Oh frosty, frosty Pluto, how you tantalise us. So small that even the most powerful telescopes can only discern you as a handful of pixels, yet immutably fascinating every time we learn something new about you!

I've written before about the insane seasonal variations experienced by the little world, and the Bad Astronomer wrote a good summary of why Pluto's atmosphere is actually upside down. Most recently though, last week NASA released the most detailed images of Pluto ever recorded. And very pretty they are too! Granted, they still don't have enough detail to pick out individual surface features like craters or mountains, but they're pretty impressive all the same. Incidentally, these images were taken quite some time ago. It's taken 4 years of computer processing to boost the image quality even this high!

Even with all of that image processing, we can get can still only resolve features a few hundred miles across, but this is still enough to see that this tiny little planet is full of fascinating variations. A molasses coloured world mottled with dark splotches and occasional light patches. From the picture, it's certainly easy to imagine you're looking at northern highlands and tarry southern seas of nitrogen and tholin. Alas, it's still speculation for now. Just a few more years for New Horizons to arrive and we'll suddenly get a much better view of the place!

One thing is for certain though. Pluto is an incredibly dynamic place. Some used to believe that being so far away, Pluto would be frozen solid. Unchanging and alone in the darkness. Evidently, this couldn't be further from the truth. These two black and white images show maps of Pluto's surface recorded in 1994 and 2002/03 respectively. The changes are actually quite astonishing. In fact, without knowing better, it would be easy to believe that these are maps of two different planets. Just imagine any part of Earth transforming that much in just a decade.

The reason is almost certainly the huge variations in temperature caused by Pluto's eccentric orbit. Between 1988 and 2002, Pluto's atmosphere nearly doubled in mass as it drew closer to the Sun and ices sublimed into gas. Now it's starting to retreat further out again, and obviously those gasses are starting to freeze out again.

One thing which has everyone puzzled is that brigh spot towards the right of these maps. It's an area rich in carbon monoxide ice, and no one knows quite why it's there or what's caused it. Personally, I think it would be fascinating if it's some kind of cryogenic geological (cryological?) feature. Perhaps a cryovolcano which somehow erupted due to the additional recent insolation. On Earth, carbon monoxide has a melting point of 68K, some 25 degrees higher than the average surface temperature on Pluto. But then, Pluto has a much lower pressure, and it varies greatly. Maybe such volcanoes could erupt seasonally. Or alternatively, perhaps the cause is more likely to be a geyser, similar to those seen on Triton and Enceladus. Whatever the cause, it certainly makes this a dramatic feature next to that patch of black material. The nature of that black material is also, incidentally, still a mystery.

I have a feeling that Pluto's going to continue to tantalise us all for many years to come, even long after New Horizons has been and gone...

Source (images and information): NASA press release

One of the things I really love about astronomy is the fact that there's so much in the Universe which nobody understands. I love a good mystery, and Epsilon Aurigae is a very good mystery!

In the constellation of Auriga, it's a bright white A-type supergiant star. With a magnitude of around +3, it's easily visible in the night sky if you know where to look for it. But all isn't quite as it seems with Epsilon Aurigae. Roughly every 27 years, it suddenly drops in brightness by one magnitude. It then stays dim for about 2 years (around 640-720 days) before rapidly returning to brightness. The reason why is still an open question.

The curious variable nature of Epsilon Aur was first noted in 1821 by Johann Fritsch, but wasn't studied properly till around 20 years later, by Eduard Heis and Friedrich Wilhelm Argelander. They were fascinated, not only by the dramatic dimming of the star, but also by its short term variability. Since then, a number of possible explanations for the 27 year fadings have been put forward. The currently favoured explanation is that Epsilon Aur has an unseen orbiting companion. A companion surrounded by a big dusty disk 4AU in diameter and 0.5 AU thick. If this companion was to pass between us and Epsilon Aur in its orbit, it would eclipse the central star, causing the dimming. It's believed, in fact, to be a big B5 star enveloped in dust.

While the details are still under debate, Epsilon Aurigae has been under a lot of scrutiny lately, after it was publicised during the end of IYA2009. Being observed under the collaborative Citizen Sky project, it's going to be dim for the rest of 2010. I wonder what might be waiting in this star system, to be discovered...

Image Credit: Alson Wong and Citizen Sky.

What do you do if you happen to be piloting an alien spaceship near to an average looking G5V class star somewhere near the Orion Arm of the Milky Way galaxy? Try not to be spotted by any local space telescopes, that's what!



Well, ok, it isn't an alien spaceship. Though you must admit, it does a very good impression of this Centauri Vorchan Cruiser from Babylon 5. Hubble recently imaged this curious looking object. Travelling at around eleven thousand miles per hour, it currently goes by the catalog number of P/2010-A2. But what exactly is it? In all seriousness, nothing quite like this has been spotted before, which implies it's either something new, or some rare event. Either way, it's cause for scientists to be excited.

It isn't a comet. It's a bit like one because of that tail, caused by tiny dust particles being blown away by radiation pressure.* But beyond that, it doesn't look like a comet. The dusty gas clouds around comets are a lot smoother-looking, without any of those apparent filaments, which seem to have been thrown out from the nucleus of this object. Perhaps stranger still, is the fact that its apparent nucleus is actually not in the centre of that cloud of dust where you'd expect it to be, but sitting just outside it (the white spot towards the left of the image above).

When all's considered, the most likely explanation is that Hubble managed to spot an asteroid collision. Two previously unknown small asteroids smashing into each other and creating a huge cloud of dusty debris which is now streaming out behind them. Interestingly, though you can't be certain by looking at the image, only one large object seems to be there. Maybe the less resilient of these two space rocks disintegrated completely in the collision. Or maybe it's just lost in the middle of that dust cloud somewhere...

Statistically, it's to be expected that asteroids must collide from time to time. After all, the Solar System's full of them.** But to catch them in the process of actually colliding? That's just cool.



*Radiation pressure is the pressure caused by light. Photons of sunlight hit molecules and tiny dust grains and transfer their momentum, causing force. The effect causes the spectacular tails seen streaming from regular comets, as well as oddballs like this.
**In fact, asteroids too small to be anything more dangerous than a pretty shooting star pass closer to us than the Moon roughly once a week on average.

Now, I've heard all manner of stories about mysogynies in the academic world, from school level right the way up to senior academics. Frankly, I fail to understand how, in a supposedly enlightened age, such things can endure. Some of the stories I've read on blogs like Female Science Professor make me want to apologise on behalf of my entire gender sometimes. And then I see things like this news article, posted on a friend's Facebook page...

The title alone, "Self-doubt plagues female astronomers" leaves little uncertainty as to what the rest of the article is about. Essentially, a study was done to investigate how many astronomers are fearful that they might be exposed as having a lack of knowledge. At least in the groups surveyed (in US institutions), women are more fearful than men in regards to being "exposed".

I have to say, I'm not entirely sure what to make of this. As with a lot of sociological studies, the sample size is fairly small. Scientifically, I'd have to say that further study is warranted. It would be interesting to see if this graph changes geographically. Are people less concerned in Europe than in America? What about China, India or South America? It's also noteworthy that in both genders, the majority vote was for "agree". Feelings of inadequacy are a fear for both men and women. On the other hand, more women "strongly agree", which does hint at a greater lack of confidence. Could it be that women are more fearful than men? Alternatively, could it be that men are simply less likely to consider a lack of knowledge in some areas to be a problem? These are open questions which it's difficult to speculate on. It's also notable that female professors are quite rare in physical sciences. Lecturers less so, but professors certainly. One has to wonder if it would be helpful to have more female role models like good old Jocelyn Bell Burnell.

If I'm perfectly honest, my gender notwithstanding, showing a lack of knowledge is always a concern of mine. I'll admit that it's probably irrational. No one can be expected to know everything about everything, and in research it seems remarkably common for people to become so engrossed in their own specialty that they start to lose track of other fields. That's a big part of why I keep this blog. To write about things, I need to read about them. If I read it helps me understand. Maybe it's true what they say, that knowledge is power. Or mayhap it's just academic currency. All the same, from an inside perspective it's easy to see how a lack of knowledge can feel like weakness. It feels almost darwinian at times. Survival of the smartest, perhaps. Rational or otherwise, thoughts like these running through my mind are usually enough to make me think twice about raising my hand to ask a question at the end of a seminar.

The so-called "impostor syndrome" has apparently been documented in all parts of the academic world (and indeed, elsewhere too). It's characterised by paranoia and unfounded feelings of inadequacy. The impression that one doesn't belong where they are and is at constant risk of being discovered and cast out -- even inspite of overwhelming evidence to the contrary. Feelings like this can really add to stress levels, as well as sapping motivation. In the most extreme cases, it's easy to see how impostor syndrome could cause someone to actually change professions. In fact, it's lamentable how many brilliant minds may already have been lost in this way.

So what can be done? Well, irrespective of gender, not chastising others for a lack of knowledge would certainly be beneficial. Likewise, teaching people to realise that sometimes you need to feel a little bit ignorant. Sometmes, that's precisely what should give you the motivation to improve yourself. It isn't always immediately apparent that, if ever you're worried that you don't know enough -- everyone, from undergrads to vice chancellors have felt the same way in the past. And probably still do. The bottom line here is: several of my most respected colleagues (and very good friends) are women. Should any of them ever consider leaving astronomy due to the feeling that they aren't good enough, I'd be dismayed.

Image credit: AIP/AAS
Source article: NatureJobs.com

So I've had a rather frenetic few weeks. Seriously, I've been busy with all sorts (and I really do mean all sorts). As a result, I guess I've been a little poor as bloggers go. But such is the life one lives when pursuing a PhD.

What is cool though is that coming up, I have two whole weeks of observing time in South Africa! Yeah! Those lovely people at the SAAO decided to approve our application. Stars shall be looked at. And spectra shall be taken. Oh yes. I'm really rather excited about the whole thing!

Anyway, no time to write much now. After working all week only to find out that my deadline got extended quite generously*, it is now my intention to go and drink beer.



*By which I mean so generously that it's less of an extended deadline and more of a distended deadline.

The UK is currently in the midst of a grit crisis. Amusing, but true. Snow keeps falling and ice keeps freezing (coldest winter since 1963, apparently), but that lovely mixture of sand and salt the city and county councils throw on the roads to keep them useable is starting to run low. What an odd situation. Mind you, feel free to call me a geek, but the physics of the whole ice/salt combination is quite interesting...

So the basic idea is simple. Pure water freezes at 0°C. Adding salt to the water increases the entropy (disorder) of the system. In simple terms, that added disorder makes it more difficult for water to form into crystals, causing the water to freeze at a lower temperature. Antifreeze works in a similar way, with an ethanol/water mix -- having the added benefit that ethanol has a lower freezing point than water, on top of the entropy effect. But there's another side to this entropic chicanery.

When salt dissolves, it's actually an endothermic process. In other words, dissolving salt in water requires heat, and it will actually suck heat out of its surroundings in order to dissolve. The reason being that the entire thing is driven by entropy. The Universe apparently likes things to be disordered. Any system will try its utmost to be as disordered as possible, even if it needs to steal heat from elsewhere in order to do so. The effect of this is that the overall temperature drops. Quite a lot. Lab chemists sometimes use this effect to make an ice-salt bath. Crush some ice, add some salt, watch the temperature plummet. I've had these things so cold before that they could freeze moisture out of the air. So the question is: if your front doorstep is already covered in snow, is throwing salt all over it a good idea?

Well, yes, in the long run it is. Thankfully your doorstep isn't a closed thermodynamic system, so while the salt will temporarily cause the ice to get a lot colder, eventually the temperature will equalise with its surroundings. The salt-ice will melt into salt-water and will tend to stay that way. Unless you live in Antarctica. But thankfully it isn't quite that cold here!

Thursday and Friday of this week were spent at the Astrophysical Chemistry Group's meeting, Astrochemistry at High Resolution, which proved to be quite a treat! Hosted by the Jodrell Bank Centre for Astrophysics, in Manchester, the meeting turned out to be a veritable smörgåsbord of interesting science. Actually, I mean that quite literally, given two days of short talks, discussions and research posters, a smörgåsbord would be a very good description. Participants and fellow attendees ranged from plasma chemists to lab spectroscopists, to radio astronomers.

Actually, perhaps the most interesting thing was being able to glimpse the other parts of my field. Myself, I'm a sort of weird scientific hybrid between an optical stellar astronomer and a theoretical organic chemist. Not only seeing the work others are doing, but seeing where my own fits is very interesting indeed.

Plus, events like this give me a few interesting ideas of things to do in the future, both theoretically and observationally. Interesting stellar sightlines and correlations between astrochemical species.

I'm still going over the notes I took, but I suspect I might muse upon this further in the near future. A good conference is always enjoyable. I see it as a pleasant end to the mountain of work I'm in the process of wrapping up.

(Until the next mountain, at any rate).

I always like going to the sea. I find it humbling. Nothing but water for as far as the eye can see, yet only a small fraction of this planet which bears us all in our voyage through the cosmos. The horizon seems so much closer to me now, than it ever did before. Practically within reach. A reminder of just how small planet Earth really is. Small and isolated. Compared with the immense distances to the stars, a mere horizon seems just a stone's throw away. I like to look to it sometimes and contemplate the size of our little world. Take a deep breath and feel the planet turning beneath my feet.

I may have said this before, but the interesting thing about studying astronomy is that you end up holding stars inside your mind. The stars ceased to be mere points of light to me a long time ago. When I look at a night sky now, I see places. Some so close I'm seeing their light from just a few years ago. Some almost unimaginably distant. I'm also aware of the places which I don't see. The ones so far away that their light is far too dim for my feeble human retinas to detect.



The sea itself is a constant reminder of how the Earth moves, playing its role in the vast machinery of the cosmos. Pulled at by the gravity of the Moon, the sea is in constant motion. Buffetted by kinetic friction from the wind. Roiling in turbulent waves, breaking into a billion fractal droplets of water as they crash to the shore, finishing as little but a fine mist of spray to moisten my skin and leave the faint taste of salt on my lips. Countless trillions of water molecules, all in constant motion, spinning and resonating in harmony. Tiny fleeting hexagonal shapes and forms gather within the water, too small to ever be seen, held together by tenuous intermolecular forces, before almost instantly they dissipate and return to the morass of water molecules from whence they came. Nature is a beautiful thing.

So it's now the last day of 2009. It's sometimes nice to take some time out at the end of the year to reflect on things. Gazing to the horizon sometimes has that effect on me. This year has been somewhat tumultuous, but the high points have been the highest of my life. All in all, on reflection, I think 2009 was a fine year. Here's hoping 2010 will be even better!

I'm gearing up for the final push with this report now. It's about half an hour away from New Year's Eve and I'm sorting through references. Most people would consider this some breed of madness, but I live in the world of academia and this is the life I have chosen. I stand resolute. Anyone familiar with the ebb and flow of university life can, I'm sure, sympathise.

Right now, I'm just picking up the pieces. Filling in all the references I need to fill in (63 and counting), making and finishing figures (6 diagrams and 37 electronic excitation spectra in total) and adding pertinent arguments to my discussion section. I intend to do what I can for now. The true final push happens when I get home. This will probably involve being conscious for over 24 hours, and if it goes according to plan, I should be finished by the evening before I need to submit it.

To be honest, sometimes you need to work hard to do these things. But they're so worth it. I really do love writing, and it's inherently gratifying to formlise your own work in written form. I suspect I'll be spending a large proportion of this year writing one thing or another. In a year's time, I'll probably be starting to plan out my thesis. There's a scary thought if ever there was one...

EDIT-- You know you've been spending a ot of time writing when you have a nervous tick of periodically hitting command-S. Thanks Firefox, but I don't really want to save update.bml. Don't mind me...

Incidentally, I would write more, but sadly I don't have much time for blogging at the moment. I'm still in the midst of writing this report. 5000-10000. Everything I've done over the past year. Well, the good news is that it turns out I've actually done rather a lot this year. The bad news...? I'm sure that should be self evident.

Normal service will be resumed shortly.

(Actually, it's looking pretty good at the moment, if I do say so myself...)