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

Rosetta's first opportunity to listen out for Philae is now over, but the lander has not yet reported back. The next attempt is planned for April. Find out more in the latest status report from the lander teams:

Waiting patiently for Philae

For the past eight days, Rosetta has been sending signals to Philae and listening for a response, but the lander has not yet reported back. This report is provided by the German Aerospace Center, DLR.

Perhaps it is still too cold for the Philae lander to wake up on Comet 67P/Churyumov-Gerasimenko. Maybe its power resources are not yet sufficient to send a signal to the team at the DLR Lander Control Center. On 12 March 2015, the Rosetta orbiter began to send signals to the lander and listen for a response, but Philae has not yet reported back.

“It was a very early attempt; we will repeat this process until we receive a response from Philae,” says DLR Project Manager Stephan Ulamec. “We have to be patient.”

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find out more.... here:
[link to blogs.esa.int]

Another great view of Comet 67P/C-G from 14 March 2015

CometWatch 14 March – 6 hours later

This single frame NAVCAM image was taken on 14 March at a distance of 81.4 km from the centre of Comet 67P/Churyumov-Gerasimenko. At this distance, the resolution of NAVCAM is 7.3 m/pixel. The image is cropped and measures 6.4 × 5.9 km (the original picture, uncropped, is provided at the end of the post and measures 7.1 km across).

more here:
[link to blogs.esa.int]

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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[link to blogs.esa.int]

Cold formation

Some more evidence of the conditions of comet 67P formation has been published in the Journal Science. The paper from the ROSINA team concerns the quantity and isotopic ratios of molecular nitrogen gas. Molecular nitrogen has never been recorded at a comet before, ScienceDaily describing it as the "most wanted molecule" [link to www.sciencedaily.com]

Comets, are relatively sparse in molecular nitrogen, one of the most common gasses in the proto-solar nebula. Two possible mechanisms are suggested to explain this low number but both point towards cometary grains forming at extremely low temperatures. In the abstract to the article, Martin Rubin, says "This depletion suggests that cometary grains formed at low temperature conditions below ~30 K"

[link to www.sciencemag.org]

One further conclusion drawn in the paper is that the isotopic ratios of nitrogen in comet 67P makes Jupiter class comets a less likely source of the nitrogen on Earth.

blog entry
[link to blogs.esa.int]

K

Rosetta shakedown

Here is Rosetta going through the closest you can get to a shakedown test on Earth. Rosetta is inside ESTEC's Large Space Simulator vacuum chamber during a thermal test run.

[link to rosetta.jpl.nasa.gov]

The blue object on the left is the Sun. Here casting Rosetta's shadow. ESTEC can turn the sun from deep space up to Earth/Moon ( 1360 W/m^2 ) and on to Venus ( 2600 W/m^2 )

[link to rosetta.jpl.nasa.gov]

ESTEC, the European Space Research and Technology Centre (ESTEC) in Noordwijk, the Netherlands did all the pre-flight testing on the assembled spacecraft prior to flight.

You can explore ESTEC and the Large Space Simulator here.
[link to esamultimedia.esa.int]

K

NAVCAM 18th March

Here is a stretched NAVCAM shot looking directly at the Hatmehit crater, wherePhilae was last seen. Jet activity continues over the sunlit side.

NAVCAM from 81 km 6.9M/pixel
[link to www.esa.int]

blog post
[link to blogs.esa.int]

K

Accomazzo

I'm glad the Royal aeronautical society uploaded this one as the lecture sold out quickly.



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

I haven't had a chance to watch this talk given by ESA spacecraft operations manager and Rosetta flight director, Andrea Accomazzo. Accomazzo, a former Italian air force pilot and aeronautical engineer has never been known to wear an inappropriate shirt.

K

NAVCAM 20th March

NAVCAM 82km 7m/pixel
[link to www.esa.int]

Here is a view of the Imhotep region ( the foot ). I always thought this was the most Earth like landscape with its broad dusty boulder strew plains bounded by short cliffs, like some extraterrestrial Lanzarote.

Have a look at the blog, Emily Baldwin puts the recent close fly by pictures into their geographic ( cometographic ? ) context.
[link to blogs.esa.int]

K

Galleries

This is a nice feature I hadn't come across before. ESA have organised their pictures into collections of the the best quality or most interesting images. Here is the index page.

[link to sci.esa.int]

K

Euronews update

Here is Euronew's latest on the Rosetta mission and the hopes for Philae's revival.



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

K

NAVCAM 21st March

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


This image accompanies a blog post called "Around Anubis and Atum" [link to blogs.esa.int] the team has put some of the older NAVCAM shots in context to highlight some close up views. It's a shame Rosetta can't get that close any more in a bound orbit. We just have to wait now for the release of the next batch of OSIRIS pictures for a *really* close view.

K

CometWatch 22 March

This single frame Rosetta Navigation Camera image was taken on 22 March 2015 at a distance of 77.8 km from the centre of Comet 67P/C-G. The image scale is 6.6 m/pixel and the 1024 x 1024 pixel image measures 6.8 km across.

picture

Cropped and processed single frame NAVCAM image of Comet 67P/C-G taken on 22 March 2015 from a distance of 77.8 km to the comet centre. The processed image is cropped and measures 6 x 6 km. Credits: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0

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

Wow, another ‪#‎awesome‬ image from the Rosetta Mission NAVCAM, taken on 21 March at 82.6 km from the centre of Comet 67P/Churyumov-Gerasimenko. The image is cropped and processed to bring out the details of the comet's activity.

Go to link for more details:
[link to www.esa.int]

Stunning 3D Spins

Many of you will remember the talented 3D graphics artists and VFX director Mattias Malmer from his previous 3D renderings of comet 67P. His work has even been "borrowed" ( with credit given ) by various members of the Rosetta team in order to illustrate a point. His depth cued picture of Philaes' surroundings springs to mind here. [link to mattias.malmer.nu]

Now Mattias has excelled himself again with a set of stunning 3D rendered rotations of the comet, complete with colourisation and jets. They were produced for Dr Joel Parker the ALICE PI for use in a public talk. As ever with Mattias' work, these animations are best appreciated full screen HD on the biggest screen you have.



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



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

and without dust jets..



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



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

These are so good considering Mattias only had access to the images in the public domain; the featured NAVCAM shots and handful of OSIRIS images. He had to develop his own shape model to drape the images over, amazing work. The only problem now is that GLPers will start saying " see I told you it was all faked in a computer"

Mattias' blog is here
[link to mattias.malmer.nu]

K

The latest set of NAVCAMs have now been added to this archive. There are some nice images of the close approach now. Have a look at this lovely animation of the comet rotating as Rosetta's closes in. It may lack the full screen beauty of Malmer's CGI, but this is the real thing.

[link to blogs.esa.int]

The new collection of 213 images is here [link to imagearchives.esac.esa.int] ( MTP005 ) Images are available in FITS format.

K

( Nearly ) Lost in Space

Andrea Accomazzo's hotdogging low pass over the surface of the comet recently resulted in a temporary loss of communication and navigation from Rosetta.

During its most recent close flyby last Saturday, where Rosetta flew within 14 km of the surface of the comet, the spacecraft experienced significant difficulties in navigation. This resulted in its high gain antenna starting to drift away from pointing at the Earth, impacting communications, and was subsequently followed by a ‘safe mode’ event. The spacecraft has now been successfully recovered, but it will take a little longer to resume normal scientific operations. Here is the full report from the mission team:

The problems started when the star trackers became confused. You see star trackers are a great idea for orienting and navigating spacecraft, except when your field of view is full of thousands of tiny, bright, white objects flying around in random directions, like you might find close to an active comet nucleus.

During the most recent flyby, a number of issues were reported, starting with the primary star tracker encountering difficulties in locking on to stars on the way in towards closest approach. Attempts were made to regain tracking capabilities, but there was too much background noise due to activity close to the comet nucleus: hundreds of ‘false stars’ were registered and it took almost 24 hours before tracking was properly re-established.

Do you think they said "My God it's full of stars"?



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

Blog post here.
[link to blogs.esa.int]

K

Close fly-by NAVCAM images

Stunning NAVCAM 28th March 20km 1.7m/pixel
[link to www.esa.int]

I still get blow away by images like that. A tiny world, only 4 km long, 420 million km away [link to theskylive.com] but there is something familiar about the landscape, like the frost shattered peaks of Northern Britain and Wales.

There are some more stunning close NAVCAMS from the same blog post.
[link to blogs.esa.int]

K

Just a reminder to anyone who may have forgotten there is an excellent web-GL simulation that runs in web browsers to visualise where Rosetta is right now ( and where it is going ) called erm "where is Rosetta"

[link to sci.esa.int]

K

ESA, this week in pictures


[link to www.esa.int]

happy Easter

K

Landing again

I have just found this Youtube of the landing day as it happened. A bit of fast forwarding revealed the money shot happens at 05:06:40



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

K

Ceres next

Here is a quick reminder of when we get the next Ceres images.


The next optical navigation images of Ceres will be taken on April 10th and April 14th, and are expected to be available online after initial analysis by the science team. In the first of these, the dwarf planet will appear as a thin crescent, much like the images taken on March 1st, but with about 1.5 times higher resolution. The April 14th images will reveal a slightly larger crescent in even greater detail.
[link to astronomynow.com]

So the next great image may be around April 17th.

K

"Expect the unexpected!" – ESA TV update on the Rosetta Mission's surprising science discoveries at Comet 67P/Churyumov-Gerasimenko:

Video:
Published on Apr 8, 2015
Each day the Rosetta spacecraft collects new information about comet 67P/Churyumov-Gerasimenko. This data is sent daily across deep space to scientists all over Europe including those at the University of Bern, in Switzerland, where Rosetta’s ROSINA instrument was built to analyse the comet’s atmosphere.



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



note: I will be away from the Internet 14 April/14 May. Will not be able to update the thread during that time.

Near and far – CometWatch 28 March-2 April

CometWatch is back with two images, to offer a taste of Rosetta's trajectory in the past couple of weeks.

The first of today's entries is a 2x2 montage of NAVCAM images obtained on Saturday 28 March from a distance of 31.3 km from the centre of Comet 67P/Churyumov-Gerasimenko. These images were taken as Rosetta departed from the comet, almost seven hours after its close flyby 14 km from the surface of 67P/C-G.

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

Calling All GLP Astronomers

NASA needs you!

[link to cdn.skyatnightmagazine.com]


"Are you an amateur astronomer? The Rosetta mission has an opportunity for you, one that will allow you to collaborate with professional astronomers and study a comet in tandem with a real space mission."
[link to rosetta.jpl.nasa.gov]

This is a reminder that the Rosetta ground based campaign to observe comet 67P has started. Here is the page you need [link to rosetta.jpl.nasa.gov]

If you have access to a sufficiently large telescope, you could be the first to image an outburst or a change in the appearance of the tails. 67P will be a pretty faint comet so NASA are suggesting that to participate in the campaign you will need at least a 14-inch telescope.

K

Even with the Rosetta Mission's new trajectory scheme, the orbiter will still be able to listen out for Philae, in case it wakes up from hibernation in the coming weeks or months.

Next listening opportunities for Philae

Based on the latest report published by the German Aerospace Centre.

Despite Rosetta’s new trajectory scheme, the orbiter is still able to listen out for its lander Philae, in case it has woken up from hibernation. Thus a new listening window opens on Sunday, 12 April.

“The communication unit on the orbiter will be turned on around the clock,” says Dr Stephan Ulamec, lander manager at DLR. “Most likely, Philae will wake up in May or June, but we don’t want to miss the moment if it should have enough energy and a sufficiently high operating temperature to wake up earlier.”

To wake up and listen for signals from Rosetta, Philae must have at least 5.5 watts and an operating temperature above –45 degrees Celsius. With a bit more energy, around 19 watts, Philae would be able to return the ‘call’.

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

NAVCAM 8th April

NAVCAM from 137km 12m/pixel Imhotep region
[link to www.esa.int]

A lovely view of the jets emanating from the sun lit Imhotep region as Rosetta re-establishes it's planned trajectory.
[link to blogs.esa.int]

I'm a bit behind with the Rosetta news, I will try to get a good round up this week coming. We may also see a new view of the crescent of Ceres by the end of the week.

K

New GIADA paper

The Rosetta blog has some details of a new paper published by the GIADA team. The last update I had on the Grain Impact Analyser and Duset Accumulator was here, Thread: Rosetta Comet Orbiter -** 120 Icy Patches ** Philae Phones Home ** Ceres Fly Over Video ** New Coma Discovery ** Picture MOTHER LODE ! (Page 58) . The paper concerns the properties of the "fluffy particles" picked up in the detector. You may remember that the COSIMA team talked about the different populations of dust particles Thread: Rosetta Comet Orbiter -** 120 Icy Patches ** Philae Phones Home ** Ceres Fly Over Video ** New Coma Discovery ** Picture MOTHER LODE ! (Page 58) and Thread: Rosetta Comet Orbiter -** 120 Icy Patches ** Philae Phones Home ** Ceres Fly Over Video ** New Coma Discovery ** Picture MOTHER LODE ! (Page 59)

Marco Fulle, the GIADA PI has been outlining some of the key differences in the two main populations of dust. The compact solid grains are believed to be material that has been processed in the hot environment around the newly ignited Sun. Their densities range from 0.8 to 3 g.cm-3, consistent with the ices and minerals which make up the comet. The fluffy particles on the other hand are believed to originate in the interstellar cloud and pre-date our solar system. Their densities are as low as 0.001 g.cm-3 which Fulle likens to a dandelion seed head.

This low density has an effect on the velocity of the grains in GIADA. Currently Rosetta's potential varies between -5V and -10V depending where it is in it's orbit. The photo-ionisation of water in the jets creates clouds of electrons which impact Rosetta and drive it's potential into negative values. There is an opposing process of the photo-electric effect from solar UV driving Rosetta's potential to small positive values but at the moment the electrons are winning the battle, it is particularly noticeable how the potential is driven to more negative values when the COPS pressure sensor detects the densest jets. The negative spacecraft potential and similar negative potential on the fluffy grains has the effect of slowing them in the GIADA instrument ( and may even be repelling some ) skewing the results.

blog entry here.
[link to blogs.esa.int]

K

Ceres Latest

We are still on track to see a new higher resolution picture of Ceres by the end of this week from last Friday's OpNav 6. The OpNav 6 will only show the dwarf planet as a crescent. Next week we will see a higher resolution image of half the world following Dawn's optical navigation imaging of Ceres tomorrow ( OpNav 7).

NASA/JPL have released a false colour image of the last RC image ( two bright spots ).

[link to dawn.jpl.nasa.gov]

For some reason ( maybe for clarity, maybe aesthetic ) they have reversed the colour channels so that the real life blue image has the red channel in the image and the infrared channel is shown as blue in the image.

blog entry
[link to dawn.jpl.nasa.gov]

K

Listening for Philae

Rosetta is once again well positioned to listen for a signal from Philae. The lander is not expected to be able to reply until May or June, when the batteries have warmed enough to begin charging. For now the hope is that Philae's may be able to receive the commands sent from Rosetta to optimise the heating of the batteries and optimise transmitter use.

Philae's transmitter draws more power than can be directly supplied from its PV cells. In order to transmit back to Rosetta, Philae needs to warm its batteries to above freezing point so that they can begin charging. For now it is thought that there is insufficient power being delivered to the battery heaters to do this because of the limited amount of light falling on Philae's PV panels.

blog
[link to blogs.esa.int]

K

Interesting paper, which can be found in full here:
[link to iopscience.iop.org]

On another note, we can only hope that Philae is slowly warming...or receiving anything.