The image runs without trouble through astrometry.net; scale is 1.06 arc-seconds per pixel, it's in northern Sagittarius (18 18 49 -20 53 13)

http://nova.astrometry.net/user_images/1573114#annotated

The fuzzy blob in the top right corner is a reflection nebula, so an honest fuzzy blob on the sky; the optical portion doesn't seem to have a name, the nebula is much more obvious in infra-red (use sky.esa.int and the 2MASS sky)

I'm a little worried about planetary protection issues. Dragon is built in a clean-room, but it's not microbially cleaned, and I imagine 'also survives three days in 200C ethylene oxide' is quite a hard requirement to stick onto a vehicle which hasn't been designed with that in mind from the offset. It would seem a pity, after all the effort involved in cleaning Viking or Curiosity, to send that large an unclean vehicle.

I love the way that you can see which moons are nearer the planet from the different sharpness of the edges of the shadows

How hard is it (in delta-V terms) to launch a probe into orbit around Halley's Comet?

The orbit is obviously very eccentric; also inclined and retrograde. From the example of Ulysses, a suitable Jupiter flyby can put you into an orbit which is inclined, retrograde, and with aphelion at Jupiter, but I have no idea how hard it is then to raise aphelion and lower perihelion to match the comet.

It sounds the sort of thing that an orbit-designer would have done as an example at some stage, but I can't immediately find it on the Web.

http://hla.stsci.edu/cgi-bin/display?image...olor)%20NGC1818

is the equivalent image from Hubble; I'm guessing they're using NGC1818 as a calibration target because it has the very distinct red and blue star series that you can see in the Hubble shot

Fairing diameter is one of the more absolute restrictions that shows up in mission planning.

Obviously there's a drag impact at liftoff, but I'd be very interested to see a quantitative analysis as to why a ten-metre-diameter fairing is not a practical object. Has anyone got a pointer to one?

I am unconvinced by that paper, as indeed are the authors; I think the graph showing transverse velocities all much higher than radial velocities is damning.

Those transverse velocities come from proper motions on a survey not really optimised for astrometry, combined with photometric distances. I think it would be best to wait for Gaia confirmation.

The part is a clock generator for an X-band transponder; equivalent parts apparently went wrong in some O3b Networks communications satellites launched in June.

How interesting is it to go to this kind of conference if you're an enthusiast but not actively working in the field?

Toulouse isn't far away and I can take a week of holiday to visit, but if the conference consists mostly of budget-planning meetings and cross-products reports of how eleven groups have achieved against fifteen metrics (I have heard some truly dreadful tales from my boss about EU major-project progress meetings in the past) then it's not going to be the best way to spend 500 euros.

I suppose I gatecrashed the IAU meeting in Sydney a decade ago and found it absolutely fascinating.

The ESA has plans for a followup mission 'PLATO' which is roughly SuperWASP-in-space: twenty-eight 100mm rich-field telescopes, each with a (2x3854x18µm)^2 focal-plane array, mounted on a single very stable platform located at L2. It will cover a 550-square-degree field (a bit over 1% of the sky, five times Kepler); the idea is to look for planets around rather brighter stars than Kepler (because follow-up for Kepler apparently proved harder than anticipated), and with a bit more of a focus on asteroseismology (in particular, with the aim of characterising the planet-hosting stars by seismology rather than by ground-based observation).

http://www.lesia.obspm.fr/perso/claude-catala/plato_web.html

That's a nice paper, but I don't believe this is a W UMa, because they tend to have periods around ten hours and this one has a period of fourteen days. There are lots of W UMa stars in the gallery, visible by the thickness of the band at the small size of the thumbnails; http://www.chiark.greenend.org.uk/~twomack...C0102806220.png (period ~.349692 days, phased light curve http://www.chiark.greenend.org.uk/~twomack...-phased-.349692 ) looks a classic example.

I'm thinking it's a beta Lyrae with components of very different brightness, which I suppose is the same as an Algol with an elliptical primary; period looks about 13.58 days and when you phase on that the secondary eclipse becomes visible. Data (time/flux pairs) attached if anyone happens to have a binary-star-modelling program; when I think of modelling rotating ellipsoids from scratch, my head fills with ℘ symbols, and I hope somebody else has already written the software even before I think about limb-darkening.

I notice that the raw data is now available at http://idc-corotn2-public.ias.u-psud.fr/in...sva=browseGraph at least for the first two sessions of COROT observations.

I collected the monochromatic data for the initial session, which is 5600 data series each of about ten thousand points; easy to parse, and my initial analysis was to find ones where the standard deviation of the measurements divided by the average of the measurement standard deviations was large, and then to look at (99th percentile brightness - 1st percentile brightness) / (1st percentile brightness): that gives the gallery at http://fivemack.livejournal.com/182633.html#cutid1

The pretty curves are mostly eclipsing binaries; could someone give me an idea of what the geometry implied by a light curve like http://www.chiark.greenend.org.uk/~twomack...C0102791304.png is? I can get periods to four decimal places by trying to minimise the sum of the standard deviations of the amplitudes in 64 buckets collected under the purported period, but I don't see how to get to the six decimal places that astronomers often seem to mention for orbital periods.

I assume that cataclysmic variables are much less common than cosmic-ray hits on the CCD, but I don't have a very clear idea how to go about cleaning up the sudden jumps that you see in time series like http://www.chiark.greenend.org.uk/~twomack...C0102741414.png - I don't think that 30% jumps in flux in less than one 512-second sample period are likely to be of astronomical origin.

At least the Japanese Ibuki satellite seems to have launched successfully, and as far as I can tell it's doing much the same mission as OCO; I don't know what's lost by having only one set of CO2 measurements, but one is a lot better than zero.

http://celestrak.com/SOCRATES/top10maxprob.asp almost always shows at least one expected pass at 0.1km or less, with an estimated probability of collision more than one in a thousand; since we don't see a collision every few years, I suspect their model is not perfect.

From a 500km circular orbit, a change in velocity by 1 centimetre per second changes the radius of the orbit by 18 metres, so you have to know the velocity very accurately indeed.

I presume that it is completely infeasible without a very powerful nuclear reactor and many years' production of ion engines to do anything remotely like Dawn in the Kuiper belt - the distances are just too long.

Is it in fact feasible with current technology even to get a probe into orbit around Haumea or Makemake? I'd suspect not, that the speed you need to get it out to the Kuiper belt in a lifetime is much too great to cancel down to orbital velocity.

There's some reasonably interesting information to be gleaned from the presentations at the workshop on COROT a few weeks back at the Paris Observatory; start at http://ecole-doctorale.obspm.fr/rubrique200.html and get repeatedly annoyed by the interface they're using for storing presentations. Do so quite soon since they're taking the presentations down at the end of October.

It's mostly grad-student-level material on asteroseismology and spacecraft design, but there's more information about the data-processing issues with COROT than I've seen elsewhere, and a few more light curves.

I bought one in January 2005 and have been using it ever since; it's a beautiful, silent and reliable machine.

You probably want to get Apple to fit 2GB of memory; the one I have is the 512MB model and runs out of memory with 10,000 pictures in iPhoto. The internal disc is fairly small, but external Firewire or USB2 discs are fairly cheap; Lacie does one in a case to match the Mac Mini.

http://www.spaceref.com/news/viewnews.html?id=1237

reprints an interesting Aviation Week article suggesting a push for proposals for new Discovery-sized missions to use closed-loop Stirling cycle nuclear power systems, aiming for launch around 2013. It's unclear how the shortage of 238Pu is being resolved, though the Stirling-cycle devices use two 250W_thermal units of 238Pu for 143W output, whilst the Cassini/New Horizons RTG uses eighteen units for 285W electrical output.

http://nspires.nasaprs.com/external/viewre...ationDocument=1 is a summary of the specs of the Advanced Stirling Radioisotope Generator; http://esto.nasa.gov/conferences/nstc2007/...ations/D2P1.pdf is quite a nice presentation of the technology development.

The engineering history seems to be by way of Stirling-type cryocoolers, of which ten have been running for more than 10k hours each.

The Corot photometry is wonderfully stable, and looks as if it can pick up eclipses on a single occurrence rather than having to do a phased integral; Jupiter's diameter is 1/10 of the Sun, so a Jupiter transit would be a 1% drop in light, which Corot would pick up very happily, It would last (I think) jupiter_orbital_period * (sun_diameter / 2*pi*jupiter_orbit_diameter) = 4330 days * 1.4e6 km / (6.28 * 778e6km) = 1.25 days.

I don't think there's much that dims a star in a spectrally-uniform way with a flat bottom and that kind of ingress and egress period, so you would really see it in the data. I don't know how long Corot will last, it's working in the optical spectrum so doesn't have cryogens to exhaust, and it doesn't have to do very complicated station-keeping so the fuel should last reasonably, but two Jupiter-years is maybe a little long to expect, and the cadence where it looks at Monocerus for six months and Scutum for six months starts to be troublesome at the longer periods.

I'm looking forward to seeing the low-mass and long-period bits of phase space get populated, and to hearing complaints that there's not enough high-resolution-spectrograph time available to follow up all the transit detections!

http://news.bbc.co.uk/1/hi/sci/tech/6611557.stm

is reporting that Corot has found its first planet. I can't find an arxiv paper about this, or even a press release, but there are many here better at squirreling out data releases than me.

1.3Mj, 1.8Rj so it's a very inflated planet, 1.5-day orbit around a 'star quite similar to the Sun' might account for that. In the Monoceros field (Corot is now pointing at the Scutum/Aquila field).

I've been wondering how you'd design a Meteosat system for Jupiter.

There is of course the initial question of why you'd want to ... the images would be intrinsically beautiful, it's an interesting domain of turbulent fluids, forecasting the weather on a second planet might help with forecasting on ours, but really it just looks pretty.

Jupiter-synchronous orbit is stupidly low and very radiation-filled, so you'd probably want to observe from the distance of Callisto, and you'd need three satellites at 120-degree intervals around that orbit. A camera like the one on Deep Impact would give a resolution of four kilometres (2 microradians at two million kilometres) on Jupiter, which is I think rather better than anyone's achieved before even at fly-bys. It would let you get very good observation of Ionian activity, with about an 800-pixel disc, though I suspect it wouldn't tell you anything very exciting about the less active Jovian moons.

I suppose far-Jupiter-orbit insertion is intrinsically too expensive for this to be a remotely feasible mission; I've not found very good details of what the outer radiation belts of Jupiter look like, it may be that Callisto orbit is still absurdly unfriendly compared to LEO.

I think you could get full-globe images by combining pictures from multiple weather satellites, but obviously you get no more than a hemisphere from anything in GEO. Earth is (if I've done my sums right) 20 degrees across from GEO, so you need some sort of scanning platform to take your detector across Earth.

Ah, this is already done: http://www.ghcc.msfc.nasa.gov/GOES/globalwv.html has global images composed from GOES-EAST (over Peru), GOES-WEST (over the Pacific), and the two Meteosats over the Bight of Benin and Sri Lanka. I suspect there's a Japanese satellite filling the gap east of India.

These don't show the poles very well for geometric reasons, and are monochrome (OK, they're trichrome, but those are 10.8u infra-red, 2u infra-red and visible).

The polar Earth-observing satellites (say http://rapidfire.sci.gsfc.nasa.gov/) get any point on Earth every few days, but clouds move fast enough that the pictures will look pretty ugly and not line up.