Rosetta Comet Orbiter -** 120 Icy Patches ** Philae Phones Home ** Ceres Fly Over Video ** New Coma Discovery ** Picture MOTHER LODE !

Dawn Ceres Briefing

Here is the press briefing NASA held about the Dawn spacecraft at Ceres. I haven't been able to watch all of it yet but it looks interesting. What I have seen is that they are still thinking that CERES has a water ice mantle and that the large fractured basin ( death star crater ) supports this hypothesis. Are there too many large craters on the equator, is the ice mantle partial ? We will find out over the next fascinating year.



[link to www.youtube.com (secure)]

F-BVFA, I can't reply to pm ( not a member ). It's a shame but the running costs look high and some of its work can be done by ALMA now and in the near future ( hopefully ) JWST will be even more capable than SOFIA.

K

Thank you for your GKP and reply. My mailbox will expire in the coming days too.

This is some interesting information regarding SOFIA. I need to look into ALMA more and JWST. I will have to send an email to somebody over in the U.S. who is tied to SOFIA for confirmation.

What is JWST if I may ask?

We need more like you on this board. I would give you a lifetime complimentary membership if I was the owner.

NAVCAM 26 February

NAVCAM 8m per pixel from 96km
[link to www.esa.int]

A different view of the jets of the major lobe. The blog has produced a handy annotated version of the picture.

[link to blogs.esa.int]

The cliffs of Hathor, sounds like a good title for a fantasy novel.

Here is the blog post
[link to blogs.esa.int]

RE Spacecraft shadows. Rosetta is not the first spacecraft to image its own shadow. Here is a picture of Hayabusa I ( now that we have a Hayabusa II ) shadow on the asteroid Itokawa.
[link to solarsystem.nasa.gov]

K

Thanks for the compliment but I just come here for my own fun and amusement, I don't have any great mission.




The James Webb space telescope is the next great space telescope after Hubble. Its segmented primary mirror is about 5 times the area of Hubble's. Its mission will be to look at older and colder things than Hubble is capable of. As you look further away there is a greater red shift effect so to see the oldest galaxies, furthest from Earth you need a telescope that can look into the mid infra-red and beyond. Hubble can see from near infra-red through visible and into ultra violet. JWST will see from mid infra-red up to orange light. SOFIA overlaps ALMA and JWST in its capability. JWST will also be looking at cold gas clouds and planet formation.

You can watch it being built here.
[link to www.jwst.nasa.gov]

It's run into a lot of problems with cost escalation and threat of cancellation but it looks like it will be launched in 2018 on an Ariane 5, is there any other heavy lifter ? ;)

There is lots of European input into JWST. A team coordinated by ESA at ESTEC is building the Near InfraRed Spectrograph (NIRSpec) and the mid infra-red spectrometer MIRI is being built with a lot of input from the UK ( UK AST , Imperial, RAL ) and other European research institutes.

[link to www.stfc.ac.uk]

K

Jet Quartet

Here is a nice quartet of images showing that the jet activity extends over all the sunlit faces of the comet now.
[link to blogs.esa.int]

The images were actually gathered to help the ALICE instrument relate its results to the area of nucleus it was investigating

blog post
[link to blogs.esa.int]


In this image
[link to www.esa.int]

We can see a streak between the lobes. My understanding is this is likely to be a particle in the foreground of the image. A cosmic ray strike would be "jagged" with a sharp outline and even intensity along its length. Any astro-photographers like to offer an experts opinion ?

K

New NAVCAM browser

Great news for NAVCAM fans, now you can watch a small dot slowly approaching over a period of months !

Actually it's a lot better than that, a team from ESAC has put together a NAVCAM browser tool so over the coming months you will be able to see all the NAVCAM shots taken last year. So far we only have the far approach phase, which isn't all that interesting, unless you are a fan of small dots or are practising to be a flight director. Next month it will start to get interesting.

[link to imagearchives.esac.esa.int]

This tool is in addiction to ESA's Planetary Science Archive where you can find all the mission data that is no longer in the propriety period. Holger Sierks, when asked to contribute recent OSIRIS images to the archive, said "From my cold dead hands!" which is an improvement on the current situation.

You can browse the archive here, OSIRIS images are pre-hibernation.
[link to www.sciops.esa.int]

Moody OSIRIS image of Lutetia ( cut + paste address into a new tab )
ftp://psa.esac.esa.int/pub/mirror/INTERNATIONAL-ROSETTA-MISSI​ON/OSINAC/RO-A-OSINAC-2-AST2-LUTETIAFLYBY-V1.1/BROWSE/2010_07​/N20100710T154749351ID20F16.JPG

blog post
[link to blogs.esa.int]

K

Gresham lecture part one and two

The videos from the first two parts of the Gresham college lecture are up on the website.

[link to www.gresham.ac.uk]

An introduction to Rosetta - both the stone and the European Space Agency mission - and to the life's work of Colin Pillinger, who inspired the connection. - Professor Ian Wright. He is the Ptolemy PI. You are probably used to seeing him like this [link to pbs.twimg.com (secure)] but recently he looked like this [link to pbs.twimg.com (secure)]

I really enjoyed this part, all about Egyptology and the Rosetta stone.

[link to www.gresham.ac.uk]

from Professor Richard Parkinson.

K

NAVCAM 28th February

NAVCAM 8.7 m/pixel
[link to www.esa.int]

Here is the comet from around 103km. Lots of nice jet activity from this perspective and curvature of the jets

K

Full Ceres Rotation

Here is a nice little animated giff of the RC2 rotational characterisation imaging run. The RCs help the Dawn flight dynamics people plan for future close orbits of Dawn.

[link to dawn.jpl.nasa.gov]

Anyone waiting for a mysterious "dark side" of Ceres is going to be disappointed as there isn't one, this tiny dwarf planet rotates in around 9 hours. Dawn is currently on the far side of Ceres and will be until some time next month. This is because the gravitational capture manoeuvre for Dawn is much slower and more difficult than it was for Rosetta, despite Ceres much greater gravitational field. Dawn only has a tiny amount of thrust available from its ion engine so it is forced to fly long orbital legs to get into position.



[link to www.youtube.com (secure)]

K

Rosetta - Matt Taylor - Gresham lecture part three

[link to www.gresham.ac.uk]

At the time I thought it was a bit too rushed and I was disappointed there were few new insights revealed. Looking at it again it's actually a great whistle stop summary of the whole mission to date. Well worth watching if you are new to Rosetta.

K

Rosetta has some opportunities coming up to listen out for Philae. Find out more in the latest status report from the lander teams:

Waiting for a signal from Philae

This week, Rosetta will begin listening for signs that Philae is still “alive”. This report is provided by the German Aerospace Center, DLR.

It would be very lucky if a signal were to be received from Philae at 05:00 CET on 12 March 2015. The lander finally came to rest on 12 November 2014 in a rather shaded location on Comet 67P/Churyumov-Gerasimenko and it needs to receive sufficient energy before it can wake up and begin communicating. This is, however, the first possibility to receive a signal from Philae; therefore, the communication unit on the Rosetta orbiter will be switched on to call the lander.

“Philae currently receives about twice as much solar energy as it did in November last year,” says Lander Project Manager Stephan Ulamec from the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR).

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read more + pictures here:
[link to blogs.esa.int]




Last Edited by Concorde Warrior F-BVFA on 03/11/2015 01:49 PM

Philae’s instruments (white background)

[link to www.esa.int]

[link to www.youtube.com (secure)]

Philae is not calling home this morning it seems.

K

Ceres Crescent

Here are the latest images of Ceres from the Dawn mission, two nice views of a crescent Ceres taken during OpNav 5. don't ask me what happened to the superior OpNav 4 images, I'm guessing that they were lost in all the Ceres news. That or the alien lightning base headlights they showed ;)

OpNav5 48,000 km 2.9 km /pixel (1)
[link to dawn.jpl.nasa.gov]

OpNav5 48,000 km 2.9 km /pixel (2)
[link to dawn.jpl.nasa.gov]

The next notable images of Ceres will come a few days after the 15th April with the OpNav7 images, roughly twice the resolution of these pictures.

K

This great shot of Comet 67P/Churyumov-Gerasimenko from 9 March not only shows off the comet's activity, but also provides a clearer view of features that in many previously published images have been partly cast in shadow.

Today’s CometWatch entry was captured on 9 March at a distance of 71.9 km from the centre of Comet 67P/Churyumov-Gerasimenko.

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more text and pictures here:
[link to blogs.esa.int]

There is still plenty of science for Rosetta to do from orbit, such as this OSIRIS reflectivity study, which hints at ice in the comet's neck region:

OSIRIS detects hints of ice in comet’s neck

This post is based on information provided by the OSIRIS team at the Max Planck Institute for Solar System Research (MPS) in Germany.

If it could be seen with the naked human eye, the nucleus of Comet 67P/Churyumov-Gerasimenko would be a dark grey all over. With its array of specialised filters, however, Rosetta’s scientific imaging system OSIRIS can discern tiny differences in reflectivity at different wavelengths across the comet’s surface. In turn, these differences can reveal clues as to the local composition of the comet.

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more text and images here:
[link to blogs.esa.int]

That's a great new colour image.
[link to www.esa.int]

The VIRTIS people have been saying for some months now that they were seeing ice mixed in with the material in the Hapi ( neck ) region, it's nice to see OSIRIS confirming that finding.

If you look at the major lobe over on the right you can also see some of the blue in the cliff faces, rather like VIRTIS found on cliffs of the Imhotep region previously. [link to i.imgur.com] There also seem to be some blue detached boulders at the foot of those faces rather like this previous set of OSIRIS images [link to www.esa.int]

I wonder how much more exposed ice we will see over th coming six months ?

K

From my viewing experience of color stretched images of the Viking Orbiter around Mars the colors we are seeing on the color space stretched Osiris images are only caused by polarization or other optical effects within the camera itself. If you apply color stretching on Viking Orbiter Images, one side of the frame appear blueish and the other reddish.

My guess is, that the color filters could have been degraded by the long exposure to ionization radiation in space over the 7 years of travel since the Rosetta 2007 Mars flyby.

Hi McKracken, interesting coments.


Not too sure about the blue, I know that there is a known grain size effect for dust in the micron size range to give a red hue to small bodies like astreroids and moons due to selective scattering. [link to blogs.esa.int]


That is something you may see with a degraded instrument, but look again at the OSIRIS images, the blue is localised to particular, often small, features such as boulders, cliff faces and the regolith in the Hapi region. A general blue hue would surely be spread across the image independently of the featured subject.


OSIRIS has a comprehensive suite of in flight calibration tests including relative spectral response, page 36 of this document outlines them. The instrument was designed to perform for over ten years in the environment it's in, so it has extra radiation shielding, carries spare calibration lamps and can perform periodic annealing of the CCD to maintain performance. [link to pdssbn.astro.umd.edu]

I think the important thing about the blog entry is that OSIRIS has now confirmed the same result that VIRTIS, the visual and infra red spectrometer - a much more accurate instrument, had found. The VIRTIS team found that the regolith in the Hapi region would have to contain ( at the time they measured it ) between 0.5% and 1% water ice mixed in with dust of the regolith layer in order to account the the distinctive absorption spectra they were looking at. VIRTIS has also seen the unmistakeable signature of exposed water ice in the cliffs of the Imhotep region. [link to i.imgur.com]

Altogether it shouldn't be a surprise to find dust and ice on the surface of an object that is ejecting large quantities of both into its coma.

K

Very interesting document! The degradation of the color filters was tested by stressing them with proton beams. Though flat field images with the internal calibration lamp should reveal if actual in-flight degradation happened.

The effects I was speaking of are those, which are also appearing on the THEMIS images from Mars Odyssey:

[link to themis.asu.edu]
[link to themis.asu.edu]
[link to themis.asu.edu]
[link to themis.asu.edu]

It's engineering porn ;)



Yes, two orders of magnitude higher radiant exposure than is expected on the mission. They also found that "annealing at room temperature causes a rapid recovery towards the initial transmission" when OSIRIS is not operating its temperature can float as high as 70 C ( although it won't be that high in this part of the mission )


I thought the flat fielding was to show variations / defects in the CCD. The design of the cameras would allow calibration to be done with a filter in position, the light frame is generated from the calibration lamps diffuse reflection from the inside of the camera's door. Dr Astro and other astrophotographers could better answer whether flat fields would be generated for all the filters. The question of whether the filters have "faded" or changed in spectral properties would be better answered by the relative spectral response calibration where stars of known spectral type are imaged by OSIRIS.



I don't know about the first two images, I will leave those aside. The last two look like something I have seen with OSIRIS images. The team have spoken about the difficulty in aligning the different filter images from slightly different perspectives as the spacecraft moves. Here is one they did a lot of aligning compensation on.

[link to www.esa.int]

Compare to this different, more stretched image with colour mottling. Is this an alignment issue or maybe an artefact from the colour saturation process?

[link to univ.smugmug.com]

K

On Mars Odyssey no alignment problems between each color channel exists as all channels are exposed at the same time. There are two problems on Mars Odyssey: 1. the color variances within one line, with much error on the left and right borders. Those might be caused by reflection within the camera optics or by the incidence angle of the light against the filter or against the CCD. 2. the color variance throughout the image where at some location the uniform sand surface appears more blueish and then more reddish. I don't mean the really colored blue areas in some craters those do exists on the surface and are known from other satellites' images.

The colors in the very last Osiris image on your lasts post are all caused by non-aligned channels combined with lossy image compression.

The reason I'm responding here: I'm surprised how observations about water or water ice are now presented. It appears as it is of such importance to present any water or ice that grasping at straws is done now :-)

I wondered why you were so keen to find any possibility other than water for the OSIRIS images, I guess you are one of those "it's a rock" people.

The fact is that apart from a handful of people who have been taken in by a scam organisation, nobody is attempting to prove or disprove that comets are full of ices. The rest of the world ( or the part that is interested ) has seen for itself the wealth of information about cometary water and ices that has come from Rosetta and previous missions.

Out beyond the frost line, beyond the orbit of Mars where comets form, the most common solid building materials are ices. The gas giants contain large amounts of ice, their large moons are made of ice. Uranus and Neptune each contain enough ice to fill the Pacific ocean 100,000,000,000 times over. The Kuiper belt objects are mostly ice. If comets contained no ice it would be astonishing, so it was no surprise when all of Rosetta's and Philae's instruments that could detect water or ice or the action of water, all found water or ice.

There are plenty of questions to be answered about comets by Rosetta, like how does the thermal transportation mechanism work, what do the subsurface structures look like and has a new phase of ice been discovered but the question "is there water" has been answered in the affirmative many times over.

K

Great shot of boulders strewn about on the neck of Comet 67P/C-G from 17 October 2014, when Rosetta was only 10 km from the comet's centre.


CometWatch: Focus on Hapi’s boulders

With today’s CometWatch entry, we take a dip into the past, presenting a single frame NAVCAM image obtained on 17 October 2014, when Rosetta was in a bound orbit around Comet 67P/Churyumov-Gerasimenko. The image was taken from a distance of 10.0 km from the centre of the comet, and at that distance, the resolution of NAVCAM is 85 cm/pixel and the full field of view spans 870 metres.

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more text + images here:
[link to blogs.esa.int]

NAVCAM 6th March

I think we missed two NAVCAMs last week

NAVCAM form 83 km 7m / pixel
[link to www.esa.int]

Looking towards the Imhotep region ( foot )
[link to blogs.esa.int]

There is another follow on NAVCAM from 6 hours later.


K

Taylor interview

Matt Taylor has been interviewed by by Prof. Jim Al-Khalili for his series, The Life scientific ( [link to www.bbc.co.uk] )

You should be able to listen to BBC radio iPlayer programmes outside of the UK, here is the Matt Taylor interview
[link to www.bbc.co.uk]

Dr. Taylor is still traumatised by shirtgate. Interestingly he was thinking about applying to the last astronaut call from ESA, the one that Tim Peake won. He saw that he would need to get an initial Class 1 medical certificate from the CAA ( around £350 ) and said "I could get a Playstation with that money"

K

Here it is

NAVCAM form 83 km 7m / pixel
[link to www.esa.int]

A nice illustration of the jets projecting out from the surface at all angles.

blog entry
[link to blogs.esa.int]

K

Blast from the past

How will 67P look when it reaches perihelion. Maybe a little like this.

[link to www.esa.int]

This is an image of comet 1P Halley when it was intercepted by the ESA Giotto probe on 13th March 1986. Halley has a smaller perihelion than comet 67P so 67P may not look quite this active. One popular story about that night was that after eagerly waiting to see an image of the comet on the live TV programme then being shown a false colour image like this one, [link to www.sciencephoto.com] , the British prime minister, Margeret Thatcher was so disgusted that she cut the UK's involvement in ESA and space research budgets, a decision the UK never recovered from.



[link to www.youtube.com (secure)]

K

NAVCAM 14th March

Another lovely stretched image of the nucleus showing the jets being deflected by the cliffs of Hathor.

NAVCAM 7.4m /pixel from 83km
[link to www.esa.int]

blog
[link to blogs.esa.int]

K