Monday, 27 February 2012

Long Distance Storm Chasing - A Plea for Help!

Last spring, Saturn’s gigantic springtime disturbance was characterised for the first time in the infrared, allowing us to measure the vertical temperature structure of a Saturnian storm system.  Our paper (Fletcher et al., 2011, Thermal Structure and Dynamics of Saturn’s Northern Springtime Disturbance, Science, 332, 1413--1417,, showed that the thermal infrared imaging yielded some surprises - not least was the dramatic effect that this churning, tropospheric storm system had on the usually calm and quiescent stratosphere (see Saturn image on the far right).  It spawned two warm airmasses, which we termed ‘beacons’ because of their impressive emission at infrared wavelengths.  These heated airmasses were tracked throughout 2011 by Cassini, the Very Large Telescope in Chile, and the Infrared Telescope Facility in Hawai’i.

Today (February 2012), a single large hot airmass remains in Saturn’s stratosphere, but there’s a big question remaining - does this have any impact on the visible cloud tops?  Indeed, one of the big challenges for giant planet science is relating visible changes in albedo and cloud colouration to environmental changes (e.g., changes in temperature, cloud formation or chemistry).  So far, our comparisons with visible light observations have suggested that the effects of the hot stratospheric beacon are completely invisible.  The chart above shows the expected longitude (System III West) of the beacon, and an Excel spreadsheet listing the longitude on each date through the rest of 2012 can be found here:  

As Saturn reaches opposition on April 16th 2012, the next few months provides an excellent opportunity to search for any unusual goings-on beneath the hot beacon.  To find the System III Longitude visible from Earth at any time, use the JPL Horizons Ephemeris Generator (with option 14 for the table settings).

Wishing you clear skies and happy storm chasing!


Tuesday, 21 February 2012

Becoming a Planetary Scientist

In 2012, I was asked a series of questions about how I became a planetary scientist, and what advice I’d give to school students wanting to get involved in this exciting field.  I’ve reproduced my answers here, just in case it serves to help any visitors to this site!

Job Title: Planetary Scientist

What do you actually do? 
I’m a planetary weather man, studying the physics and chemistry of all the atmospheres in our solar system to better understand the worlds around us.

What did you choose to do once you could leave school, ie at age 16?
Stay on at sixth form college to study A Levels – Maths, Further Maths, Physics, Chemistry, Biology and General Studies

What did you choose to do next?
Went to University:  Emmanuel College Cambridge to study for a BA and MSci in Natural Science, specialising in Physics.

How did you get to where you are now?  
When I left University, I really wanted to study a topic that I felt was close to home, that some day we could reach out and touch with our own hands, see with our own eyes.   Despite an interest in astronomy, I decided against studying the far reaches of our universe and chose instead to explore the planets of our own solar system.  In 2004, the Cassini-Huygens spacecraft was about to arrive at Saturn, and Oxford were looking for research students to help analyse the first data from the ringed world.  I spent my PhD characterising Saturn’s dynamic atmosphere, which then set me on a course to study all of the giant planets in our solar system in a series of short fellowships at NASA’s Jet Propulsion Laboratory and Oxford’s Planetary Physics department.  Today I use a variety of interplanetary spacecraft, orbital telescopes and giant ground-based observatories to learn more about the planets.

Were there other routes you could have taken to get this job?
Planetary science requires you to be a jack of all trades:  being a planetary scientist requires an excellent knowledge of physics, computing, maths and chemistry, so each of these topics would have allowed me to work in this exciting field, provided they’d been studied to degree level.

What do you like best about your job?  
Things can change quickly, and we have to be responsive to that.  If an asteroid strikes Jupiter, or a storm explodes in the atmosphere of Saturn, we have to bring all our experience to try to understand what’s happening.   So the days are never dull, and you rarely do the same thing from one day to the next!  I get to work as part of an international team of scientists, which means I get to travel far and wide to communicate my research and forge new collaborations.  Finally, we find ourselves in a revolution in this subject, with more missions and telescopes in flight than at any point in humankinds history – that means that the potential for new discoveries is enormous, and you never know when you might be the first human to observe a new phenomenon in our solar system.  The old adage is true – when you love what you do, you never work a day in your life!

What would your top tips be to a 16-year old considering working in this field?  
For any scientific subject, it’s essential to get a good grounding in maths and computing, as these topics go hand in hand.  So much of what we do requires the ability to write computer code and solve mathematical problems, that you really can’t escape it!  Without a doubt, you should forge ahead with A-levels, but never forget the bigger picture – there’s so much exciting science happening out there; if you read widely you might just stumble across a topic that really excites you.  That’s what happened to me with planetary exploration.

What would your top tips be to an 18 year old considering working in this field?
Think carefully about where you’d like to go for your degree, and make sure that the institution provides a good balance between science, maths and computing.  All three are needed to be a successful atmospheric scientist or meteorologist.  It’s all about building up a toolkit of experience, which you can then apply to new problems as they’re presented to you.  So be curious, don’t be satisfied with explanations that are unclear, and experiment for yourself.  Curiosity and the ability to solve problems are the traits that are essential in any independent research scientist, and will be vital as you head to university.

Tell us something about yourself.  
In the summer of 2009, I was having a barbeque on a sunny California day with my wife.  My boss called to say that an Australian amateur astronomer had spotted something rather odd near Jupiter’s south pole.  I raced to the office, where we could remotely use the telescopes in Hawaii to figure out what was going on, and we were in for a massive surprise.  A huge, super-heated plume of aerosols and debris had been lofted into Jupiter’s atmosphere by an asteroidal collision.  Without the data we took that Californian evening, we might never have been able to unravel the mystery of what had happened up there on Jupiter.  It was the chance of a lifetime, a stroke of luck, and provided us with fascinating scientific results for years to come.  It shows just how exciting this field is, and that there are so many surprises and marvels out there for us to explore.