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

Far away, so close! Comet 67P/C-G from 226.5 km on 16 February

Imhotep from afar – CometWatch 16 February

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Today’s CometWatch entry presents a four-image mosaic comprising images taken from Rosetta's NAVCAM on 16 February from a distance of 226.5 km to the centre of the comet. The image resolution is 19.3 m/pixel and the individual 1024 x 1024 frames measure 19.8 km across. The mosaic measures 37.4 × 37.2 km.

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

Here is a great interview with Andrea Accomazzo, Rosetta flight director and the Head of the Solar and Planetary Missions Division at ESA




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

K

Dust removal

There is a very interesting post in the Rosetta blog here [link to blogs.esa.int] about the relative dust removal rates of the summer and winter ( or north and south ) hemiducks of the comet. We are currently looking at the summer or north side. During the perihelion pass the winter side of the comet will be most exposed to the Sun and will consequently lose the most dust every orbit. There is a map here showing their projections.

[link to blogs.esa.int]

The side we are looking now is expected to only lose around 5m of dust compared to 20 m for the southern hemiduck.

While we are thinking about dust removal, and we have the night time ( solar wind lee ) surface voltage, I think it would be fun to work out the largest dust particle that could be lofted 1 m above the surface by dust levitation. We don't know if dust levitation is happening, but it is hypothesised to happen on bodies such as the Moon, asteroids and comets.

K

Happy Birthday

ESA is full of birthday greetings for comet hunters. Firstly last week we had a happy birthday blog for Klim Churyumov , [link to blogs.esa.int] who discovered comet 67P on a image exposed by Svetlana Gerasimenko [link to blogs.esa.int] on the 11th September 1969, happy birthday to both !



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

K

How can Thunderbolts believe they landed an orbiter on a comet? Just confirms that Thunderbolt dolts are either as shilly as other scientists or they are just really really clueless.

NAVCAM 18th February

NAVCAM stretched image showing jets 17 m / pixel
[link to www.esa.int]

NAVCAM captured this image at 200km from the nucleus on its way back in again. For the rest of this year Rosetta will be flying these hyperbolic orbits, not gravitationally bound to the comet.



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

Blog about today's NAVCAM image
[link to blogs.esa.int]

K

Edit) Keep your eyes open for the RC2 images from Dawn, maybe we will see them today !

Manned comet landing

We are often told that comet 67P is the blackest thing you could imagine. Fred Jansen, mission manager, said it was "blacker than the blackest t-shirt you have" Nigel Tufnel said "It's like, how much more black could this be? and the answer is none. None more black." NASA 3D printed a glossy black comet that looks like it might come from a fetish shop: [link to pbs.twimg.com (secure)] not to be outdone ESA produced a giant version for Klim Churyumov to pose next to [link to blogs.esa.int]

I have been looking at this paper recently [link to onlinelibrary.wiley.com] which details some results from the Diviner radiometer on the LRO. Diviner has been measuring the Moon's albedo around an equitorial belt and has found that in general, although the Moon's overall albedo is around 0.12, the mares have an albedo of 0.07 This is not so different from the figure VIRTIS-M found found for comet 67P, which was very close to 0.06

So how might a photograph of an astronaut on a comet look, maybe like this picture of Aldrin on the Mare Tranquilis [link to upload.wikimedia.org]

K

Meh - double post - mods, please delete, thanks

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This space free to advertise the
upcoming thunderbolts conference
only $450
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K

That's no moon ! - Ceres latest

Here are the results of the 18th February RC2 imaging of the dwarf planet Ceres by the Dawn spacecraft. Resolution, 4.3 km per pixel from 46,000 km

[link to dawn.jpl.nasa.gov]

This is more or less as good as it's going to get until early April, although other images will be produced, the resolution will not be that much higher for the next month.

On the left hand image there is a shallow, non-cicular depression, with an almost symmetrical pattern of craters in it. If someone doesn't invent a good conspiracy theory about that then you all need to hand in your woowoo cards. Over on the right image there are a number of craters with bright features, is it ice ? The next imaging run is OpNav 4, which is happening today, hopefully we will see the results before the end of the week.

Read about the bright spot speculation here
[link to dawn.jpl.nasa.gov]

K

Blast from the past: on this day in 2007, Rosetta performed a flyby at Mars – one of four planetary gravity assists (the other three were at Earth) needed to boost the spacecraft onto the correct trajectory to meet up with Comet 67P/C–G. The image, taken by Philae's CIVA camera, captures one of Rosetta’s 14 m-long solar arrays set against the northern hemisphere of Mars.

Hi F-BVFA I think you fly past to quick to leave a link.

[link to www.esa.int]

This image was captured 8 years ago yesterday, just a reminder of how long we had been building up to rendezvous.

K

Thank you K. Somehow I had lost the image and could not find it again.



Tonight in London!


Rosetta: Unlocking Secrets from Ancient Egypt to a Comet
Thursday, 26 February 2015 - 6:00pm
Museum of London

Just as the Rosetta Stone and the Philae Obelisk became the key to interpreting hieroglyphs and understanding ancient Egyptian civilisation, the European Space Agency’s Rosetta probe and its Philae lander are key to furthering our understanding of the formation of our solar system, and the origins of life. The Philae lander made the first ever soft landing on a comet, opening a new chapter in Solar System exploration.

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read more here:
[link to www.gresham.ac.uk]

I think I will try and sneak off there, it sounds interesting.

A lecture arranged by the Royal Society's college, funded by the Corporation of the City of London in a theatre above the old London wall. It will be given by a professor of Egyptology, curator of hieroglyphic texts at the British Museum, a heavily tattooed plasma physicist and a recently shaven headed ex-colleague of the Gresham professor of Astronomy. The lecture will be given in honour of that astronomer and spacecraft designer who died tragically prematurely just months before his lost Mars lander was found and his comet lander was lost.

Sounds reasonable enough, if only there was some sort of conspiracy angle

K

Thanks for the tip off F-BVFA, that was very interesting, especially the Egyptology part. The lecture should go up on the Gresham College website in a few days. One thing to look out for tomorrow is the release of a memorable OSIRIS image, fingers crossed.

K

GLP went full retard over the whiter patches on Ceres, although they only noticed two of them. Good job nobody has spotted the death star crater yet

Hopefully the tip off we got yesterday is good. If it is then later today we should see an Osiris image from the close flyby with Rosetta's shadow on the surface of the nucleus !

K

Here's a previously unseen NAVCAM image from the Rosetta Mission close flyby on 14 February, and some reflections on the challenges encountered in operating in this new environment

CometWatch: The challenges of a close flyby

The image below is a single frame (1024 x 1024 pixel) NAVCAM image taken at 16:12 UT on 14 February, from a distance of about 15.3 km from the surface. The image scale is 1.3 m/pixel and the frame measures 1.3 km across. The image was taken over the Imhotep region on Comet 67P/C-G's large lobe (see the supporting images below for context).

Compare it to the frame taken at 14:19 UT to see much of the same region at a different viewing angle, as the comet rotated and spacecraft moved during the two hours between the images.

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

Historic Epic Photographs

Thread: Rosetta Spacecraft to "Harpoon" a Comet - Historic, Epic, Photographs of something Strange Indeed

Dinosaurs in Outer Space

[link to www.godlikeproductions.com]

Earth Based Photo...

Not as large as that creature, but dramatically large.

[link to static.dyp.im]

[link to static.dyp.im]

Re: The MOON photo

Crater

It really bothers me, whatever these formations are commonly referred to as "impact sites", or Craters?

Some of these are just too large to be impacts. They look more like fragments of a burst bubble of some kind?

There is a a small hole or protrusion in the center, and the area encompassed by the ring is flat, or curves with the objects surface?

I don't see how its possible these are impacts?

[link to dawn.jpl.nasa.gov]

[link to static.dyp.im]

[link to static.dyp.im]

'Cause that's what they look like.
We've seen hundreds of thousands of them by now.


Why?
The Vredefort crater right here on Earth is 300 km across.

The only upper limit to impact events would be the one where the target gets destroyed.


Plenty craters do.

There used to be (decades ago) a debate on the origin of the craters of the Moon, but there is demonstrably very little volcanism on the Moon.
The smaller the body the less one would expect volcanoes.

That's traditional volcanoes, that is.
Volcanoes that spew forth material other than molten rock is a different story.
There are known ice and sulphur volcanoes.


Lots of craters have central peaks.
Energetic enough impacts pretty much liquefy the surface.


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


As one would expect with large enough, or very old impacts.
Ceres is spherical, i.e. it has enough gravity to make the material it is made of flow into a ball shape.


Last Edited by Halcyon Dayz, FCD on 02/27/2015 01:51 PM

RAAAAAAAAAAAAAAAAARRRR !!!

K

Halcyon Dayz,FCD has covered this but these craters are interesting none the less.

[link to static.dyp.im]

The lower one here, which I had dubbed the death star crater has an interesting suture line like boundry which extends out from the crater boundry in a couple of places. This is possibly a sign of some crustal fracturing event ( probably an impact ) with a melted subsurface.

The other crater you highlighted is a large complex crater ( central peak ). This brings me to the interesting GLP exclusive about Ceres. This paper [link to www.sciencedirect.com] ( I will try and find a free version ) examined what craters would look like using the two hypothesised models of Ceres structure. The most popular current model has Ceres with a rocky core, overlain by many 10s of km of water or water ice, with a thin rocky or dusty crustal layer above. ( Edit: better image ) [link to www.dlr.de]
The other, less popular model, has Ceres as a relatively homogeneous body.

In the ice layer model, craters around the equatorial belt would be relaxed by melting of the subsurface layer driven by the Sun's energy ( insolation ). At higher latitudes, due to lower insolation ( higher angle of incidence ), craters as large as 16km across could survive. Only at the poles would we see large craters. In addition, with an icy layer, the lower size limit for complex craters is below the limit of resolution for theses images of Ceres, but we can see relatively large simple craters in the image, so -

Contrary to most expectations Ceres is a relatively homogeneous rocky body without a purely water ice mantle layer.

There is water there on Ceres, as seen by Herschel ( the telescope not the astronomer ), just not in the form of a pure ice mantle.

File this along with the first ( reasonably ) accurate measurement of comet 67P's density that you read anywhere Thread: Rosetta Comet Orbiter -** 120 Icy Patches ** Philae Phones Home ** Ceres Fly Over Video ** New Coma Discovery ** Picture MOTHER LODE ! (Page 8)

The Rosetta thread, the place to come for wild speculation that just might turn out to be true !

K

NAVCAM 20th February

NAVCAM 10m per pixel stretched image with jets from 118 km
[link to blogs.esa.int]

You can make out some of the winter "hemiduck" in this picture as it is silhouetted against the emerging coma. "As usual, background features are typically a mix of detector noise, stars, and material ejected from the comet."

NAVCAM 10m per pixel original image
[link to blogs.esa.int]

So where is this marvellous image of Rosetta's shadow on the the surface of the nucleus, well here is the next best thing.

[link to i.imgur.com]

Matt Taylor, looking at a picture of Rosetta's shadow on the nucleus I think they are still planing how to mug Holger Sierks of his laptop so they can get hold of the image themselves. Matt Taylor was wearing a long sleave shirt, covering his tattoos, under his Rosetta polo shirt. I think he has been read the riot act by the ESA PR department.

K

As an aside, today APOD is stunning: [link to apod.nasa.gov]

With video:

Alien spaceship exhaust ?

I like to post here with the Rosetta news most days even if it's just a quick NAVCAM shot. Recently I have had a lot of problems staying on GLP, I don't know what is causing it ( as usual ) but if you don't see any Rosetta posts from me for a few days you will know what has happened. So with that in mind I just want to say the next six month's will be one of the most fantastic periods ever in space exploration.

From next month we will start to see amazing pictures of Ceres from the Dawn spacecraft. By the end of the month we may have heard from the Philae lander, although that is taking an optimistic estimate. Philae will probably have woken by the end of May. New Horizons passes Pluto in mid July giving us our first real look at the dwarf planet. Mid August marks perihelion for comet 67P. Rosetta and Dawn will be busy throughout the year now. Let's not forget we have MSL, Cassini, HST and others still producing great discoveries.

K

Time flies! Eleven years ago today Rosetta launched into space on its ten year journey to Comet 67P/C-G.

Read the original news story announcing the launch:

2 March 2004

ESA PR 14-2004. Europe’s Rosetta cometary probe has been successfully launched into an orbit around the Sun, which will allow it to reach the comet 67P/Churyumov-Gerasimenko in 2014 after three flybys of the Earth and one of Mars. During this 10-year journey, the probe will pass close to at least one asteroid.

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[link to www.esa.int]

I remember watching this launch!

cthulhu's boner piercing the veil.

Miss Rosetta, we're ready for your close up now

OSIRIS image 11cm/pixel from 6km 14th February
[link to www.esa.int]

There you go, Holger Sierks has been temporarily restrained and we have the promised image of Rosetta's shadow passing over the surface of the Imhoptep region during the close fly -by :)

read all about it here
[link to blogs.esa.int]

K

How cool is this? Rosetta Mission sees its own shadow while making a low pass over the comet!!

Does this count as a selfie?! Rosetta's OSIRIS camera captured the spacecraft's own shadow on the surface of Comet 67P/C-G during its recent close flyby. The image here is 228 x 228 m and the shadow is approximately 20 x 50 m.

Comet flyby: OSIRIS catches glimpse of Rosetta’s shadow

Images from the OSIRIS scientific imaging camera taken during the close flyby on 14 February have now been downlinked to Earth, revealing the surface of Comet 67P/C-G in unprecedented detail, and including the shadow of the spacecraft encircled in a wreath of light.

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full article with superduper pictures here:
[link to blogs.esa.int]