Updates Dawn Mission News

[boogabooga]

Id like to know why Ceres looks so much like Umbriel

Has anyone ever seen them at the same place at the same time? :lol:

 

[ISProgram]

IMO, I think it's a fresh impact crater. Aristarchus on Luna comes to mind.

It could be the Piazzi feature...

 

[Unstung]

My guess is also that the bright spot is a fresh impact crater, but in this case it might have exposed subsurface ice. The ice is sublimating into space and results in the water vapor that has been detected around Ceres.

 

[fsci123]

I heard some people say that Ceres it's more in common with Callisto and Ganymede than any other body. Perhaps the ice exists on the surface.

 

[Kyle]

It could be the Piazzi feature...

I'm positive it is.

 

[Unstung]

This is unexpected.

JPL: "Gullies on Vesta Suggest Past Water-Mobilized Flows"

Protoplanet Vesta, visited by NASA's Dawn spacecraft from 2011 to 2013, was once thought to be completely dry, incapable of retaining water because of the low temperatures and pressures at its surface. However, a new study shows evidence that Vesta may have had short-lived flows of water-mobilized material on its surface, based on data from Dawn.

"Nobody expected to find evidence of water on Vesta. The surface is very cold and there is no atmosphere, so any water on the surface evaporates," said Jennifer Scully, postgraduate researcher at the University of California, Los Angeles. "However, Vesta is proving to be a very interesting and complex planetary body."

The study has broad implications for planetary science.

"These results, and many others from the Dawn mission, show that Vesta is home to many processes that were previously thought to be exclusive to planets," said UCLA's Christopher Russell, principal investigator for the Dawn mission. "We look forward to uncovering even more insights and mysteries when Dawn studies Ceres."

[...]

---------- Post added 01-31-15 at 01:14 AM ---------- Previous post was 01-30-15 at 09:49 PM ----------

But people just want more photos of Ceres now. So below is a table, provided by Marc Rayman, that shows what to expect from Dawn's cameras until the spacecraft begins the third rotation characterization (RC3).

RC1 at Vesta for reference:

 

[fsci123]

Ceres at the closest level yet. My god we can see craters

Will update when in better internet connection.

---------- Post added at 02:54 PM ---------- Previous post was at 10:50 AM ----------

If you look closely at the white spots, you can see streaks. They are most likely fresh and large impact craters. That one crater on the south has a small mountain inside of it.

 

[Unstung]

Sources and more information:

Dawn Mission: "Dawn Getting Closer Views of Ceres"

The above chart's predictions regarding resolution turned out to be accurate, but the pictures are reported to be taken on February 4 rather than the third. "At a resolution of 8.5 miles (14 kilometers) per pixel, the pictures represent the sharpest images to date of Ceres."

JPL has the same blurb written about the new images.

Discovery News: "Craters Pop as NASA's Dawn Probe Approaches Ceres"

But as this most recent series of observations show, Ceres has a varied surface apparently covered in impact craters. In the dwarf planet’s south polar region, for example, a large, well formed and approximately circular impact crater can be resolved.

The mysterious bright feature that has fascinated planetary scientists is still there and slowly beginning to reveal some detail. What's more, there appears to be several more smaller bright features -- could they be indicative of ice accumulations or some subsurface mineral exposed by impacts?

[...]

 

[fsci123]

New sharpest image yet. Enjoy.

Dawn captures sharpest image yet

Craters and mysterious bright spots are beginning to pop out in the latest images of Ceres from NASA's Dawn spacecraft. These images, taken Feb. 12 at a distance of 52,000 miles (83,000 kilometers) from the dwarf planet, pose intriguing questions for the science team to explore as the spacecraft nears its destination.

 

[ISProgram]

I don't suppose Dawn has a color camera on it?

Ceres has a radically different color than other asteroids, but it looks almost the same with grayscale on. Like a certain Uranian moon, in fact.

 

[Unstung]

I don't suppose Dawn has a color camera on it?

Ceres has a radically different color than other asteroids, but it looks almost the same with grayscale on. Like a certain Uranian moon, in fact.

Dawn has a filter wheel like many other planetary spacecraft. The photos of Ceres so far have probably been taken through the clear filter. Dawn needs to take a composite to simulate color.

 

[fsci123]

With all the advances in camera technology. One would think that nasa would be able to harden an 4khd color canon camera and send it up with the craft for at least half the cost.

 

[sorindafabico]

With all the advances in camera technology. One would think that nasa would be able to harden an 4khd color canon camera and send it up with the craft for at least half the cost.

Why would they send two cameras if the monochromatic camera is able to do both jobs using filters?

 

[RisingFury]

With all the advances in camera technology. One would think that nasa would be able to harden an 4khd color canon camera and send it up with the craft for at least half the cost.

Commercial cameras don't come anywhere near the quality of spacecraft cameras.

As for a higher resolution camera - more pixels won't do much for you if the optics begin to be the limiting factor. And when it comes to optics, size does matter.

 

[Unstung]

With all the advances in camera technology. One would think that nasa would be able to harden an 4khd color canon camera and send it up with the craft for at least half the cost.

The problems with shooting 4K video are having new technology radiation hardened, being able to transmit all the high resolution video, and the added mass from carrying an instrument whose purpose cannot be adequately justified. It already takes a significant amount of time to download non-moving images from spacecraft that are up to billions of kilometers away. There is not any scientific justification to shooting regular 4K video and it will just hurt the overall data return. The ability to return more data will come with optical communication, but shooting video in space is still not very useful.

Don't forget that shooting regular video in space will require relatively short exposure times because there are usually 24, 25, or 30 frames per second in a video. It will further limit any useful data that can come from a video camera. Also, target objects in space often appear to move relatively slowly from the vantage point of a spacecraft. As a result, telescopes can be used with relatively long exposures without much worrying about motion blur.

Science cameras often have filters and specially-designed sensors to cover several important wavelengths. Some of them can collect gigabytes of data in a single image, but for a good reason. Cameras used on science missions must be thoroughly calibrated so the measurements are as accurate as possible. Typical off-the-shelf cameras are not designed to make that kind of detailed scientific measurements.

Keep in mind that the camera Dawn uses is 1 megapixel, compared to 8+ megapixels 24 times a second to shoot 4K video. Although Dawn's camera has fewer pixels, each pixel can store much more data than a consumer camera.

As a side note, Canon does not offer any lightweight, consumer 4K cameras.

tl;dr: Shooting 4K video on a science mission is pointless.

 

[fsci123]

I wasn't talking about transmitting video...im aware of the data limitations that live streaming has. I just thought it would be easier to retrofit one of those national geographic style cameras(the ones that take pictures of wildlife) instead of building one from near scratch.

 

[fsci123]

So I was photoshopping an image of Ceres for my project when this popped up. Coincidence? I think not.

Bright spot has dimmer companion

These images of dwarf planet Ceres, processed to enhance clarity, were taken on Feb. 19, 2015, from a distance of about 29,000 miles (46,000 kilometers), by NASA's Dawn spacecraft. Dawn observed Ceres completing one full rotation, which lasted about nine hours.

Uncropped images.

---------- Post added at 01:41 PM ---------- Previous post was at 11:07 AM ----------

I think it shows the bright spot contrasted.

Looks like it's only a few miles across or smaller... I'm placing my bets on a geyser again...

 

[Unstung]

Something to note: The photos taken on February 19 were from RC2. Today, the 25th, Dawn is expected to take another series of images during OpNav 4. Dawn will not take any photos of Ceres from March 1 to mid-April when it gets captured by Ceres' gravity and thrusts to RC3. During that time, Dawn would not be able to resolve much more detail in Ceres anyways. So it's going to be nearly two months from now until Dawn's view of Ceres significantly improves.

 

[Unstung]

There's some new media, although the best resolution of Ceres remains pretty similar.

L to R: A map projection, Full rotation animation, Crescent Ceres on 25 February

|

|

JPL: "NASA Spacecraft Nears Historic Dwarf Planet Arrival"

There's a couple new videos that have a useful 3D animation of Dawn entering orbit:​

And a full press briefing:​

[ame="http://www.youtube.com/watch?v=sJr-pctUYdw"]Dawn Ceres Arrival[/ame]

 

[Cosmic Penguin]

Looks like I didn't pay enough attention to Dawn with respect to some other planetary exploration probes (already did when it was at Vesta) - I thought that March would be the big month for Ceres, however it turns out that while Dawn will enter orbit in 3 days time, the orbit would sweep across the night side until April so better images and observations won't come till then (well, not for the GRaND particle sensor....).