Dawn is now officially in orbit around (1) Ceres!

Congratulations, NASA. Nice images of crescent Ceres.

NASA Spacecraft Becomes First to Orbit a Dwarf Planet

I thought it was time for a new thread, now that Dawn's in its first orbit. We can look forward to a couple more op navs, on April 10 and 14, and then RC3 later in the month. Use the previous thread for up to Op Nav 5; let's use this thread for Op Navs 6 and 7 and RC3 and then we'll split again once Dawn reaches its first survey orbit.

thanks emily!

i noticed in a prior thread that it said mapping starts in July. thats a bit of a misnomer as mapping starts in Survey Orbit in May (and one can count RC3 as a global map, at about 1.5 km resolution, which is comparable to much of Voyager at Saturn.) wows!

What should nonetheless be correct is that a new mapping phase starts in July, namely HAMO; and that this is still the month New Horizon zooms past Pluto.

Also the time when the fireworks on 67P are expected to really start.

From http://www.nasa.gov/press/2015/march/nasa-...ly-enter-orbit/ :



Does anyone know if a recording of this telecon exists? Normally, at the end of a NASA telecon they offer a number that you can call into to hear it again -- inexplicably, they only offer that number DURING the call itself. Also, JPL will sometimes take the audio and make a video out of it (synced with slides if there are any) and upload to the Ustream or Youtube account.

Or was there absolutely nothing of interest said during the telecon, just the usual recapping of what's happened?

Thanks!

Link to the recorded "Dawn Ceres Arrival" briefing.

Thanks but that's the PREVIEW briefing, that aired on NASA TV on Monday. I'm talking about the teleconference (media phone call) from Friday.

Searched for it on YouTube:

https://www.youtube.com/watch?v=Qk0Cr0Z13hc

Edit: finally had a chance to listen to it - nothing new was said, really.

And Voyager 2 might break out into interstellar space at about the same time also. The values for the interstellar >70 MeV protons have been slowly climbing to the same value as for V2 - though if the current trend holds it might happen a few months later.

THANK YOU!!!

It must be an unusual sight. The narrow sickle of Ceres with constellation of Orion in background.
Click to view attachment

Thanks Peter,
just dipped outside for a look and there is Orion, laying in the west. Go Dawn.

Thanks. That certainly puts things into perspective.

Oh my, talk about making the familiar unusual....

I like these perspective jolting moments. My absolute favorite is earth and the moon seen from mercury during the lunar eclipse.

Dawn is currently communicating with Earth. Here's hoping for some of spot(s) 5.

http://eyes.nasa.gov/dsn/dsn.html

for those interested this is the orbit for the Dawn spacecraft as in spirals down to a lower orbit over the next few weeks



the red line is the spacecraft orbit
generated from the
dawn_ql_150219-150531_150415_v1.bsp
dawn_ref_150423-150704_150414_DA400_v1.bsp

naif kernels

Dawn Glimpses Ceres' North Pole
http://dawn.jpl.nasa.gov/news/Dawn_glimpse..._north_pole.asp

JPL has released an animation of the April 10 opnavs. Very cool



On Twitter, Brian Wolven asked me if the prominent bright peaks seen at the right-hand limb at the beginning of the animation were the two bright spots. I tried to figure out the answer to that, but couldn't. I made the attached polar projection of the northern hemisphere of the DEM from JohnVV's map, but I couldn't match crater features.

it would NOT be visible YET in the April 10 images

it is at 20 deg North
what is visible in that gif is 50+ to 90 north
as you can see in these two screenshots ( if the naif kernels are accurate, i have been having MAJOR issues with some of them )
added extra light to the scene
-- FOR APRIL 10 like the gif--
near the center

- off to the right side of ceres

Pleasantly surprised to see that OpNav 6 was released today. Something odd happens when I try to extract the individual frames with IrfanView, though: the frames come out in all sorts of sizes. (edit: never mind, Python to the rescue)

In the latest Dawn Journal, it was mentioned that spot(s) 5 would not be visible in OpNav 6:



so I think it would be odd if they suddenly turned up anyway.

Thanks for those simulations, they are really helpful.

in the northpole image you posted the two side by side bright spots are the line here circled


and it will be visible TODAY but not much better than before. just from a different angle

I think this mound (or mounds) in the large crater is a good candidate for the limb peaks:

Click to view attachment

Note the trio of craters circled in red:

Click to view attachment

They seem to correspond with the craters in red here:

Click to view attachment

Now extend a longitudinal line over the north pole here:

Click to view attachment

And here (north pole marked with 'N'):

Click to view attachment

The peaks are to the east of the line. The crater with the mound(s) is marked with a yellow box on the longitudinal map.

With the following assumed globes for PIA19317.gif OpNav6

I've obtained these projections:

Addition of the projections to the DLR map from RC2:


The bright spot is probably just outside frame 20 of the sequence.

aligning the animated gif with the textured mesh and lat long marks

the other "bright spot" is at 42 N and 0 long.
it is barely visible in the gif
3 frames from the gif with and without a spherical grid
the 0/360 long is top right on the sphere and you can see the major bright spot

hidden under the horizon

almost visible on the top left

Ceres rotating back and forth in latest images from Dawn spacecraft.
I find it much easier to spot different surface details this way.

Click to view attachment

Thank you for your effort Toma. Now this make me think the surface resemble a golf ball. =)

I can't figure out if bright spot is visible in the animation.
I place here the other available images for more comfortable comparisons:
http://cdn.phys.org/newman/csz/news/800/20...warfplanetc.jpg
http://cdn.phys.org/newman/csz/news/800/20...hisimageist.jpg
https://lightsinthedark.files.wordpress.com...3/pia189231.jpg
http://www.jpl.nasa.gov/spaceimages/images...19056_hires.jpg


I don't understand if I must link them or upload them or insert them in tag so I just add the links.

It isn't.

Im rather curious about these two spots that appear in frame 6 and frame 7. Not necessarily from spot 5 but in the same vicinity. They are somewhat dim and on the left lim.
Click to view attachment

ZLD - your map is upside down

That is the two side by side spots that are at 20 degrees NORTH and 240 degrees longitude and is visible in the added light 3d graphic I posted here of the two recreations that show where it WOULD be IF it was lite

http://www.unmannedspaceflight.com/index.p...st&p=219593


you can see in the first image ( added extra AMBIENT light ) to the 3d rendering

JohnVV, thanks much for the simulations with the grids. They really help to put things into perspective.

Also, have you yet added the grid to the global cylindrical map?

the grid is dynamically added in the 3d program i am using .

Ceres's orbit is calculated using the JPL orbit data and Dawn's orbit is also calculated using it's orbital data the same data that the research scientists are using the naif kernels.

As to the map. The map posted is 0 long to 360 long ( 180 in the center ) a grid could be added ? but not really needed this very EARLY map is very low resolution 1024x512 pixels and the poles ARE MISSING.

In comparison the published Vesta map is 48 ppd ( 17,280 X 8,641 ) pixels .

Is the dimmest bright spot resolved in the OpNav 7 images? It looks distinctly elongated in all frames where it "glows":

The accompanying press release text clearly states

"The images show the brightest spot and its companion clearly standing out against their darker surroundings......"

I don't see how that implies that they are resolved.

Are you asking if the impression that the elongated spot is split up into three parts can be trusted? Looks like it to me, but you know what my opinion's worth!

Just noting that it looks like it spans more than one pixel at this resolution (and also that it looks elongated from this vantage point). Looking a bit more closely at the images, it seems almost certain to me that it is resolved; but I haven't seen any relevant comments from the science team.

from the tiny gif that is PIA19064

it is looking like the one bright spot at 0 long.( 360 long.) and 42 North

is in fact ejecta from a crater ( i am GUESSING that the OTHER side by side bright spot at 240long and 20 North are ALSO ejecta)

4x enlargements from the 8 bit INDEXED gif
Click to view attachment Click to view attachment Click to view attachment Click to view attachment

The surface between the craters looks very smooth. The smooth areas between craters may only appear that way because of smaller craters can't be seen due to the low resolution of the current set of images. But, so far, there does not appear to be mountains or ridges between the craters.

Also, when I imagine a generic crater, say on the moon, I think of the surrounding of it sloping up fairly steeply then the surface dropping sharply as you go into the crater. But I don't see much of a rise on the outside edges of the craters. Are these craters really that smooth or does it look like that because the resolution or sun angle in these images? If they are really that slightly sloped on the outside, could it be because of what might be below the surface or

do to the fact that Ceres is very high in ices the craters have flat bottoms and are shallow

the one in the crops i posted looks to be on one of the ridges and came in at a very shallow angle

some of the "smoothness "is do to the 4x enlargement and that the original crop was only 128 px on a side ( rather small)

keep in mind that the spacecraft is NOT YET even in a near circular orbit YET
and this set of images is from April 14/15 -- LAST WEEK

Yes I tend to agree thinking its resolved or nearly so on the first image of the sequence, but on the subsequent images it seem to get saturated and float into adjacent pixel areas -and so larger than it actually is -again


Edit: It's not the first, but frames 8 and 9, the page loaded to slow so I missed the early part of the rotation sequence, but I did separate the images after the post to find out.

Back and forth animation made using grabbed frames from 20 frame gif.

All 20 frames separated into .png images on Dropbox.

The linear arrangement almost has the look of the "Voyager Mountains" on Iapetus...

Performed some slight enhancements on frame 10 of the PIA19064 animation. Cropped, luminance adjustment, deconvolution and scaled 200%.
Click to view attachment

And again with frame 11.
Click to view attachment

These are stretched until the bright region is slightly below max saturation.

The bright spot seems to be less prominent when on the morning terminator than on the evening. One possibility is that much of the bright material is on a west-facing slope.

Dr. Chris Russell, principal investigator of the Dawn mission, indicated in an e mail today to NBC News that even at the current resolution (1300 2100 meters/pixel) the bright spots were not resolved. This will presumably necessitate a marked revision upward of the albedo of the spots, which was set a minimum of 40 percent, based on the previous resolution of 3.7 kilometers/pixel.
NBC News Article

The fact that these things were visible from Earth still blows my mind. How small would they have to be before we get in the range of an Enceladean albedo?