It looks like the faculae on Ceres glow in the dark, although the scientific community has decided it's brine. [What an imbecile idea, BTW!]

Would it be possible to photograph the dwarf planet and the Occator crater from the dark side?

Now, what would a photo show? Could this be done with a moderate-sized telescope from earth?

For those who doubt that the faculae glow in the dark I strongly suggest looking at the image below! Or the sequence of images of the Occator crater, further down.

So what should or could be done? Ceres' angular diameter is according to wikipedia 0.33-0.84''. Palomars 200 inch telescope or Keck or Hubble must be able to see something and settle the question, or?

Another thing; how about looking at Ceres and the faculae with a radio telescope using VLBI? With the faculae illuminated by sunlight and in darkness...


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    $\begingroup$ There is no way to see the night side of Ceres from an Earthly telescope, without moving Ceres, or moving Earth. $\endgroup$
    – notovny
    Oct 1, 2021 at 18:01
  • $\begingroup$ More information on brines on Ceres could be presented at the Modern Brines virtual conference in October 2021 $\endgroup$ Oct 1, 2021 at 18:10
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    $\begingroup$ "It looks like the faculae on Ceres glow in the dark" source? I'll edit this question to conform better to the question and answer format, see How to Ask $\endgroup$
    – James K
    Oct 1, 2021 at 20:23
  • $\begingroup$ Also the image was not of Ceres, so I've removed it. $\endgroup$
    – James K
    Oct 1, 2021 at 20:25
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    $\begingroup$ -1 For adding a troll about the scientific community. Bright spots don't glow, they are just... bright. en.wikipedia.org/wiki/Bright_spots_on_Ceres $\endgroup$ Oct 5, 2021 at 7:49

1 Answer 1


No, they don't glow. The cameras on Dawn have been set to photograph the dark grey (nearly black) surface of Ceres, and the white faculae are therefore rather overexposed. Even whe catching the setting sun, they seem to glow because they are so much whiter than everything else.

They are salts: Sodium carbonate and ammonium chloride or ammonium bicarbonate. These are white substances (sodium carbonate is washing soda, for example) This is confirmed by examining the spectrum, particularly the infrared spectrum.

The faculae have been observed by Dawn on the night side (although you don't see anything, because they don't glow.) Photos show blackness in the night time side of Ceres, just as expected.

Ceres is too small to image from Earth, even with Hubble, and VLBI is no good, because Ceres doesn't emit or reflect radio waves.

  • $\begingroup$ The albedo of Ceres is similar (almost identical) to that of Mercury and our moon. To put it simply, the surface is grey! That means that the photos that the Dawn probe took should not be that overexposed. When Dawn took pictures it just increased the time compared to what you would use when taking pics of our moon. A white surface would look white, probably similar to what the rays emanating from the Tycho crater on the moon. And they do not glow, of course! And the images of the dark side of Ceres; where are they? Is there a sequence of images taken, say once every hour, for one rotation? $\endgroup$ Oct 5, 2021 at 16:00
  • $\begingroup$ The images of Ceres' dark side are nowhere to be seen. No reply. BTW, stay tuned for my next project which is to mix white and black sand until it's grey with an albedo similar to moon sand or Ceres sand, and then make an artificial Ceres landscape (with a pile of salt as the Occator faculus) in my room and photograph the whole thing in light about as strong as that on the dwarf planet in question. Then we will see if the faculus glow in the dark! $\endgroup$ Oct 7, 2021 at 15:16

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