Emily has some new info in her blog installment:



I suggested a while earlier that maybe the crescent images weren't spectacular for them to merit public release. Seems this might be the case after all.

MOST.

Not all.

Doug

weren't spectacular for them to merit public release

You see, I don't get that at all... what, we're only allowed to see "spectacular" images now? I've sat through three mouse-clicking, RSI-inducing years of countless (clink) black and white pictures of MER sundials for pity's sake, so I don't care if they're "spectacular" or not, I'm ***interested***!! I want to see them, and share them with all the people I give my talks to, not just because, in a very small way, we all helped pay for them, but because it's what's supposed to happen. Isn't it? They design, build and launch the probes, they take pictures and measurements, send the data back, and we are told what they learned - or did I miss something? Did I miss a Part B of the Plan that states that the only people allowed to see the results are the people in the offices and labs, because the "Little People" couldn't possibly understand what the missions learned..?

Sorry, but I feel quite strongly about this. I'm busting my guts Out There giving talks at every opportunity, being an advocate for the world's space programs, trying to convince people that the money spent on space probes is well spent and wouldn't be better spent on other things, and when I come up against something like this it just makes my job so much harder.

I received word that VEx will be having, as mentioned before, a major release within a month, and that further releases should be monthly. I look forward to this, but I'll believe it when I see it.

OSIRIS camera on Rosetta obtains ‘light curve’ of asteroid Steins

http://www.esa.int/SPECIALS/Rosetta/SEMCC2R08ZE_0.html

I love the "relatively slow speed of about 9kilometres per second" note for editors. You know you're spending too much time in space when 40,000 kph is relatively slow.

Here's a Steins animation.

Information on Rosetta's Earth Fly-By 2

Someone was asking for information on the Rosetta fly-by of Earth in November 2007. I asked the Rosetta science ops people for some info.

The closest approach (CA) will take place on November 13 (DOY317). At the moment of closest approach, the altitude of Rosetta will be 5330 km above the Earth surface, at sub-surface position: 63°46' S, 74°35' W (local time 16:17). A glance at Google Earth shows the closest approach is above the Magellen Strait, between South America and Antarctica. Not the spot I would have picked, but that's why I don't work in Flight Dynamics.

The Earth solar elongation around closest approach shows a very unfavorable configuration for observing the Earth during the ESB2 event. The solar angle from +Z, towards +X, must not exceed 140 degrees for thermal reasons. We assume a minimum observing angle of 10° and a maximum angle of 140°. For solar elongation angles between 20 and 95 degrees, the duration of the attitude is not constrained; for larger angles (but smaller than the hard upper limit 140 degrees at 1 AU) the maximum attitude period is 4 hours. Attitudes with SEA smaller than 20 degrees would violate several instrument constraints.

Power and data rate are not expected to present any constraints, since we are at 1 AU.

Some of the ideas being explored for instrument operations are shown below.

ALICE (AL): UV spectrometer observations:
• decontamination) and dark exposures)
• 1 Earth pointing spectral calibration and flatfield using Earth Airglow)
• 3 Moon pointing observatoins with absolute flux calibration and flatfield using Moon’s limb, slit in N-S direction)
• 1 stellar pointing for calibrations with preferentially Vega

MIRO (MR): Microwave Instrument for the Rosetta Orbiter Observations:
• 2 Earth pointings to stare at Earth during approach and recession for detector linearity calibrations.
• 2 Moon pointings to stare at Moon during approach and recession for detector linearity calibrations.
• 1 Asteroid Mode sequence test run at closest approach

OSIRIS (SR): Science camera SR Observations:
• 3 Moon pointings for science – spectrophotometry of lunar disk), Moon Na/OH tail, also straylight calibration)
• 2 Stellar pointings for calibrations on Vega and 16 Cyg
• 1 Earth pointing for calibration and imaging, Spectroscopy and straylight
• 3 imaging observations

VIRTIS (VR): Visible and Infrared Mapping Spectrometer Observations:
• 1 stare to Earth terminator, repeated several times before CA
• 2 scans from Earth limb to terminator, repeated several times before CA
• 1 raster mosaic

PHILAE (LZ): Rosetta Lander Observations:
• continuous RoLand Magnetometer and Plasma Monitor (ROMAP) measurements 6 days before and 1 day after CA
• 1 imaging of different CIVA images during CA

Magnetometer (RP) Observation: continuous magnetometer science observation 7 days around the CA

Radio Science (RS) Observation: one ground station configuration for radio science anomalous acceleration measurement

SREM (SE): Radiation Monitor Observations: continuous science observation with increased sampling of 24 hours around CA

So to summarize what I take away from this, the trajectory is not great for observations due to observation constraints. We come in on the dark side, close to the terminator, which means we have the highest relative speeds with the worst observing conditions when we are closest. Still, the early planning has a lot going on. They'll try to catch more images with the Lander camera, like they did at Mars, but they are not certain what the orientation will be so it isn't at all certain yet. During the long cruise phase, the teams are not in place to do experiments. So the fly-by and the time around it will be used for a number of calibrations, which are important if not overlly exciting. Should be able to get some decent images as we sail away on the light side.

The ESA page on the Rosetta mission is at: http://www.esa.int/SPECIALS/Rosetta/index.html.
Rosetta Science page: http://www.esa.int/esaSC/120389_index_0_m.html

Hope that helps.

-Don

Any idea how close the lunar approach will be? I remember it being quite distant last time.


Ted

Rosetta and New Horizons watch Jupiter in joint campaign

http://www.esa.int/esaCP/SEMHFHT4LZE_index_0.html

More like "Rosetta and New Horizons watched Jupiter in joint campaign".

From the article:

"Rosetta’s observations are set to continue until 8 May, and when complete,
will include some 400 hours worth of observations."

Yeah, but I was adressing the fact the joint part of the observations is over. Probably has been for quite a while now.

The flyby portion of the joint study is over, but joint observations do continue.

From: http://www.planetary.org/blog/article/00000875/

"Feb 28
03:00 Turn to Jupiter for New Horizons flyby support
[activity descriptions removed -- CW_II]
08:00 End New Horizons Jupiter flyby support

Mar 1
19:30 ALICE observations of Jupiter begin
Following its flyby, New Horizons will exit the Jupiter system by flying down Jupiter's magnetotail.
Rosetta will be able to study the Jupiter system using its ALICE instrument from outside the magnetic
field at the same time that New Horizons studies it with its own ALICE instrument form inside the
magnetic field. The observations will take place in a total of 22 blocks over the next two months,
each block lasting anywhere from an hour to nearly four days.

May 9
17:30 ALICE observations of Jupiter end"

Hm... didn't the article mention NH's ALICE can't turn back to Jupiter due to a very high phase angle? Is this phase angle going to significantly drop to allow distant NH ALICE measurements or am I not seeing something?

EDIT: Just checked the Solar System Simulator, phase angle will remain a whopping 174 degrees until the end of april and only drop to 170 at end of june. That seems too dangerous for comfort.

I'm REALLY not familliar with the program, but I'm guessing that NH is looking at the
magnetotail now and not Jupiter itself, so the instrument does not have to point at Jupiter.

edit: But come to think of it, how does a spectrometer look at a magnetotail?

edit #2: Or maybe NH is not using its Alice at this point, studying the magnetotail
with other instruments while Rosetta uses its Alice.

From: http://www.physorg.com/news92058084.html

"We couldn't pass up this opportunity to study Jupiter's meteorology, rings, aurorae, satellites, and magnetosphere," says Alan Stern, Southwest Research Institute, Colorado, and New Horizon's Principal Investigator....

The idea for the joint observations came from Stern. As well as leading New Horizons, he is also the principal investigator for Rosetta's ALICE instrument.

ALICE is the ultraviolet imaging spectrometer. Designed to analyse gases being given off by Rosetta's target comet....

Rosetta will study Jupiter for between 6 and 8 days in total, spread over the next few weeks. Each time Rosetta opens its eyes to look at Jupiter, it will do so for several hours at a time, collecting as much light from the faraway planet as possible. "Rosetta will give us the big picture context in which to see the up-close data from New Horizons," says Stern. During this time, New Horizons will be riding the long tail of magnetism that stretches out behind Jupiter and funnels charged particles away.

Rosetta's ALICE was the prototype for the ultraviolet imaging instrument flying on New Horizons.....

Note the newly posted (with temporary free online access) special issue of Space Science Reviews (Numbers 1-4/February, 2007) - Rosetta: Mission to Comet 67P/Churyumov-Gerasimenko, which contains 33 articles.

I ran some simulations using xplanet with the latest spice kernels from the NAIF site, and according to this, closest approach will be on november 13, 11 pm UTC at a distance of 380.000 km

With a narrow angle camera view of 2.35 degrees and a camera resolution of 2048x2048 this would look like this:

Click to view attachment

(camera specs found here

It's a shame the perspective is so, well, earthlike.

The PDS announced a few days ago the first release of ALICE data from Rosetta.
I don't know if there's anything in here worth messing around with, but it seems worth a look...

--Emily

Waddayaknow - Alan and his team deliver the goodies nice and early. Meanwhile the European lot drag their feet.

Not sure how 'suitable for public consumption' Alice data is, but I'll certainly have a look at some point

Doug

Is there some other data for us to look at?
No, now go away or I shall taunt you a second time.

Split posts to Rosetta flyby of Asteroid Steins

I was hunting around today for basic information on the specs of the Rosetta navigation camera and came up pretty much empty except for the caption of the Earth flyby pictures, which state that an image of 820 by 820 pixels corresponds to a FOV of 4 degrees. Can anyone point me to a link with any more official information on detector size or FOV or angular resolution or any of that stuff?

--Emily

The field of view is about 5 degrees, pixel scale 0.005 degree/pixel (18 arcsec/pixel), no filters.
Sorry, I don't know of any website or publication I could point you to.

Galileo Avionica

All credit to the RPC-IES team for delivering to the PDS - what we really want is Osiris and CIVA though

Acronym overload!!!

Thank you very much! I knew if I asked here someone would come through.

--Emily

It is worth noting that over the weekend Hubble studied Lutetia with WFPC/2 and SBC to characterize it in UV. It also did visible band imaging which included a detailed satellite search. I look forward to seeing the results of this - wow, a moonlet would be cool.

http://archive.stsci.edu/proposal_search.p...st&id=11957

http://www.stsci.edu/observing/phase2-public/11957.pro

Today on arXiv Spitzer Observations of Comet 67P/Churyumov-Gerasimenko at 5.5-4.3 AU From the Sun note that Spitzer has also made observations of EPOXI's target Hartley 2, but there is nothing published about it yet.
Also note that a paper titled New visible spectra and mineralogical assessment of 21 Lutetia, a target of Rosetta mission is forthcoming in Astronomy & Astrophysics

That paper has now been published

Some news about Steins on the french agency site :
http://www.cnes.fr/web/CNES-en/7806-gp-ste...its-secrets.php

Interesting information about the string of craters.

Speaking of which, any idea of when results of the Steins flyby are going to get published in the refereed literature?

I knew those craters had to be related, and not just a trick of shadows.

I'm not convinced. Remember the great north-south chain of large craters down the central meridian of our moon? Invoked as evidence of internal processes, now ignored. But for the record, check out the other image in that story - it has a similar chain running left to right across it.

Phil

Coming back to the line of craters again - I've already said that I think the craters appear to have different ages - some more subdued than others. Another reason I'm not convinced by this interpretation (drainage of regolith into a fracture, as suggested for Phobos) is that the scale is wrong. A little world, a little crater, I'd expect to see a little crack (if any) and really tiny pits. In fact I think such pits, if they did form on Steins, would be too small to be resolved in Rosetta images. This is like the Valles Marineris of Steins. I believe this is just a random set of craters that appear to be in line in this view, but if you look at the full image sequence you can make out other apparent lines as well, including one that re-uses some of these craters when relief distortions change the apparent alignment.

Phil

Alignments are not just apparent. When you change the angle at which you view the body, you change the faces on that body that are in the way of a stream of impactors. If you rotate Steins to a variety of angles, you can line up any number of craters into potential chains.

I think one or two of those craters look suspiciously like sinkholes, and there could well be internal faulting that is causing some of the observed cratering. However, the small but significant size differences, the weathering and appearance differences, and especially the depth differences in the craters in this little chain tell me that at least some of them are impact craters made by somewhat different types of impacts (bigger and smaller impactors, differences in relative velocity, etc.).

When you look closely at the Real World, observed phenomenon are usually the results of blends of causes, not of nice, tidy, neat, this-explains-it-all processes. If two different processes are possible, rest assured that, to one degree or another, the results of both of those processes will be observed.

-the other Doug

The Rosetta blog is back, baby. Gearing up for next month's Earth fly-by.

The Blog is at logically named:

http://webservices.esa.int/blog/blog/5

The updates will probably be slow for the next couple weeks. The most recent post:
On Friday, 13 November, 2009, at 07:46 UT, ESA's Rosetta satellite will make her third (and final) swing-by of Earth, picking up a gravity assist from our bulky home planet and altering trajectory as she enters the next stages of the 10-year journey to Comet 67 P/Churyumov-Gerasimenko.

The ESA Flight Dynamics team have predicted Rosetta's altitude at the point of closest approach (perigee height) on 13 November to be 2481 km, slightly higher than her first swing-by in March 2005 (1954 km) and lower than her second swing-by on 13 November 2007 (5295 km). We'll update this figure as we get closer to the swing-by date itself...

The geographical point of closest approach (the point on the Earth's surface over which she'll make closest approach) is 109°E and 8°S - just off the coast of the Indonesian island of Java.

Thanks for the reminder ... need to update the trajectory in my simulations a little!

EDIT: done

8 November Moon image is up

Some interesting observations are planned for the flyby
http://sci.esa.int/science-e/www/object/in...fobjectid=45865
Note in particular the 24-hour "movie" of the approaching Earth (please ESA don't mess up and release it!) and the attempt to detect water on the surface of the Moon.

Doesn't say how many frames will actually be captured, but... YES!!!11eleven

Let's just hope they flip it the right way 'round before releasing it this time

I'll settle with them releasing it. One can always flip it afterwards.

Osiris is a STUNNING instrument - 2kx2k CCD - can't wait to see what they come up with.

I just wish they'd release the data from previous flybys etc.

Yes, there have been nothing more about Steins since last year. And nothing has been published in the literature yet

Absolutely beautiful view of Earth... http://www.esa.int/esaCP/SEMXJY3VU1G_index_0.html

Whoa! That's a stunner of a pic, all right. We do have a nice little piece of real estate with curb appeal, don't we?