Sticky Moments

April 3, 2008

I am back in Edinburgh after two days at the National Astronomy Meeting in Belfast, and then a day in St Andrews for the SUPA Advisory Committee. So today I will miss the session where STFC meet the community … I hope it will be positive, but it may well be a rather sticky moment. I had the feeling in Belfast that people were talking more about politics than science, but maybe that was just all the senior old farts like me. The grad students won’t have been wasting their time on politics. They will have been drinking beer.

I went to a talk by Don Pollacco summarising progress on discovering exoplanets, including an announcement that SuperWASP has found ten new transiting planets, a third of all those known. The exoplanet business is very exciting but puzzling as there are several odd and worrying things. there are too many elliptical orbits; planets only like high metallicity stars; and at a given mass they are nearly all larger than they should be. All these things are explained by theorists of course, but it feels uncomfortable.

Here is another piece of sticky discomfort. For years the standard picture of planet formation has this crucial period of time where grains start sticking together. Once they are big enough gravity starts to do its clumping thing, but first they have to collide, stick, and grow. So nobody ever tested this until recently, but now its been done by my SUPA chum Helen Fraser who runs an Astrochemistry lab at Strathclyde. She has a machine that she takes up on a zero-g parabolic flight ESA aircraft. She fires the grains at each other and makes a movie. They don’t stick. They bounce off each other and spin. She tried ice. It doesn’t stick either. Her last hope is spongy ice – fractal grains like those we do actually find in the interplanetary medium. (But how do they get made ?) She is in Bordeaux now about to fly with her toy. Sounds more fun than STFC bashing ..

Anyway, you won’t get a debrief on the STFC session from me .. hopefully it will be covered by Stu and Chris or the orbiting frog

Last but not least, we released the AstroGrid software on Tuesday. You can get it from