Starship Asterisk*

went to a seldom travelled road and drove at a specific speed noting the time it took to get to a specific tree. Went back, closed my eyes and drove the same way with my camera pointed out the window counting off the time and snapped pictures and the right moment. So I thought ! speedometer error ? Quite an accomplishment for the New Horizon's team. Mrs K now knows what bounces around in my head. By th way, I had someone steering the vehicle

I've read about that (that Wikipedia article specifically, in fact) but reading and knowing how are still two different things.

Simen1 wrote:
They probably use lots of techniques. First removing all the known disturbances like internal reflections inside LORRI and compensating for vignetting. Deconvolution are "wrapping" optical distortions backwards via advanced knowledge of how the distortions are made and computer algorithms. Then several images may be superimposed to a superresolution image. That means letting pixel grids from several images overlap to reveal features smaler then one pixel. This is not stright forward overlapping since Pluto rotates between images. Knowledge about the rotation and assuming a spheric shape is input to the computer algorithms as well as the deconvolved images. Contrast enhancement is probably used to. And probably techniques i don't know about.

All that good stuff.

They probably assume a flat spherical surface with an arbitrary distribution of albedo variation (from 0 to 1).

The blandest albedo map (i.e., the one with the minimum of total variation)
that agrees with the observations is what gets shown.

They probably use lots of techniques. First removing all the known disturbances like internal reflections inside LORRI and compensating for vignetting. Deconvolution are "wrapping" optical distortions backwards via advanced knowledge of how the distortions are made and computer algorithms. Then several images may be superimposed to a superresolution image. That means letting pixel grids from several images overlap to reveal features smaler then one pixel. This is not stright forward overlapping since Pluto rotates between images. Knowledge about the rotation and assuming a spheric shape is input to the computer algorithms as well as the deconvolved images. Contrast enhancement is probably used to. And probably techniques i don't know about.

https://en.wikipedia.org/wiki/Superresolution
http://www.oxforddictionaries.com/us/de ... onvolution

Actually hobby astronomers have some nice software tools to superresolve and reducing atmospheric disturbances "lycky imaging".
https://en.wikipedia.org/wiki/Lucky_imaging
http://www.astronomie.be/registax/

The apparent flat sides of Pluto in the new images will go away once we receive even higher resolution images. I actually have no idea how they put the images together to get this much detail out of them. If you check out the raw data, Pluto fits within an 11x11 pixel square. That's barely enough to form a smooth, round circle. How someone manages to get all the detail in the press release images is not something I understand. It frustrates me that I don't know how.

The size threshold at which a body becomes round is highly uncertain, perhaps 200-1200 km. Ref http://mel.ess.ucla.edu/jlm/epo/planet/AAS09JLM.pdf p.12

https://en.wikipedia.org/wiki/List_of_S ... ts_by_size

Pluto is almost 1200 km in diameter and thus at the high end of sizes that might not be round. Due to the high uncertainty i wouldn't rule away non-roundness completely. Defining roundness might be hard due to increasing mountain hights (in % of diameter) when the size gets smaller. I think there is a reasonable chance Pluto might have very large craters and hight featues.

Chris Peterson, perhaps. But it would be interesting to see that Pluto has been broken up by impact and it's 5 moons can be refitted to the main body like a jigsaw puzzle. We shall see.

Chris Peterson, perhaps. Unless Pluto suffered a major collision which broke it up and created it's 5 moons. Would be interesting to see that Pluto HAS been broken up and it's moons can be fitted back to the main body like a jigsaw puzzle. We shall see.

thank you for the answer.

montylc2001 wrote:Everyone keeps saying that the contrast differences and low resolution cause Pluto to have a lumpy appearance, but I tend to disagree. The more I study the newest pictures the more obvious to me that Pluto has a large chunk missing. Of course, I could be wrong, and the next few weeks will tell the tale.

You are almost certainly wrong. A body of that mass has to be spherical to a high degree, and within the resolution of the current images.

Everyone keeps saying that the contrast differences and low resolution cause Pluto to have a lumpy appearance, but I tend to disagree. The more I study the newest pictures the more obvious to me that Pluto has a large chunk missing. Of course, I could be wrong, and the next few weeks will tell the tale.

I think its a too interesting thought to skip. Let me try four scenarios:

1.1 New Horizon is passing by a California Air Base at 10 000 km distance (same as New Horizons will pass Pluto) at a speed of 13,8 km/s. In comparison ISS is in a low earth orbit currently about 355 km altitude and 7,66 km/s speed. ISS is roughly 110 x 70 meters. New Horizons is considerably smaller with its roughly 2 x 2 meters, at a much larger distance, thus having an apparent magnitude far less then ISS. Roughly 2,4 million times (16 magnitudes) fainter. ISS have a maximum apparent magnitude of -4. New Horizons would be +12 magnitudes. The limit of the naked eye is about +6,5 magnitudes, making it invisible to the naked eye by a large margin. ISS is fast moving but not too fast for us to see. New Horizons would appear about 20 times slower do to the 35 times larger distance.

1.2 If New Horizons was passing closer, lets say at 100 km above sea level without disintegrating it would outspeed ISS by 6,4 times. No problem so far. But it would be about 150 times (6 magnitudes) fainter then ISS (ignoring friction glow). At magnitude +2 it would be visible to the naked eye assuming it would be fully sun lit when the sky is dark enough.

2.1 If you where standing at the night side of Pluto looking for a "full moon" New Horizons it would be far fainter then in scenario 1.1 due to Plutos large distance to the sun. At Plutos current distance of 32 AU it will receive about 1/1000 the light per area then it would around earth. Even with a large telescope it would be out of reach.

2.2 If it was passing closer to you standing on Pluto it would be brighter but sweep trough your field of view faster. If it was close enough to be visibly bright (+6,5 magnitude at 30 km) then it would sweep trough the field of view in a few seconds so you would probably not notice it. At 3 km and +1,5 magnitude (equaling the maximum brightness of Saturn) it would sweep through the field of view in a fraction of a second.

I have not double checked the calculations so please correct me if necessary.

ta152h0 wrote:not quite ready to let go just yet. I saw a vid of an SR71 buzzing a famous Calivfornia airbase and then they showed the airplane go a max speed simply by speeding up the video. I was wondefring if the same could be done to speed the sr to 30000 mph and if the human senses could see that ?

New Horizons will pass Pluto at about four times the top speed of an SR71. Of course, you could speed up a video to see what that would look like in terms of simple speed. It doesn't reflect reality, however. If New Horizons were actually at ground level, it would explode almost instantly due to the drag forces. Spacecraft which are observed burning up are doing so 100 km high, where there's almost no atmosphere (but still plenty to ablate away their structure).

ta152h0 wrote:not quite ready to let go just yet. I saw a vid of an SR71 buzzing a famous Calivfornia airbase and then they showed the airplane go a max speed simply by speeding up the video. I was wondefring if the same could be done to speed the sr to 30000 mph and if the human senses could see that ?

It's not so much about what the human senses can see, as it is about what the human brain can comprehend.
Unfortunately, the average human can't seem to comprehend ....much.

(sorry...tough day here)

not quite ready to let go just yet. I saw a vid of an SR71 buzzing a famous Calivfornia airbase and then they showed the airplane go a max speed simply by speeding up the video. I was wondefring if the same could be done to speed the sr to 30000 mph and if the human senses could see that ?

robolt wrote:They "...orbit around their center of mass..." Don't ALL gravitationally linked objects orbit around their respective centers of mass?

Yeah, but the Pluto-Charon system has a center outside the larger body of mass. It's not something we get to see frequently. I think it may be the only instance of it in our solar system, excepting perhaps some kind of binary asteroids, which I've never heard of, but I mean we have hardly looked at all the asteroids out there.

They "...orbit around their center of mass..." Don't ALL gravitationally linked objects orbit around their respective centers of mass?

See the Dogwood around back

can one get NASAtv on DirectTv feed ? Do I need to bark at a different tree ?

Some of the freshest images of Pluto are available in today's press release and they compare the lumpy-looking first images to very much spherical ones now that more detail is available to banish the optical illusion.
http://www.nasa.gov/feature/nasa-s-new- ... r-to-pluto

Deconvolved. Now there's a word not used by many in my day-to-day world. When I looked at the video, the first thing I noticed was the wobbly motion of Pluto around the center point of mass. I suppose the mathematicians are looking forward to getting better detail along with a whole lot of others. Or are we going to really going to get that much more information about density differences than we already know? I mean – just from a better knowledge of the orbits.

Edit- Very informative press conference. If the simulation is correct and there were many foreign bodies in orbit (as may have been seen around Ceres), I wonder if collision avoidance is much of a worry?

https://cosmosmagazine.com/space/knocking-plutos-door

http://www.bibliotecapleyades.net/unive ... mos186.htm

ta152h0 wrote:if I was standing at a famous California airbase and New Horizons would perform a 30000 mph " rasante :. what would it look like ?

That's 14 km/s. This is at the low end of the speed range for meteors on the Earth. And about twice the speed of re-entering space junk.

What it would look like is a burning, disintegrating trail of debris.

The time laps is over a month old. When do we get the next better image? Is there a ETA list of images so i can mark my calendar? Or does New Horizons use all its 228 Watts of power to observe and save power for transmitting after july 14?

This is amazing! I have been excitedly looking forward to this since 2006! I wonder what things New Horizons will show on Pluto and its moons?

As a color commentator, it is quite clear what I want to know about Pluto.

Previous images and illustrations have hinted that Pluto is considerably redder than its large moon Charon. See here, here, here, here, here, here, here and here. I have been wondering if there really is such a big difference in hue between Pluto and Charon, and if so, why it is so.

Admittedly, the very latest color images of Pluto and Charon suggest that they are the same hue. See here.

Ann