The Solar System: a proving ground for interstellar spacecraft

The above picture illustrates a small spacecraft attached to a solar sail, as depicted by By Kevin Gill from Nashua, NH, United States ( Solar Sail, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=42599221 ). Such Solar/Laser sails are the only technology currently proposed for travel to other solar systems in a reasonable amount of time and, as of yet, not practicable except on paper.  Of course, such "starchips," as they are known, would have to be much smaller than the spacecraft pictured above and would travel in larger numbers ("think smaller, think way more legs"). Hugh Podmore and I wondered what the advent of such a technology might mean for planetary science within our own solar system.

Late last year I finally published a fun paper that myself and Hugh Podmore, one of Prof. Regina Lee's PhD students, wrote up in the summer of 2017. It was a pure flight of intellectual fancy for which we sought and received no funding. What was the subject, you may ask: what else could you do with the starchip spacecraft that the breakthrough star-shot initiative is working towards in order to advance our knowledge of our own solar system? While some of the possibilities had been detailed in the original paper by Prof. Lubin, his ideas for how the interstellar laser array could be used to explore the solar system go big whereas we wanted to know what could be bought in terms of time and cost for going small instead.

It seems that there is a quite a bit that one could do. But what surprised us most was how quickly such spacecraft could be of use to planetary science, perhaps as early as the mid 2020s, allowing early starchip prototypes to be tested out while doing valuable science.  They could also be a democratizing force by allowing smaller space actors (such as Canada) to participate in a way that hadn't been previously imagined, due to the  relatively low cost of laser propulsion once the pushing station is set up. Finally, if you stop to think about it, there really are a lot of great uses for small, fast spacecraft. In our solar system there are things that are fiendishly difficult to do with a discovery-class NASA mission or that simply don't justify that classification's $500 million price tag. I'll get into all these interesting possibilities just below the cut.

5 years, 7 months and 25 days (Tenure)

You may think it's a bit silly, but I do have a thing for a well-made watch. I have a tradition of picking up a new one for major milestones at work (if you can call something you've done twice a tradition!). At right is the Seiko Premier Moonphase from my hiring as an Assistant Prof in 2012, the 62MAS Prospex Diver at left is the latest addition, doubling the size of the "collection." There's something about the simplicity and clarity of the latter that I appreciate now, much as I did the clockwork complexity of the former six years ago.

On the 26th of July this year, I finally got the good news from my President - I have been granted tenure! For those fans of this classic post that makes it 5 years, 7 months and 25 days since I began work at York University as an Assistant Professor. It's significantly longer than I spent as a postdoc and just a shade over the time spent in graduate school (5 years, 4 months and 7 days). I would have posted earlier, but I've been processing this news. In fact, I'm still processing. But, as is typical for this space, I'm feeling the itch to write and so I'm sharing my half-formed thoughts with you now.

But first; not all of you might be familiar with the concept of tenure. Why does it exist? What does it mean? Why do I/we care? And, what is it for? Perhaps a little background is called for. At most Universities, (but notably not all) most starting appointments, what would be in Canada and the United States called an "Assistant Professorship," is in fact a limited-term contract. The deal is that you will teach, research, serve the community/university and mentor graduate students for a period of time (typically 5 years). At at the end of that time, your fellow professors (Associate and Full) will weigh in and determine whether or not you meet the standards of your profession and merit being awarded a continuing position. Deans and other Senior Administrators also get a vote on this, however, at least at York it tends to be the lower-level committees that present the largest hurdles.

A Half Century of Publishing? (or: fun with metrics)

Too much fun with metrics? This plot shows an h-value graph based on my google scholar citations (As of December, 2017). A researcher's h-value is the number of papers written by an author that have been cited at least that many times. For me, that number is 26 (if you trust google!), which is where the red and blue lines cross in the chart. In the article below, I discuss the sorts of fun an analytical person can have with metrics. But Science is about much more than just comparing these sorts of numbers. Ultimately if you enjoy what you research, and that work is useful to others, what more do you need?

(Editorial Note: I'll be lightly editing the various posts I had created over the last year and a half as I put them up, where I've made changes, these will be noted in italics in brackets).

It's taken almost as an article of faith that a successful scientific career consists of 100 peer-reviewed publications. If that's the case, then as of November (2017) I'm halfway there Breaking the 11-month logjam at 49 papers was my methane update and, as predicted in my summer post, there has been more to come with five acceptances having followed since that time, nudging my number up to 55. If everything currently in the submitted and just about to be submitted categories follow suit, it might be 60 before the end of 2018! (indeed, it's now 62)

It seems, therefore, that this is as good a time as any for some reflection. It doesn't hurt that it is currently December (2017), the official month of reflection, and that my first sabbatical was recently approved for January of 2019. First sabbaticals are a classic break in the academic race, a time after you've established yourself to take a step back and consider where (scientifically speaking) you'd like to go next. Perhaps, then, I'm just being a bit precocious here in getting started on that longer-term thinking. Though I shouldn't get too far ahead of myself since I won't hear back with finality on Tenure and Promotion for several months yet.

A Long Hiatus

It has been a year, 4 months and 10 days since I last posted, which I'm pretty sure is a record for this blog. Decidedly, it has been a very long hiatus. It's not so much that I stopped writing - very hard to do that - and indeed, I did write quite a few posts that are more or less ready to go. But in all that time, I just couldn't bring myself to hit the post button. So much second guessing about how others might read and interpret what I had to write*. Not to mention a great deal of wondering about why I should bother. Overall it just seemed to be an easier thing to simply put this conversation on hold.

While I was away, I've been busy. There's been a fair bit of stress, some unexpected challenges and a great deal of soul searching. I'd love to tell you that's all done now. But I don't think I'm quite there yet. Still, I've been feeling that it's time once again to put digital pen to digital paper, just in case this record is of any use to any of you. It's certainly been therapeutic for me, once or twice over the years! Besides, this has never been a sanitized "best life" record of my career. Frankly, I have a hard time understanding how such things are useful to anyone, including their authors.

So, in the interest of moving forward, allow me to sum up what has been going on in the last 16 months. 

There have been some definite highs in there: As of last August, I'm now a tenured professor at York and I was inducted into the Royal Society of Canada (!!!) last November - something I wouldn't have dreamed possible when last I posted (though I do know that even things we dare not dream can come true). I'm also now the director of a $7 million research network - which is thrilling and terrifying in equal measure; though I've found more confidence and encouragement than I expected when I took on the role.

However, on the other side, there have definitely been some lows. The tenure process is not an easy one and I must admit that I'm still working through some of what happened and what was said in the process. I'm told by colleagues at other Universities that this is not uncommon. I also served on a jury in a major criminal trial, something which permanently changes you in ways you don't expect. Last but far from least, my ophthalmologist likes to say that the warranty on a human being expires around the age of 40. For me, that seems to have been more like 37. I've spent 8 of the last 16 months on medication and my doctors cannot seem to figure out the problem. I suppose it shouldn't be a surprise to someone who works on the edge of a physical science that there is a huge gulf of the unexplained in medical science. Only TV medical dramas seem to tie up all the ends neatly with a diagnosis and cure within the hour; for the rest of us reality intervenes.

So there you have it. Look to this space over the coming weeks for a number of long-delayed posts. I might even have something to say about my Sabbatical which I'm currently enjoying down in Canberra, Australia with my unbelievably gracious hosts here at the Australian National University. Not to mention some of the exciting ideas for upcoming work that have been brewing.

___

*Ahh the tenure process, is there a better crucible in which to forge self-doubt?

A small step towards solving the mystery of martian methane

What does the seasonal cycle detected in Curiosity's record of methane concentration mean? Last week, I published a paper in Nature Geoscience with eight of my colleagues that attempts to answer that question. In the spirit of what I put together for my Nature penitentes paper back in January of 2017, I've decided to summarize the work here. This work was three years in the making, but the story of how it came to pass is much less exciting than with the penitentes - simply a combination of hard work and tenacity by my colleagues and I, like all good science. You can't tell the story of my paper without knowing the story of Martian Methane. So I've put together a primer. For those of you who have been following this closely, skip down to Chapter 2.

Chapter 1: The methane story so far

Whither methane, Mars' most mysterious gas? Since it was first discovered telescopically by Michael Mumma's group in 2003, methane has captivated our interest in the red planet. And with good reason: on the Earth, most methane is produced by biology.

Could the same be true on Mars? That's a complicated question to answer. For starters, there's very little of the stuff to go around. On Earth, methane makes up just under 2 parts per million (ppmv*) of the atmosphere, whereas on Mars the values recorded by different groups place the value at between 0.5 and 50 parts per billion (ppbv*) of the much thinner atmosphere. That allows other processes to have a significant effect. For instance, serpentinization of rocks at depth can also produce enough methane to explain these values, as can seeps of methane stored during Mars' early history either as organic carbon compounds or in methane clathrates. Heck, there's even enough accretion of organic matter via Interplanetary Dust Particles each year to produce 11 ppbv if it all gets converted into methane! None of this even considers processes that remove methane from the atmosphere.