Starship Asterisk*

kellogg wrote:
How fast does Ceres actually rotate?

About once every 9 hours (Ceres)

The comments on the vertical exaggeration are interesting to me. As a civil engineer, all of the road designs we do (profile views) are exaggerated 10 times vertically to allow us to see very flat slopes. The use of vertical exaggeration is a well respected means of viewing topography for watershed analysis as well as determining scenic (and not so scenic) views, among other uses.

Simply put, I would have been surprised if the views did NOT have the vertical exaggeration!

ceelias wrote:The comments on the vertical exaggeration are interesting to me. As a civil engineer, all of the road designs we do (profile views) are exaggerated 10 times vertically to allow us to see very flat slopes. The use of vertical exaggeration is a well respected means of viewing topography for watershed analysis as well as determining scenic (and not so scenic) views, among other uses.

Simply put, I would have been surprised if the views did NOT have the vertical exaggeration!

I believe Google Earth defaults to a 2X or 3X vertical exaggeration, as well, unless changed. Makes sense for large planetary bodies since the vertical distance range is typically so small compared with the horizontal. Without exaggeration, most planetary surfaces simply look flat.

Chris Peterson wrote:

ceelias wrote:The comments on the vertical exaggeration are interesting to me. As a civil engineer, all of the road designs we do (profile views) are exaggerated 10 times vertically to allow us to see very flat slopes. The use of vertical exaggeration is a well respected means of viewing topography for watershed analysis as well as determining scenic (and not so scenic) views, among other uses.

Simply put, I would have been surprised if the views did NOT have the vertical exaggeration!

I believe Google Earth defaults to a 2X or 3X vertical exaggeration, as well, unless changed. Makes sense for large planetary bodies since the vertical distance range is typically so small compared with the horizontal. Without exaggeration, most planetary surfaces simply look flat.

It's got a funny way of messing with our perception of scale. We do it all the time with depictions of the atmosphere, too. I made a picture illustrating how a person might typically imagine Earth's atmosphere to be versus how it is closer to reality. It is pretty much a flat nothing against the sphere of Earth once one is far enough away that the entire sphere is in view. I think it miniaturizes planetary bodies when vertical heights are exaggerated. Seeing how thin the atmosphere is or how insignificant an otherwise tall mountain range is really puts things in perspective.

geckzilla wrote:I made a picture illustrating how a person might typically imagine Earth's atmosphere to be versus how it is closer to reality. It is pretty much a flat nothing against the sphere of Earth once one is far enough away that the entire sphere is in view.

In class, I show the kids a standard 12-inch globe, and they work out that Mount Everest at scale is about the height of the thickness of a couple of sheets of copy paper. You could feel the relief of the Earth's surface, but you couldn't really see it.

BMAONE23 wrote:Other than artistic purposes and awe factor, which work, the star field is likely there because it is expected to be visible in the darkness of space. It has been an issue here numerous times that space images don't show stars "nice image of the ISS but where are the stars".
As far as the galactic plane issue goes, nothing is stated in the write up regarding this being an equatorial orbit. Orbits can be around any axis even one that coincides with the galactic plane.

The background stars also help to give a sense of speed and motion. But you can tell the orbit of the virtual camera in the first sequence is pretty close to equatorial around Ceres, based on the way the sunlight illuminates Ceres. The alignment with the Milky Way was the first thing I noticed, and it made me look up the details to verify that Ceres's rotation is not at all closely aligned with the galaxy's.

Missed that pesky illumination angle

BMAONE23 wrote:

Cousin Ricky wrote:If this is intended to show what a flyover would look like, then why the vertical exaggeration, and why the contrived star field? In fact, this is not what a flyover would look like.

Other than artistic purposes and awe factor, which work, the star field is likely there because it is expected to be visible in the darkness of space. It has been an issue here numerous times that space images don't show stars "nice image of the ISS but where are the stars".

My question remains. If it really is intended to show what it would look like, then how is it legitimate to cater to people's misconceptions of what things look like in space? If they just wanted to make an artistic piece based on real data, or even exaggerate for visualization purposes, that's perfectly fine; but then don't say that this is what it would look like.

The answer may be in the video itself. No where on the video, the YouTube page, or the JPL site does it say that it was intended to give a realistic impression, so I must conclude that this was just editorializing done by the APOD commentator.

BMAONE23 wrote:As far as the galactic plane issue goes, nothing is stated in the write up regarding this being an equatorial orbit. Orbits can be around any axis even one that coincides with the galactic plane.

I wasn't the one who brought up the galactic plane. Since there is no indication (other than the (possibly spurious) APOD description) that the video was intended to give a realistic impression, I must conclude that the orientation of the star field is irrelevant.

Cousin Ricky wrote:

BMAONE23 wrote:

Cousin Ricky wrote:If this is intended to show what a flyover would look like, then why the vertical exaggeration, and why the contrived star field? In fact, this is not what a flyover would look like.

Other than artistic purposes and awe factor, which work, the star field is likely there because it is expected to be visible in the darkness of space. It has been an issue here numerous times that space images don't show stars "nice image of the ISS but where are the stars".

My question remains. If it really is intended to show what it would look like, then how is it legitimate to cater to people's misconceptions of what things look like in space? If they just wanted to make an artistic piece based on real data, or even exaggerate for visualization purposes, that's perfectly fine; but then don't say that this is what it would look like.

The answer may be in the video itself. No where on the video, the YouTube page, or the JPL site does it say that it was intended to give a realistic impression, so I must conclude that this was just editorializing done by the APOD commentator.

BMAONE23 wrote:As far as the galactic plane issue goes, nothing is stated in the write up regarding this being an equatorial orbit. Orbits can be around any axis even one that coincides with the galactic plane.

I wasn't the one who brought up the galactic plane. Since there is no indication (other than the (possibly spurious) APOD description) that the video was intended to give a realistic impression, I must conclude that the orientation of the star field is irrelevant.

Rather, the author of the APOD explanation was using the term "look like" as a simile, not a metaphor.
http://en.wikipedia.org/wiki/Simile

(And it certainly looks a lot more like Ceres than the Moon, irrespective of the orientation of the backdrop.)

Cousin Ricky wrote:

BMAONE23 wrote:

Cousin Ricky wrote:If this is intended to show what a flyover would look like, then why the vertical exaggeration, and why the contrived star field? In fact, this is not what a flyover would look like.

Other than artistic purposes and awe factor, which work, the star field is likely there because it is expected to be visible in the darkness of space. It has been an issue here numerous times that space images don't show stars "nice image of the ISS but where are the stars".

My question remains. If it really is intended to show what it would look like, then how is it legitimate to cater to people's misconceptions of what things look like in space? If they just wanted to make an artistic piece based on real data, or even exaggerate for visualization purposes, that's perfectly fine; but then don't say that this is what it would look like.

I think this is, in fact, what it would look like (to a reasonable approximation). While cameras capturing bodies like this record very few stars, our eyes would see the background starfield just fine, and few people would detect the difference between an actual or simulated starfield. Our brains would also likely pull out more 3D structure, making the small 2X vertical exaggeration of the video come closer to approximating our first hand view.

Can LED lighting occur naturally ?

ta152h0 wrote:Can LED lighting occur naturally ?

I doubt it. And certainly not in the sort of materials we find on the surface of solar system bodies. And not white.

UCLA-led NASA mission provides closest ever look at dwarf planet Ceres
University of California, Los Angeles | 2015 Jun 11

Cousin Ricky wrote:If this is intended to show what a flyover would look like, then why the vertical exaggeration, and why the contrived star field? In fact, this is not what a flyover would look like.

I have to agree. Go ahead and make the vertically exaggerated version (preferably with prominent text along the bottom that says so), but please also give us the non-exaggerated version. Building false intuition just creates confusion and ultimately risks turning people off to science.

and screws up the natural altimeter we all possess. I like vertical exaggeration but does that render small features invisible ?

ta152h0 wrote:and screws up the natural altimeter we all possess. I like vertical exaggeration but does that render small features invisible ?

No, if anything it makes small features more apparent. 2X vertical exaggeration probably provides a more realistic approximation of what we'd actually see with our eyes from orbit than a video with no exaggeration would. That's because we would have additional perceptual cues that the video doesn't provide.

Amazing, completely knackered that place...

The bright spots are recent impact sites.

well then, deploy the drogue chute and get down to about 25000 feet and have a look. This thing is nothing more than a standard cratered body other than the fascinating spots

Towards the end of the video, in the lower left quadrant, there is a large triangular area defined by a lightly colored 'line'. Just curious.