APOD: Approaching Pluto (2015 May 27)

[APOD Robot]

Approaching Pluto

Explanation: Here comes Pluto. NASA's robotic New Horizons spacecraft is now beyond the orbit of Neptune and closing fast on the Solar System's most famous unexplored world. The featured time lapse video shows Pluto and Pluto's largest moon, Charon, orbiting their common center of mass in 13 frames taken from April 12 to April 18. Although blurry, images in the video now rival even the best images of Pluto yet taken from Earth. New Horizons remains on schedule to zoom past the distant dwarf planet on July 14.

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[ta152h0]

please, please have bright spots

[BMAONE23]

48 days to go

[geckzilla]

please, please have bright spots

What will you do if there are only dark spots?

[ta152h0]

if I was standing at a famous California airbase and New Horizons would perform a 30000 mph " rasante :. what would it look like ? edit. my laptop has serious keyboard issues

[ta152h0]

then Pluto and Ceres are unrelated

[Boomer12k]

Amazing... Can't wait for a gooooood shot.....

:---(===) *

[sheriffofnothingham]

Looks as though Pluto is non-spherical in shape. The shape of Charon appears quite irregular as well. As if an ancient massive object slammed into the premordial Pluto and split it into two objects - the Pluto of today and Charon. With the nearly 19000 km distance between Pluto and Charon, the moon would appear as a disk approximately 3.33 degrees in the sky; this more than 10 times the angular size of the Moon from Earth. Computer programs would have been sufficient to study the orbital dynamics of the Pluto-Charon system in detail. The value of a mission to the Pluto-Charon system is in the observation of gravitationally locked bodies. Although both bodies appear somewhat non-spherical this should not dissuade real estate venturers from plotting a course for the sale of plutonian plots. I would opt for a location which has a view of Charon above the horizon.

[geckzilla]

Pluto is most likely spherical. It's the high contrast regions which create a very strong illusion that it is not.

[Ann]

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

[starsurfer]

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?

[SimenO1]

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?

[Chris Peterson]

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.

[Ron-Astro Pharmacist]

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

[geckzilla]

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

Click to view full size image

[ta152h0]

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

[BMAONE23]

See the Dogwood around back

Click to view full size image

[robolt]

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

[geckzilla]

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.

[ta152h0]

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 ?

[Craine]

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)

[Chris Peterson]

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).

[Simen1]

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.

[montylc2001]

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.

[Chris Peterson]

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.