ice cap, something he talked about in a previous post. I have looked through a truly astronomical number of HiRISE images, nearly 1000 at this point. While many of them do showcase those beautiful patterns we’re looking for (I have been known to punch the air at a particularly uniform set of dunes), a number are what I lovingly refer to as ‘garbage’. Some of these are just flat nothingness, with no distinguishing features to recommend it. Some are more visually interesting, but without any sense or uniformity. These are fairly useless in terms of patterns, but can be fun to look at, and sometimes have neat stories behind them.

I have a folder on my laptop called “Space Stuff” which I could easily rename “Nifty Pictures of Mars” at this point. It’s full of HiRISE images that I looked at and went “well, there’s no pattern there but boy is that cool!” I’m going to show off my top five images here.

Okay, the one at the top of this article is probably the coolest. Should I have ended with it? Is everyone going to leave now? Anyway, this is an avalanche at the edge of the layered deposits of the north pole, which fall off in steep cliffs (reminding me a bit of the Scarborough Bluffs near where I live). You can see the layering in the escarpment, and the edge of the ice in the lower left corner. Here’s some perspective: the dust cloud you can see is about 200 m across. That’s nearly two football fields long. This led me to another image taken in 2008 showing FOUR avalanches, which readers are encouraged to peruse at their leisure.

Wednesday, August 2, 2017

Frozen Moons

This week, Keagan Lee, an Undergraduate Research Assistant working at PVL for the summer reports on some independent reading he has been doing on a fascinating solar system object: Europa. The image above is a well-known mosaic acquired by the Galileo Orbiter, which you can find on the Planetary Photojournal here.

By Keagan Lee

We like to think of Earth being in the “Goldilocks Zone” -- an area in a star system that is not too cold and not too hot so that liquid water can exist on its surface -- as if this is the ideal location in the solar system. We call Earth the “Blue Planet” because it has so much water. Ostensibly, yes. In our neighbourhood, we are the largest host of water; any water that made its way to Mercury (outside of the permanently shadowed polar traps) or Venus would be boiled off instantly, and it is too cold for water to exist in liquid form on Mars, at least currently. But water is much more likely to exist further out in the solar system where the effects of solar radiation are lessened because of the distance from the Sun and, as a consequence, is found in the form of ice. Europa, one of the moons of Jupiter, which is less than 1% the mass of Earth, is estimated to have more than twice the volume of water than Earth!