NASA Dawn, What will it discover about Ceres?

I believe your still frame from the latest series of animated images has the bright spot in it, top, center. It's in the correct area of the planet, and rotates along the expected path. It does look different in the latest images, than it did before. Overall, it's still much brighter than the surroundings, but not as bright. I expect the bright little spot near its center was smeared out over a wider area in the previous, lower resolution images, giving a higher brightness.

NASA has just released two new images of Ceres, taken by the Dawn space probe on Feb. 12th. They show a number of craters not seen before, particularly on the shadowed right hand side.
The much-talked-about 'bright spot' can still be seen in the right hand image. Even though greater resolution nearly removes pixelation artifacts, the bright spot still looks rectangular, with the long axis roughly vertical. It appears to be about 20 by 30 miles across. It remains the most conspicuous feature on the planet. Link to images, below:
www.jpl.nasa.gov...

a reply to: Ross 54

I see several bright spots. Some are larger than others; some are more round-ish; some are oblong-ish; and some are irregular.

I see what may be a large one on the far far "western" limb along the equator of the right-hand image (and only when I enlarge the image), but considering its location on the limb relative to the camera, it would be foreshortened, and thus impossible to discern its true size and shape

Which is the "original" bright spot that was visible at a distance?
Can you please point it out?

Thanks in advance.

In these newer pictures there is much more resolution. I seems obvious that they are newer craters, and appear much like what newer craters look like on our moon. The impacts exposes lighter material beneath, and gradually, cosmic rays and solar wind darken them all to a dull grey.

originally posted by: Box of Rain
a reply to: Ross 54

I see several bright spots. Some are larger than others; some are more round-ish; some are oblong-ish; and some are irregular.

I see what may be a large one on the far far "western" limb along the equator of the right-hand image (and only when I enlarge the image), but considering its location on the limb relative to the camera, it would be foreshortened, and thus impossible to discern its true size and shape

Which is the "original" bright spot that was visible at a distance?
Can you please point it out?


Thanks in advance.

The first-detected, and still most conspicuous bright spot is in the top left quadrant of the right hand image, of the two. It's not too far from the edge of the planet's image. It's readily visible, even without magnification.
Judging by the previous animated sequences of the spinning planet, its at a high latitude. The shape appears approximately rectangular to me. The flat edge along the left facing side is the easiest to see.
As I understand it, on a sphere, it seems that an object is horizontally elongated if it is on a surface that is well above or below the point of view. An object will appear vertically elongated if well to the right or left of center.

The object we are considering is both above and to the left of center, and about the same distance in each. These two distortions should, it seems, substantially cancel each other out.

originally posted by: Ross 54
The shape appears approximately rectangular to me. The flat edge along the left facing side is the easiest to see.

Hmmm. Maybe.

However, I think for right now it's only an overexposed blob of brightness whose true shape cannot yet be discerned.

WAIT THERES MORE !!!!

Just seen on "NASA.gov/ceres" about the bright spot on Ceres having a COMPANION ...

Dwarf planet Ceres continues to puzzle scientists as NASA's Dawn spacecraft gets closer to being captured into orbit around the object. The latest images from Dawn, taken nearly 29,000 miles (46,000 kilometers) from Ceres, reveal that a bright spot that stands out in previous images lies close to yet another bright area.
"Ceres' bright spot can now be seen to have a companion of lesser brightness, but apparently in the same basin. This may be pointing to a volcano-like origin of the spots, but we will have to wait for better resolution before we can make such geologic interpretations," said Chris Russell, principal investigator for the Dawn mission, based at the University of California, Los Angeles.

The images that they have put up are a lot clearer as well...




Gonna make a new thread about this .... but i still not hit my 20 yet so i cant just yet.. and i cant even add an image to here

a reply to: raikata

So the bright spot (well, spots) is inside the crater.

Still a mystery why it's in this crater specifically and in none others.

a reply to: swanne

"Ceres' bright spot can now be seen to have a companion of lesser brightness, but apparently in the same basin. This may be pointing to a volcano-like origin of the spots, but we will have to wait for better resolution before we can make such geologic interpretations," said Chris Russell, principal investigator for the Dawn mission, based at the University of California, Los Angeles.

I think these might be ice geisers.

a reply to: wildespace

could be the same phenomena we see on Saturn's moon Enceladus.
www.jpl.nasa.gov...

Great discovery adventure, and I hope folks notice, strange images released immediately.

March 6 [orbit arrival] is not a boundary date, the probe is using an ion engine to slip into a stable orbit and is currently drifting past it and farther away and will then approach from down sun, with a crescent Ceres all that is visible.

It will wind up in a polar orbit, fortunately Ceres axis is only 4 deg to the ecliptic, and its day is 9 hours long, so almost all except close to the south pole [where it's now winter] will be visible.

originally posted by: JimOberg
Great discovery adventure, and I hope folks notice, strange images released immediately.



March 6 [orbit arrival] is not a boundary date, the probe is using an ion engine to slip into a stable orbit and is currently drifting past it and farther away and will then approach from down sun, with a crescent Ceres all that is visible.



It will wind up in a polar orbit, fortunately Ceres axis is only 4 deg to the ecliptic, and its day is 9 hours long, so almost all except close to the south pole [where it's now winter] will be visible.

Previously Dawn had visited another of its primary scientific objectives, the asteroid Vesta.
www.gizmag.com...

Over the course of its year-long mission, the orbiter snapped an impressive 30,000 images of the rocky body, discovering much about the formative period of the early solar system along the way. Undoubtedly, a similar analysis of the dwarf planet Ceres will unlock the secrets of the white spots, and a great many other things as it completes its epic mission.

originally posted by: wildespace I think these might be ice geisers.

originally posted by: intergalactic fire
a reply to: wildespace

could be the same phenomena we see on Saturn's moon Enceladus.
www.jpl.nasa.gov...

From page 1 of this thread...

originally posted by: JadeStar
My educated guess is that they will find Ceres has spots where liquid water from below the surface has oozed up and frozen.

Just sayin

Is liquid water inside Ceres even possible? Would an object that small have an internal heat source when there is no large body close by to cause tidal flexing? I guess the only possibility would be the decay of radioactive elements in the core.....

The usual model of Ceres has it with a rocky core, surrounded by an ice layer, covered over with a thin crust of rock and dust.
The bright spot is currently reported to have an albedo (reflective brightness) of 40 percent.
The maximum albedo of ice over a solid surface, such as glacial ice on Earth, is 20 to 40 percent.
We can assume that the bright spot is smaller, and so, brighter than it appears. It is reportedly not properly resolved in the latest images.
By this we can assume that the albedo is above 40 percent, which seems to rule out the sort of ice we might expect to find on Ceres' surface.

originally posted by: Ross 54
We can assume that the bright spot is smaller, and so, brighter than it appears. It is reportedly not properly resolved in the latest images.
By this we can assume that the albedo is above 40 percent, which seems to rule out the sort of ice we might expect to find on Ceres' surface.

I'm not sure if I agree with your reasoning about why the albedo would be over 40. Sure -- the bright spot(s) could end up being smaller than they appear now, but that doesn't mean they would be brighter; they can be smaller and have the same albedo. For example, it may really be (say) 2 pixels x 2 pixels rather than 4 pixels x 4 pixels, but each pixel could still have the same brightness.

But OK -- let's say the albedo is slightly higher than 40. Even then, I think it is far too early to rule out that there could be a fresh supply of ice being brought to the surface via some geologic process (e.g., vulcanism), especially considering Ceres seems to have a relative abundance of water ice, and water vapor (from some source) can be found in Ceres' atmosphere.

I'm not saying it is water ice, because I don't know what it is. However, I think it's also premature to say that it can't be water ice. That's just one of many possibilities for what the bright spots are that would be premature to close our minds to.

I know there are inconsistencies with it being water ice, based on what we currently know about Ceres, but the key word there is "currently". When we actually get to Ceres and investigate it with the instruments on Dawn, what we "currently" know about it will change.

Let's actually investigate the spots with better data and more instruments before we begin to "rule out" certain things by simply looking at a picture from 30,000 miles away.

For a given of light output, a 2 by 2 unit object, total area 4, would need , it seems, to be four times brighter than if the same object was 4 by 4 pixels, total area 16.
I base this on the fact that in asteroid work, the size estimate of a distant body is based on observed brightness, at an assumed reasonable albedo. If it turns to have a lighter color, the size estimate would need to be reduced, if darker, increased.

When are new pictures supposed to be released?

The newest images were taken on Feb. 25th. They will presumably be released within a few days. The last images were released after a delay of 6 days. If that holds true in this case, they will be made available on Tues., March 3rd. The new images will offer a 33 percent improvement in resolution.
The Dawn probe is slowly curving around Ceres, on its way to establishing orbit. The new pictures will be of a planetary disk only about 44% illuminated by the Sun.
It's not clear if the much-discussed bright spots will be in the lighted part, or the dark. If these spots are merely reflective, and in the dark, they will presumably be invisible. If they are self-luminous, they may well be seen under these conditions.
These images will be the best we will see until April. Dawn will swing wide of Ceres during March, before settling into orbit in the latter part of next month. Better images of Ceres should again become available some few days after April 10th.