Rosetta space probe, Philae lander, comet 67P/Churyumov-Gerasimenko

[TTG4]

it turns out to look just like it did in the previous monochrome pictures - i.e. it's a very uniform grey.

I feel for the people who'd been working on that. Yeah it's a result and gives interesting data, but when you get a negative result like that there's always a feeling of 'ah nuts'

[Glaurung]

There's some more news and good-quality pictures from Rosetta, as reported by the BBC. About 70% of the surface has now been imaged to a resolution of about a metre, revealing features that include "goosebumps" and dunes or ripples. The comet also seems to be be very low density for its size, but there's no information yet on whether it's just fluffy, or has big holes inside.

[Glaurung]

More news from comet 67P. It's warming up - daytime temperatures are currently getting up to a balmy -43C. Consequently it's now emitting jets of gas, at speeds up to 800 m/s, and extending several km from the surface.

This has two effects:
- First, it's slowing the comet's rotation by about a second a day. This was detected when Rosetta's "navigators" at ESA found they were not seeing expected landmarks at quite the time they expected.
- Second, there's now enough gas in the space around the comet that Rosetta (with 64 sq m) of solar panels) gets blown around if it comes too close. It has had to retreat from a gravitationally-bound orbit within 30 km to a powered orbit no closer than 70 km.

All this from (as usual) a BBC New article.

[Glaurung]

And another dollop of cometary news, as usual via the BBC.

Data from Rosetta and Philae shows that the comet has no magnetic field. This is interesting because it implies that magnetic fields did not play a part in the formation of comets in the early solar system.

There's more information in a Science paper (subscription needed).

[Glaurung]

It's been quite a while since I posted on this thread. Data and pictures keep coming back, and news stories pop up now and then. This one (BBC again) is about some data from the lander, Philae. It was programmed to have a "sniff" of the gases around it ten minutes after landing, and it duly did so, even though it was bouncing well above the surface at the time. The results were sent back before Philae shut down, and have now been analysed and published. There's an interesting range of small organic molecules, including ones containing oxygen or nitrogen; some have never been detected on comets before. One of the researchers used the phrase "a frozen primordial soup".

For those less interested in the chemistry, the article also has some nice pictures, one of which looks to have been taken at or very near the surface.

[Glaurung]

Time flies: I hadn't thought it was over a year since I last posted in this thread. Anyway, Rosetta is still going around the comet - it's now in a very close orbit as the comet is no longer spewing out gas and dust. It can therefore get much higher resolution images of the surface, and so it's managed to find the Philae lander. As expected, it's in a dark hole, on its side.

Rosetta itself will end up on the comet too, quite soon - it's due to impact on 30 September, returning data as it closes in.

All this and some pictures in the inevitable BBC News article.

[Glaurung]

Today is impact day - in fact in about 10 minutes, as I write. The comet is over 700 million km away, so we don't get confirmation for another 40 minutes after that.