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Dawn: New Imagery of Ceres

Mark January 26 on your calendar. It’s the day when the Dawn spacecraft will take images of Ceres that should exceed the resolution of the Hubble Space Telescope. We’re moving into that new world discovery phase that is so reminiscent of the Voyager images, which kept re-writing our textbooks on the outer Solar System. 2015 will be a good year for such, with Dawn being captured by Ceres gravity on March 6, and New Horizons slated for a July flyby of Pluto/Charon. In both cases, we will be seeing surfaces features never before observed.


What we have so far from Dawn can’t match earlier Hubble imagery, the best of which is about ten years old, but it’s about three times better than the calibration images taken by the spacecraft in early December. At this point, Dawn is making a series of images to be used for navigation purposes during the approach to the dwarf planet. We have sixteen months of close study of Ceres to look forward to as the excitement builds. “Already,” says Andreas Nathues, lead investigator for the framing camera team at the Max Planck Institute for Solar System Research, Gottingen, “the [latest] images hint at first surface structures such as craters.”

Image: An animated GIF showing bright and dark features on Ceres. The Dawn spacecraft observed Ceres for an hour on Jan. 13, 2015, from a distance of 383,000 kilometers. A little more than half of its surface was observed at a resolution of 27 pixels. Credit: NASA/JPL.

No spacecraft has ever visited a dwarf planet, another first for Dawn, which will also become the first spacecraft to have orbited two deep space destinations following its 2011-2012 sojourn at Vesta, where it produced over 30,000 images. Jian-Yang Li (Planetary Science Institute), who led the Hubble mapping of Ceres, says that even the early observations will be significant:

“Reproducing the Hubble observations is important to understanding the nature of Ceres’ surface. The recent detection of episodic water vapor near Ceres’ surface by the Herschel Space Observatory at a longitude observed by Dawn might arise from activity that could change Ceres’ surface over time.”

That discovery, relying on data taken in 2012, took advantage of the HIFI instrument on Herschel, which showed water vapor being emitted from the surface of Ceres, an early indication that Ceres has an icy surface and an atmosphere. Variations in the water signal during the dwarf planet’s nine hour rotation period helped Herschel scientists trace the water vapor to two spots on the surface. The two emitting regions are about five percent darker than the rest of Ceres, likely warmer regions that provide efficient sublimation of small reservoirs of water ice. In very short order, thanks to the Dawn spacecraft, we will be able to observe such features in dazzling detail.

For more on the Herschel work, see Küppers et al., “Localized sources of water vapour on the dwarf planet (1) Ceres,” Nature 505 (23 January 2014), 525–527 (abstract).


Comments on this entry are closed.

  • Tulse January 20, 2015, 12:38

    I’ve seen mention that Ceres may have substantial subsurface water. Will Dawn be able to determine if there is indeed an ocean under the surface of Ceres?

  • RobFlores January 20, 2015, 12:40

    I believe most models show Ceres as having a relatively shallow ocean
    and larger Rocky Core, compared to the Jovian Moons. If Ceres turns
    out to have a rather thin ice crust, I would assume that many modest sized
    asteroid strikes (25m-100m) penetrate and deposit debris on to the assumed ocean.
    If somehow microbial life arose there, It’s probably in the pores
    of the rocky core. Ceres is pretty small, so a much larger strike in the
    1km range is probably capable of sterilizing the ocean, (unless of course
    it’s part of some microbes life cycle…).
    Ran some numbers, and any visitors there will certainly be able to
    bound 30m at a time, (Straight up I believe one could leap up to 70m,
    more if you are a top athelete.)

  • Michael January 20, 2015, 15:08


    ‘If somehow microbial life arose there, It’s probably in the pores
    of the rocky core. Ceres is pretty small, so a much larger strike in the
    1km range is probably capable of sterilizing the ocean, (unless of course
    it’s part of some microbes life cycle…).’

    The core of Ceres is expected to be cracked due to thermal stresses if it is differentially layered and the pressure down there is bearable for life. As for the larger asteroid strikes it is unlikely to sterilise the whole ocean. Most of the impactor and a larger amount of Ceres will be blown back into space because of the low gravity leaving most of the ocean intact but oscillating which may aid life underneath the ice by allowing materials to rain down into the ocean below through the cracked ice.

  • galacsi January 20, 2015, 16:04

    So exciting ! I cannot wait for these new detailed photos !
    And what can explain these hot spots ? Impact ? Cryovolanisme ?
    Could Ceres have a magnetic field ?
    Wow I must stop and calm down !

  • ljk January 20, 2015, 18:03

    Phil Plait’s take on these new Ceres images from his Bad Astronomy blog:


  • Wojciech J January 20, 2015, 18:49

    It’s humbling to realize that for the discussions about life, Fermi Paradox, we haven’t even seen, or even explored most of our Solar System.

    Ceres is a fascinating subject and I am thrilled to be able to see a new world for the first time(imagine what people felt when Voyager was taking first photos).

    Let’s hope we learn as much as we can-IIRC unfortunately Dawn has little capability to detect water.

  • Lionel January 20, 2015, 18:50

    Those five hundred odd pixels and thirty degrees of spin gave me shivers! Man I’m excited

    And images of Pluto and Charon are coming too… What a wonderful year this will be

  • ljk January 20, 2015, 22:52

    Zachary V. Whitten. Use of Ceres in the Development of the Solar System – PDF (16.4 KB):


  • Michael January 21, 2015, 6:23

    From the looks of it, it is an ice ball with a dusty cover as it looks like there is an impact crater exposing sub-surface ice in the video. The surface also looks like it has a lot of craters which would favour an undifferentiated body and little hope for sub-surface ocean.


  • Michael Spencer January 21, 2015, 7:59

    What a great time to be alive!

  • Lionel January 21, 2015, 8:46

    Somewhat off topic but wondering whether anyone here has done a virtual reality tour of the solar system with Titans of Space on Oculus Rift?

    Looks absolutely fantastic and I’m so keen to give it a go. For anyone who hasn’t seen a video I’d recommend taking a took on YouTube – there’s lots of videos – to see what it’s about. Looks to me like this VR technology is already making an impact in engaging the public with space

    (and btw, yes, Ceres is in there too :) )

  • Rob Henry January 21, 2015, 15:37

    @galacsi don’t just get excited, model the most extreme situation that you can explain in detail and can defend (such as that magnetic field). If you are wrong, everyone will forget you made it in a couple of months in the excitement of the new data, but if you are right…

    @RobFlores, the world high jump record is by Javier Sotomayor who Fosbury flopped his 1.3m high centre of mass about 10cm below a bar of 2.45m height for a gain of 1.05m. Now, IF he could sustain the same ground contact forces when his limbs were moving half a dozen times their natural speed, on Ceres he could make a bar of 1.05 x 36 + 1.4 = 39.4m. In reality it would be less, perhaps close to that 30m, but, for normal humans, that looks a bit optimistic IMHO.

  • Ron S January 21, 2015, 17:56

    Rob: “…world high jump record…”

    Do a pole vault as a more highly efficient redirection of momentum.

  • ljk January 21, 2015, 18:01

    Dawn’s Greatest Glimpse Yet of Ceres Hints at Startling Revelations Soon to Come

    By Ken Kremer

    We’ve wondered about Ceres‘ nature and true identity for over two centuries, ever since it was discovered on New Year’s Day, 1801, by Giuseppe Piazzi of Italy. It’s been alternately classified as a planet, asteroid, and more recently as a dwarf planet.

    Just gander in amazement at the greatest glimpse yet of the infant world and you’ll quickly realize we are now clearly on the cusp of startling new revelations about the mysteries of Ceres.

    And it’s all thanks to NASA’s ion-powered Dawn spacecraft and its revolutionary ion propulsion system now zeroing in on its final approach phase to Ceres for humanity’s first up-close look at the pristine protoplanet.

    Today NASA released the most fantastic images yet of the dwarf planet Ceres that were taken just days ago, on Jan. 13, 2014, from a distance of 238,000 miles (383,000 kilometers). That’s about equivalent to the distance from the Earth to the Moon.

    The new photos clearly reveal tantalizing hints of craters, ridges, and a rather varied topography with a wide assortment of especially intriguing bright and numerous dark splotches, which we can only guess as to what their true nature and composition may be. Does frozen or liquid water and possibly an alien ecosystem lurk beneath?

    Full article here:


  • Alex Tolley January 21, 2015, 18:59

    Xkcd’s take on that white spot: http://xkcd.com/1476/

    I expect the real structure will be fascinating – a relatively recent crater exposing subsurface ice?

  • Rob Henry January 22, 2015, 1:35

    @Ron S, the best sprinters can attain 11m/s at peak, but those carrying a pole would be slower. Our record is 6.16m by a much shorter man than the high jump, so the COM rise is close to 5m, which equates to a take off speed of 10m/s. Now on Ceres, it is debatable if the lower gravity (and so lower track friction) would produce higher or lower sprint speeds, but the much longer pole caried would be a killer. I’m thinking only 9m/s. Ceres gravity is .27m/s/s So that gives us…
    (9^2 / 2 / .27) + 1.16 = 151m.

  • Ron S January 22, 2015, 20:57

    Yes, I had considered that sprinting is a problem, but one that applies equally to both athletes. Running technique will obviously be a bit…unique…though one that will require a longer runway for both events. I also suspect the pole vaulter’s top speed may be closer to that of the jumper than you suggest because the lower frequency of ground contact in a low-g run would permit more efficient acceleration and balancing of the lower-weight pole than on Earth.

    At the 2104 Olympics on Ceres we’ll know for sure.

  • ljk January 23, 2015, 13:15
  • Rob Henry January 24, 2015, 0:36

    @Ron S, after you comments I realised that I made a rather subtle error in my high jump figure by flipping between two models. Here I recalculate and stick to one.

    In a high jump there will be a small gain by converting horizontal energy into vertical gain – lets ignore it. We model high jumping as a jump straight from a crouch, so, if I assume “he could sustain the same ground contact forces when his limbs were moving half a dozen times their natural speed”, then we must also assume the acceleration phase produces more usable ‘thrust’. Another way to look at it is, a very unfit man, just able to lift his own body from a crouch has his feet pushing down on Earth hard enough to accelerate his COM at 10m/s/s. To cut a long explanation short, I left out a factor, f that would make sense of the above self quote.

    The high jump record on Ceres would NOT be
    1.05 x 36 + 1.4 = 39.2m
    but rather
    1.05 x 36 x f + 1.4
    now, if y is the Earth record height, and x is the crouch – release acceleration phase lift distance of the COM, then, ignoring Ceres gravity as insignificant and assuming that acceleration is applied linearly, I make
    f = (x+y)/y
    this should be somewhere from 1.2 to 1.8. I’m guessing 1.5.

    So it seems that 30m on Ceres is likely for the reasonably fit, and 60m might be possible for Javier Sotomayor after all. Only air friction might be a problem – but on Ceres air is as rarefied as the athletes want.

  • ljk January 27, 2015, 13:01

    New images of Ceres from January 25, 2015 at a distance of 147,000 miles or 237,000 kilometers:


    JANUARY 26, 2015

    Asteroid That Flew Past Earth Has Moon

    This GIF shows asteroid 2004 BL86, which safely flew past Earth on Jan. 26, 2015. Image Credit: NASA/JPL-Caltech

    Scientists working with NASA’s 230-foot-wide (70-meter) Deep Space Network antenna at Goldstone, California, have released the first radar images of asteroid 2004 BL86. The images show the asteroid, which made its closest approach on Jan. 26, 2015 at 8:19 a.m. PST (11:19 a.m. EST) at a distance of about 745,000 miles (1.2 million kilometers, or 3.1 times the distance from Earth to the moon), has its own small moon.

    The 20 individual images used in the movie were generated from data collected at Goldstone on Jan. 26, 2015. They show the primary body is approximately 1,100 feet (325 meters) across and has a small moon approximately 230 feet (70 meters) across. In the near-Earth population, about 16 percent of asteroids that are about 655 feet (200 meters) or larger are a binary (the primary asteroid with a smaller asteroid moon orbiting it) or even triple systems (two moons). The resolution on the radar images is 13 feet (4 meters) per pixel.

    The trajectory of asteroid 2004 BL86 is well understood. Monday’s flyby was the closest approach the asteroid will make to Earth for at least the next two centuries. It is also the closest a known asteroid this size will come to Earth until asteroid 1999 AN10 flies past our planet in 2027.

    Asteroid 2004 BL86 was discovered on Jan. 30, 2004, by the Lincoln Near-Earth Asteroid Research (LINEAR) survey in White Sands, New Mexico.

    Full article here: