I Dawn dead in Ceres orbit, ran out of fuel Oct 2018

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    Fuel Orbit
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The Dawn spacecraft successfully observed Ceres from a distance of 238,000 miles on January 13, 2015, capturing over half of its surface at a resolution of 27 pixels. The mission aimed to enter a polar orbit around Ceres, with a planned descent to an altitude of 375 km, but faced challenges due to limited hydrazine propellant for attitude control. A cosmic ray event in September 2014 had previously disrupted the propulsion system, complicating the approach trajectory. Despite these issues, the spacecraft was expected to achieve a stable orbit around Ceres, ultimately becoming a "perpetual satellite" as it ran out of fuel. The mission's success would provide valuable data on Ceres' physical characteristics and surface mapping.
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Astronomy news on Phys.org
  • #872
==Rayman==
March 18 - Dawn Concluding Another Week of Observations

After spending most of the week observing Ceres, Dawn paused this morning to point its main antenna at Earth. It is now radioing its precious data to the Deep Space Network. It will resume its measurements tomorrow around noon.
==endquote==
 
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  • #874
The 47th Lunar and Planetary Science Conference is apparently underway. The Woodlands, Texas, March 21–25, 2016.

Tons of stuff being tweeted about Ceres. Even a picture of Occator's main bright spot!
Apparently JPL will be releasing images tomorrow.
But in the meanwhile. And don't tell anyone I did this:

Occator.center.bright.spot.LPSC2016.03.21.jpg

source: https://twitter.com/Laurent_Montesi

There's an interesting whiteboard drawing on this guys page: https://twitter.com/jtuttlekeane
Look for the name: Anton Ermakov
Anton Ermakov- Occator is associated with a negative Bouguer anomaly; low density intrusion? ​

And what the heck?
Kimberly EnnicoSmith ‏@kennicosmith 14 hours ago
Castillo: #Ceres showing evidence for a lack of ice shell (not expected). The surface is rocky with a thick rock layer. #LPSC2016​

No ice shell?

[edit]
I forgot to mention:

Keri Bean ‏@PlanetaryKeri 1 hour ago
Keri Bean Retweeted NASA's Dawn Mission
Seriously though tune in for the press briefing tomorrow. I guarantee you won't regret it. #SCIENCE​

Keri Bean added,

CeF7ZtkUEAAvKpS.jpg

NASA's Dawn Mission @NASA_Dawn
Exciting news tomorrow! For now: a pretty standard #Ceres scene http://go.nasa.gov/1pXzQzd
 
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  • #875
Capture.PNG


I'm particularly pleased with the profile view of the "mons"
 
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  • #876
A great picture of the bright spot.
It looks almost fractal - no matter how good the images get, there are always finer details where you would want to zoom in.
 
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  • #877
mfb said:
A great picture of the bright spot.
It looks almost fractal - no matter how good the images get, there are always finer details where you would want to zoom in.
If you look closely at the bottom of the image, you'll see the top of a couple of people's heads.
So that was a cell phone capture from a presentation.
I would imagine the "official" photo will be a bit clearer.

And this just in:

NASA's Dawn Mission ‏@NASA_Dawn 18 minutes ago
Press briefing about #Ceres will be at 12p CT/1p ET at #LPSC2016. Tune in for new images/materials then. ​

hmmmm... Where do we tune in?
(google, google, google)
Here maybe? http://livestream.com/viewnow/LPSC2016
 
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  • #878
Patiently awaiting more imagery. :thumbup:
 
  • #879
1oldman2 said:
Patiently awaiting more imagery.

Sorry for my delayed response. :oldwink:

Dawn/JPL just released 6 new images!
Here's a screen capture of Occator's central bright spot.

zoom.of.PIA20355.Occator.bright.central.spot.from.LAMO.released.2016.03.22.jpg


Woo Hoo!

ps. Lot's of interesting chatter going on at #LPSC2016.
 
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  • #880
OmCheeto said:
Woo Hoo!
:smile: This just keeps getting better! Thanks for sharing this.
 
  • #881
  • #883
Stephen Clark ‏@StephenClark1 41 minutes ago
Carol Raymond, Dawn: If the spacecraft ’s reaction wheels continue working, mission at Ceres could last till this time next year. #LPSC2016​

:partytime:

Emily Lakdawalla ‏@elakdawalla 1 hour ago
Dawn at Ceres press briefing beginning now. It's not being webcast but is being recorded for later streaming. #LPSC2016​

Thank god. I thought I was losing my touch, and/or mind.

James Tuttle Keane ‏@jtuttlekeane 1 hour ago
Mickey Villarreal- Spurious electrons betray a bow shock at Ceres; either from atmo or conductive layer #LPSC2016
CeKsOPiUEAAEkzI.jpg

James has some really cool doodles.
 
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  • #884
OmCheeto said:
Good grief! Why did they have to release everything at once. This is going to take me weeks to sift through! :oldsurprised:
I'm officially overwhelmed, but my "links folder" is filled with enough sites and info to keep me busy for a very long time. Good show! :thumbup:
As a young kid I remember looking at "artists impressions" of Ceres and thinking of how cool a place it was, This is in another league altogether.
 
  • #885
1oldman2 said:
I'm officially overwhelmed, but my "links folder" is filled with enough sites and info to keep me busy for a very long time. Good show! :thumbup:
As a young kid I remember looking at "artists impressions" of Ceres and thinking of how cool a place it was, This is in another league altogether.

I'm still trying to figure out what a "Bouger Anomaly" is.
I was going to make a lame joke, and misspell it as "Booger Anomaly", pointing out that "If it's boogered, of course it's an anomaly...", but I'm sure people are tired of my jokes by now. :redface:

ps. I see from your profile, that you're my age. I don't even remember hearing about Ceres when I was a kid. And 40 years ago, Ceres would have just been a point image. hmmmm... (google, google, google)
Holy Cow!
Those are really impressive.

Seeing Ceres: Then and Now
Posted by Paul Gilster
2015/03/06 15:33 UTC
1980.vs.2016.images.of.Ceres.and.Vesta.tumblr_nktdkjPbzM1rdy7odo1_1280.jpg
 
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  • #886
I'm still trying to figure out what a "Bouger Anomaly" is.
I was going to make a lame joke, and misspell it as "Booger Anomaly", pointing out that "If it's boogered, of course it's an anomaly...", but I'm sure people are tired of my jokes by now. :redface:

Naw, the booger joke is a natural. You would have been forgiven. As a young kid I was hooked on Space flight from the days of Mercury etc. Always wondered how those rocket ships could do a controlled vertical landing in the "Twilight Zone" episodes. Then I realized that they can't, So now we have Falcon 9's doing what was impossible, Talk about perspective, eh?
 
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  • #887
I have to bring forward the image in Om's post #880, on preceding page
==quote==

Dawn/JPL just released 6 new images!
Here's a screen capture of Occator's central bright spot.

zoom.of.PIA20355.Occator.bright.central.spot.from.LAMO.released.2016.03.22.jpg


Woo Hoo!

==endquote==
 
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  • #888
That is an amazing image of Occator and the "bright material", have any conclusions been reached as to what the material is?
 
  • #889
Note that they changed colors and contrast in that image:
Center of Occator Crater (Enhanced Color)
The bright central spots near the center of Occator Crater are shown in enhanced color in this view from NASA's Dawn spacecraft . Such views can be used to highlight subtle color differences on Ceres
I think "something salt-like" won.
 
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  • #890
One commonly mentioned guess is hydrated magnesium sulfate. Somewhat akin to Epsom salts.

BTW one of the new images shows the variation of hydrogen abundance in the N hemisphere regolith (loose surface material in the top 1 meter.)
http://dawn.jpl.nasa.gov/multimedia/images/image-detail.html?id=PIA20353

bluer signifies fewer neutrons and thus more hydrogen---hydrogen presumably in the form of water, in the soil, slows neutrons when they collide with it---fewer escape to be detected by the fast neutron counter in the GRaND instrument (gamma ray and neutron detector)

So what the image shows is not too surprising: more hydrogen (hydrated minerals, water ice,...etc) in the surface layer around the N pole. less hydrogen in lower latitudes closer to the equator.
 
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  • #891
mfb said:
Note that they changed colors and contrast in that image:
I think "something salt-like" won.
I hadn't noticed the color/contrast change until you mentioned it, at the present I'm too busy looking at the forest to see the trees. lots of great images, this is going to keep me occupied for a while.
Salt of one type or another is the explanation I have heard, but I'm thinking that Ceres has a lot of surprises in store so I thought I'd ask. Thanks for the feedback. :smile:
 
  • #892
marcus said:
BTW one of the new images shows the variation of hydrogen abundance in the N hemisphere regolith (loose surface material in the top 1 meter.)
http://dawn.jpl.nasa.gov/multimedia/images/image-detail.html?id=PIA20353
An incredible variety of elements, I would think "asteroid mining" could become big business at some future point.
Not sure how I ended up with my reply in the quote but I guess it works anyway.:doh:
 
  • #893
1oldman2 said:
An incredible variety of elements, I would think "asteroid mining" could become big business at some future point.
I agree with your comment. Ceres is apt to be central to any attempt to use asteroid material for human purposes. For one thing, because in one form or another it has water (so we think) it has the makings for fuel.

It might become the center of a chemicals industry, and or a construction materials industry, probably located below the surface. Manufacturing in low gravity has advantages.
 
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  • #894
They did eventually get the video online from the meeting this morning:

Press Briefing: Ceres: Dispatches from a Dwarf Planet

For some reason, the sound doesn't work if I play it at the lowest resolution: 272p.
But it does work at the other resolutions: 432p, 480p, & 720p.
 
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  • #895
OmCheeto said:
They did eventually get the video online from the meeting this morning:

Press Briefing: Ceres: Dispatches from a Dwarf Planet

For some reason, the sound doesn't work if I play it at the lowest resolution: 272p.
But it does work at the other resolutions: 432p, 480p, & 720p.

Appreciate the link and info, can't wait to see what they have to say. :smile: (I see it's keeping you up late also)
 
  • #897
OmCheeto said:
They did eventually get the video online from the meeting this morning:

Press Briefing: Ceres: Dispatches from a Dwarf Planet

For some reason, the sound doesn't work if I play it at the lowest resolution: 272p.
But it does work at the other resolutions: 432p, 480p, & 720p.
Definitely worth watching! The GRaND segment starts around minute 19:28. The questions from press start around minute 30:00 and they are good--they elicit interesting answers which are often more speculative and more deeply informative than the initial presentations. I wouldn't skip the Q&A.

1oldman2 said:
Interesting reading in this take on things.
http://www.bbc.com/news/science-environment-31754585
That BBC article from Dec 2015 is also informative. Different albedo figures for different parts of the Occator bright spots, and so on. Thanks for posting it!

Here's something more recent about that:
http://news.discovery.com/space/is-ceres-mysterious-bright-dome-an-ice-volcano-160323.htm
It derives from yesterday's (Tuesday's) press conference that we can watch in full via Om's link.
 
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  • #898
==Rayman==

March 22 - Dawn Revealing New Sights

Dawn is healthy and continuing its observations of Ceres. After transmitting data to Earth on March 18 and 19, the spacecraft began a new set of measurements. Now, instead of looking straight down, it is pointing its sensors a little bit to the left as it circles Ceres. This provides a slightly different perspective on the alien landscape and may reduce the rate at which the probe consumes its dwindling hydrazine propellant. (Hydrazine is essential for Dawn's operation.)

A new view of the famous bright area in Occator crater, photographed by Dawn from the closest it will ever come to the intriguing geological feature, is now available here.You can see other new Ceres images based on Dawn's measurements at the Ceres image gallery
==endquote==
PIA20350_fig1.jpg


The brighter (parts) of the bright spots could be water ice and newer. the not so bright spots could be older---salt residue after the water ice sublimes
 
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  • #899
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  • #900
marcus said:
Here's an article that features that same (colored) image that Om posted:
http://techcrunch.com/2016/03/23/ceres-mysterious-bright-spots-revealed-in-unprecedented-detail/
It was processed some (the color data came from an earlier orbit and was superimposed). Mfb referred to this. So I thought it would be good to have the straight black and white version as well.
Interesting article, thank you for linking that. I've been busy sorting through all the image downloads that have come up lately here, lots to look at. Some of the imaging when zoomed in on is still amazingly detailed and my curiosity is killing me on certain features, can't wait to hear explanations for some of what we are seeing. :thumbup:
 

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