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Sharper Views of Ceres

The mapping of Ceres continues at a brisk pace. The Dawn spacecraft is now operating at 1470 kilometers from the surface, taking eleven days to capture and return images of the entire surface. As this JPL news release points out, each eleven day cycle consists of fourteen orbits, so we’re accumulating views of this formerly faint speck in unprecedented detail. Within the next two months, Dawn will map Ceres — all of Ceres — six times.

Have a look, for example, at this view of one of Ceres’ more intriguing surface features. Taken by Dawn’s framing camera on August 19, the image has a resolution of 140 meters per pixel.

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Image: NASA’s Dawn spacecraft spotted this tall, conical mountain on Ceres from a distance of 1,470 kilometers. The mountain, located in the southern hemisphere, stands 6 kilometers high. Its perimeter is sharply defined, with almost no accumulated debris at the base of the brightly streaked slope. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.

The naming of surface features also continues, the image below showing a mountain ridge at lower left that’s in the center of Urvara crater. The 163-kilometer Urvara takes its name from an Indian and Iranian deity of plants and fields.

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And below we have Gaue crater at the bottom of the frame, named after a Germanic goddess of the harvest.

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JPL’s Marc Rayman, chief engineer for Dawn and mission director, notes the continuing success of the mapping operation:

“Dawn is performing flawlessly in this new orbit as it conducts its ambitious exploration. The spacecraft’s view is now three times as sharp as in its previous mapping orbit, revealing exciting new details of this intriguing dwarf planet.”

How to get views as good as Dawn is currently sending without actually making the trip? Rayman points out in his latest Dawn Journal entry that a telescope 217 times the diameter of Hubble could provide the same images, which makes a click on the Ceres image gallery all the more preferable. At its current height, Dawn’s camera sees a square 140 kilometers to the side, which is less than one percent of the almost 2.8 million square kilometer surface of the world.

Ahead for Dawn is a set of six mapping cycles (the images above come from the first of these), with changes in camera angle providing stereo views that will help us understand the topography. As it records infrared and visible spectra of the terrain, Dawn is also returning a radio signal that will help researchers probe the dwarf planet’s gravitational field, a key to the distribution of mass inside the object. At 308 million kilometers from Earth, Dawn’s radio signals take 34 minutes to make the round trip. Remember that all this is being accomplished despite the earlier failure of two of the craft’s reaction wheels, a problem in spacecraft orientation that has been surmounted by ground controllers and will not affect the outcome of the mission.

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Comments on this entry are closed.

  • Alex Tolley August 26, 2015, 11:42

    That bright scarped mountain is encouraging as it seems to indicate that it is formed of ice. If so, this might well explain those bright spots as ice too. What I am hoping for is some indication of whether Ceres interior is a frozen snowball, or contains a subsurface ocean.

  • Hop David August 26, 2015, 12:01

    “Dawn is also returning a radio signal that will help researchers probe the dwarf planet’s gravitational field, a key to the distribution of mass inside the object.”

    I’ve heard speculation that Ceres may have liquid water beneath her surface. I wonder if Dawn’s radio signals will shed light on this question.

  • W.E.B. August 26, 2015, 12:51

    I used to work in the arctic. That “mountain” sure looks like a pingo to me.

  • W.E.B. August 26, 2015, 15:29

    If it is a pingo, the weaker gravitational field of Ceres would permit a much taller structure than a terrestrial one. But pingos require a freeze /thaw cycle to grow, implying some interesting process below.

  • Michael August 27, 2015, 10:23

    Just thinking why the surface is not more relieved, is it possibly due to the constant rain of dust which coats the surface ice insulating it and thus keeping the surface very cold and stiff. As for these mountains could gases in the interior be responsible, say from clathrate decomposition?

    All that mineral rich dust and looks quite thick, WoW, a colonists dream.

  • J. Jason Wentworth August 28, 2015, 7:43

    ** GLOSSARY CHECK ** What is a pingo? I’ve never encountered that word before (and I’d wager that many readers here haven’t, either). It sounds interesting. Inferring from what you wrote, W.E.B., it -sounds- like something I observed (on a much smaller scale) in the red clay soil of northern Georgia, in the Blue Ridge Mountains. On days when the temperatures went above and below freezing, I frequently saw small (up to 3″ or so high, and ~1/4″ to ~1/2″ wide) quartz-looking columns of ice protruding upward from embankments along roadsides, and each ice column had a small rock or a clod of red soil on its top. Also:

    Looking at Dawn’s images of Ceres (and comparing them with the Vesta photographs), it’s amazing–and a little embarrassing–to think that we bypassed these interesting worlds for so long while sending probes to Jupiter and beyond! In Robert M. Powers’ fascinating (if a bit dated–if he’s still with us, I’d love to see him write an updated edition!) 1978/1979 book “Planetary Encounters,” the chapter on asteroids (which mentions that some might be extinct comets) has a NASA painting showing a hypothetical probe flying past three asteroids–one bright and spherical, one very dark and spherical, and one small, rather bright and irregular. The caption has stuck with me all these years (particularly its last line):

    “Solar electric spacecraft could tour the asteroid belt in a variety of missions in the late 1980s or early 1990s. Pioneer 10 was the first spacecraft to pass through the asteroid belt, proving that it was not necessarily dangerous. Asteroid belting has been humorously called ‘rummaging, so to speak, in the cosmic garbage.'” Now:

    Doing that has long fascinated me (solar sail or solar electric probes could range all over the main belt and poke around Jupiter’s trojan points). But given the surprises that Vesta and Ceres have presented to us, who knows what other totally unexpected things we will find at the other asteroids? In addition:

    One planetary scientist (I forget who she is–perhaps Reta [Rita?] Beebe?) is lobbying for a mission to the asteroid Psyche, which is a 140 mile-wide mass of solid metal. Is it magnetized? What kind of geological features does it have? What do craters on a metal world look like? Would any of them have central peaks, and how might any ejecta that fell back have piled up on the surface? These are just a few of the things (including information of possible commercial value) that we would learn from such a mission. The asteroids are mostly-neglected worlds (some of which are literally in Earth’s neighborhood) that are simultaneously fascinating, threatening (the PHAs), and economically promising.

  • ljk August 28, 2015, 9:06

    A mission to 16 Psyche would indeed be a fascinating and worthwhile mission, even lucrative some day. Here is an article on a proposed Discovery class probe to visit that planetoid:

    http://www.planetary.org/blogs/guest-blogs/van-kane/20140219-mission-to-a-metallic-world.html?referrer=https://www.google.com/

    Here is a brief overview paper on the Psyche mission plan:

    http://www.hou.usra.edu/meetings/lpsc2015/pdf/1632.pdf

    And should we not also explore a world shaped like an egg and just as smooth looking? I am talking about Saturn’s satellite Methone, which appears to be featureless perhaps due to a thick layer of dust. Why is this?

    http://www.planetary.org/blogs/emily-lakdawalla/2012/05211206.html?referrer=https://www.google.com/

  • Harry R Ray August 28, 2015, 9:40

    There are now hundreds of thousands of CATALOGED asteroids in the asteroid belt, and perhaps MILLIONS in existing (i.e. WISE, PANSTARS, Sloan, etc.) databases YET to be cataloged! Does ANY ONE OF THEM have an orbital period of PI(accurate to FIVE OR MORE DECIMAL POINTS)times Earth? Any such in existance now should be investigated FURTHER(first by an INTENSIVE groud based telescope examination, and then by SPACECRAFT) to determine whether it is INDEED an asteroid, or whether it, instead, may be anartificial structure! If any reader has the time and rescourses to scan the current list of asteroids, and then print out the asteroids whose orbital period ratios vis a vis Earth’s orbital period is EXYREMELY CLOSE TO PI, I would appreciate it!

  • Michael August 28, 2015, 11:29

    Just thinking what a rover on Ceres would see when looking at the mountain as there is bound to be layers which would have recorded the past conditions on this world. If there is/was life there it could be found in this exposed ice mountain.

  • Volucris August 28, 2015, 18:36

    I am intrigued by the Occator crater bright spots. I would think that such features would be fairly young, not being covered in dust. On the other hand the crater seems otherwise well covered in dust. But the brightest spot itself still sits in the very middle of the crater, suggesting that it’s occurrence is related to that of the crater. How, if they are of different age?

    If I’d be a sci-fi author, I’d place an alien probe right there, in the middle of the crated, under the ice. The bright blemishes would be signs of the formerly open cooling ponds from 1000 years ago, when the probe – now dormant – was last time flexing it’s fusion power plant in order to report back to it’s home world.

    Harry, I wonder with all the interactions between solar system planets an asteroid would keep ticking with earth to 5 decimal places even is somebody put it there like that (I doubt). But the idea gets me smiling, so, you could start combing right here:
    http://www.minorplanetcenter.net/db_search/show_by_properties?utf8=%E2%9C%93&period_min=3.14&period_max=3.15
    Even tho they give the periods to only 2 decimal places :)

  • J. Jason Wentworth August 29, 2015, 7:38

    That’s an interesting idea that Harry R Ray put forward; a Bracewell probe utilizing solar-powered, fuel-less propulsion (solar sail or Yarkovsky Effect propulsion) could maintain a solar orbit with a period of pi times Earth’s indefinitely. The natural log base e (2.718…[I forget the other few digits]) times Earth’s orbital period is another “attention-attracting” number that could be utilized by such a probe. Using such orbital periods would certainly be a zero-energy way (in terms of the probe’s *onboard* energy supply) to “broadcast” its presence. Also:

    SETA (Search for Extra-Terrestrial Artifacts) activities could and should be “piggybacked onto” the planetary science imaging and data collection at Vesta, Ceres, and the other asteroids. Such bodies–if our solar system was visited by interstellar explorers in the past–would have been attractive sources of volatiles, metals, and minerals (as well as deuterium, and possibly helium-3) to replenish their supplies of these materials during their stay(s). Such SETA-directed scrutiny need not be a problem for planetary scientists, as SETA researchers could study copies of the images and data reports at their own facilities. In addition:

    I don’t lose any sleep excitedly awaiting the announcement of artificial objects on Vesta or Ceres, but–as with SETI–if no one ever looks for such artifacts, we have zero chance of finding any if they are there. Besides, having extra eyes and minds examining the spacecraft findings will increase the likelihood that interesting small natural features on these worlds won’t escape notice.

  • Michael August 29, 2015, 9:22

    I am surprised at just how little pressure is needed to raise such a high 6km structure, it is around 14 bars which is not a lot, methane could provide this lifting force. To shear the ice will take a lot more but not that much as ice is weak in the shear direction.

  • J. Jason Wentworth August 29, 2015, 9:44

    ljk wrote (in part):

    And should we not also explore a world shaped like an egg and just as smooth looking? I am talking about Saturn’s satellite Methone, which appears to be featureless perhaps due to a thick layer of dust. Why is this?

    http://www.planetary.org/blogs/emily-lakdawalla/2012/05211206.html?referrer=https://www.google.com/

    Methone looks like (as Brother Dave Gardner might have said), “a smooth, flat, slick river rock, from where Saturn would float.” :-) Since it orbits close to Saturn, a mission to visit Methone and later ease into the rings for on-site observations of them would investigate virgin territory in that system. Also:

    I hope a Psyche mission gets approved (thank you for those links as well). It would be wonderful if Psyche turned out to be the parent body of the Canyon Diablo (Meteor Crater, Arizona) and/or the 1947 Sikhote-Alin (Siberia) meteorites, as we would already have abundant (although undocumented regarding their exact craters of origin) samples here on Earth. In addition:

    If Psyche (or other metallic asteroids) is magnetized, a spacecraft with an electromagnet might be able to brake for a soft landing–and perhaps also take off–by means of an electromagnet. (Metal PHAs–the smaller ones, at least–might be able to be moved using a smaller, electromagnet-equipped spacecraft rather than a massive gravity tractor spacecraft.) And it has the perfect ‘built-in’ mission-lobbying slogan: “Let’s get psyched-up for Psyche!” :-)

  • Harry R Ray August 29, 2015, 14:30

    MORE PINGO NEWS! Remember all those craters that kept popping up in Siberia? Sattilite photos of the exact same land masses SEVERAL YEARS EARLIER show CLEAR EVIDENCE of pingo-like structures in the EXACT SAME PLACES where the craters formed! Geologists now theorise that the ejecta AROUND these craters are a result of natural gas being RAPIDLY RELEASED (or a FULL FLEDGED EXPLOSION) when the weight of the melting pingos reached a critical minimum.

  • Harry R Ray August 31, 2015, 9:28

    Thanks, Volucris! I scanned all entries from 2,000 to 102,000. Assuming that 3.14 includes ALL cataloged asteriods with orbital period BETWEEN 3.135 and 3.144 years, I found 67 POSSWIBLE CANDIDATES. Extapolating out to one million cataloged asteroids, there is only about a 15% chance that even ONE asteroid will have an orbital period of PI(accurate to five decimal places)times Earth’s. Reflecting on this over the weekend, this would be THE BEST WAY for an extraterrestrial civilization to announce its PRESENCE to us WITHOUT giving away its LOCATION! Logically they would send MORE THAN ONE PROBE, in case any one of them encountered a micrometeroid it could not handle. If any other readers find a database with mure precice orbital periods, and find two or more “PI” asteriods, check out all of the 2.718″s(thanks, J> Jason Wentworth). Find two or more THERE, and notify The SETI Institute IMMEDIATELY!

  • Michael September 1, 2015, 5:29

    @Harry R Ray August 31, 2015 at 9:28

    ‘Reflecting on this over the weekend, this would be THE BEST WAY for an extraterrestrial civilization to announce its PRESENCE to us WITHOUT giving away its LOCATION!

    The best way to announce their presence would be a GREAT BIG SIGN on the moon facing us, ‘WE ARE HERE’. Any markings on the moon would be evident for millions of years and not subject to the erratic behaviours in the asteroid belt.