The Icy Mountains of Pluto | Hacker News Reader

The Icy Mountains of Pluto

nasa.gov

591 pointsThorondor136 comments

Interestingly, they don't look like mountains formed by collisional or extensional tectonic processes to my eye (a geologist who studies mountain formation). They look sort of like diapirs (i.e. lower density material pushing up through a higher-density medium; frozen methane and nitrogen are both less dense than water ice[1]) or vaguely like eroded volcanoes, but without obvious vents. Very different erosional processes could explain some of it, but it certainly doesn't look like typical plate-tectonic or ice-sheet topography. Super cool!

[1]: https://extras.springer.com/2006/978-1-4020-4351-2/Jenam/Ses...

So Pluto wears diapirs. Ha Ha.

Actually, that's really interesting. I had no idea there was such a thing as a diapir. Your comment on eroded volcanoes made me wonder if water on Pluto acts a lot like rock on Earth and if there are water volcanoes that result from sub-surface heat transforming water into liquid.

if you are interested read some stuff on the subject, there is loads of it around...

ice is a sort of equivalent to rock beyond a certain (not as far as pluto by a long way) distance from the sun.

astronomers have a funny idea about what the word ice means too...

Probably a naive question, but why is it the case? we have the basic formula of thermodynamic: PV = nRT, with n and R being constant, so if I keep the volume the constant and decrease the temperature, it would decrease the pressure P, making the material less hard. What am I missing?

PV = nRT is for ideal _gases_, ice is solid.

phase transitions are complicated. when something is a gas that rule applies because the forces between the constituent particles are neglible except for the electromagnetic interaction causing scattering (i.e. particles bouncing off each other, or the surroundings).

this is the pressure from that formula. increasing temperature increases the energy in the system, resulting in more collisions, and more pressure. decreasing it results in less as you correctly point out.

in a solid the electromagnetic interaction is constantly present and locks the constiuent particles nearly in place, so that when excited they 'vibrate' around their location, rather than moving freely like in a gas. this has different consequences, so that decreasing the temperature will increase the rigidity of the material since the particles will become ever less likely to achieve the energy required to escape their electromagnetic 'traps'.

Postulating here: Is it possible the mountains are a result of gravitational pull of Charon on Pluto's water-ice mantle during pluto's formative years? Or the gravitational affects of Neptune and Pluto's orbital resonance?

The surface appears to be extremely young. There are no craters on these mountains. They're apparently made of ice and are relatively tall.

http://www.nytimes.com/2015/07/16/science/pluto-flyby-photos...

"But these mountains are almost certainly made of frozen water instead of rock."

Keeping in mind that I don't know anything about Charon's orbit or gravitational effects, I think it's possible. It also doesn't have to be early in Pluto's formation, either; it can be a slow, continuous, ongoing process. Salt diapirs on Earth move up through the brittle crust and 'erupt' on the surface.

> during pluto's formative years?

I believe they're saying that this is not the case since they've seen fewer craters on Pluto than they would have expected, which makes them think these mountains are relatively 'recent' formations (that would have hidden any older craters that were present).

how would gravity do this?

orbital trajectories are in free fall... tidal effects are all that are left and they are huge, smooth gradients, not tiny highly variable things of the sort that could create surface features like this.

Tidal forces do serve as an energy source to drive other geological mechanisms, however they stated in the press conference that Charon is to small to do this, so we need to find another mechanism for how Pluto is still active.

Waves on a sea are caused by gravity so it's not a bizarre idea.

https://en.wikipedia.org/wiki/Gravity_wave

That's amazing.

The photo of Charon might be the most straight-up gorgeous of the lot so far:

https://www.nasa.gov/image-feature/charon-s-surprising-youth...

At least to my eye. It's just such a classic shot of a world.

Anyway: USA! USA! (I kid!) Go humanity!

USA! USA!

I've seem comments on here that it's not OK to say that, but if you are a US citizen then I think you damn well should be proud of this and I'll applaud anyone who makes space work. It's frikkin' hard.

When I see a Soyuz launch I think "Go, Russia" and I felt similar things when India, China or Japan launch rockets. Just today Ariane put a satellite in space. Go, Europe!

Hell, as a Brit I'm proud of Prospero: https://en.wikipedia.org/wiki/Prospero_(satellite)

Absolutely. We're proud of our football teams, why not be proud of our space teams? I only wish we could stir the general public to equal levels of excitement for space as we can for sport.

> We're proud of our football teams, why not be proud of our space teams?

Because at some point we realized that we can only be proud of our own achievements.

Sadly most people never realize that and so they root for nations, sport teams and so on as a supplement. Mostly to identify with and also (in this process) to put others down.

We (or most of us) need an identity and most of us never develop one for ourselves, that does not need an outside entity to feel strong/good/important/validated enough.

Nations should die and not exist. Shouting nations names with pride is shameful and dumb. Nationalism kills. It’s an awful, toxic ideology.

Death to all nations. May no nations exist in the future.

(If you get to spew your ideological bullshit I get to spew my own deeply held and utterly impractical ideological bullshit believes. No, seriously, I want nations to not exist eventually. I think the world would be vastly better without them.)

I'm curious if, as an alternative, you'd rather see decentralization (smaller population units), some kind of global superstate, or something else entirely?

We've all seen the poisons of nationalism, but I wonder if what one might call "tribalist" tendencies are so easy to vanquish - assuming one even wants to.

> I've seem comments on here that it's not OK to say that,

Oh man. My kingdom for this thread not starting again.

Better than shouting would be to actually push legislators to fund space programs better. Most of these programs are run on less than 1% of overall government budgets.

Shouting seems like a good way to do that. Political machine in western countries is focused on pandering to the public, so if public (shows that it) wants space, space they'll get.

Because realy, it is an exclusive either-or choice between shouting or pushing for better funding?

Or.. Both?

Minor correction: Ariane -> ESA (European Space Agency). Ariane is the name of the rocket (and 'Arianespace' the name of the company that does the actual launching for ESA, but that's just part of ESA with a different name).

BTW, I saw they have a Soyuz manual on their website: http://www.arianespace.com/launch-services-soyuz/Soyuz-Users... [pdf]

> Anyway: USA! USA! (I kid!) Go humanity!

Well it was a grand old dick-waving contest in the 60s. Why not now as well.

But think of how it drove progress!

Seriously, would we have expended even a tenth of as much energy into building the rocket technology to go to space, without the nationalistic prestige race in the 60s? Or the idea that we could use them to lob nuclear holocaust at each other if shit hit the fan?

I'll take Nationalism + Badass space exploration over Kim Kardashian + Autotune any day of the millennium.

I just wish we'd have dropped a US flag onto Pluto. Nothing like envy to make someone else achieve something great!

Dropping a US flag onto Pluto, at 14 Km/s, would have had the effect of a small nuke. :)

What about, dropping Christopher Walken onto Pluto?

> I'll take Nationalism + Badass space exploration over Kim Kardashian + Autotune any day

Kim doesn't have a long track record of leading to war and genocide. Nor do autotune and badass space exploration (yet).

Maybe humanity needs to live under a threat of annihilation in order to get its collective shit together? It's a thought that comes to my mind every time I open a news site.

Not visiting websites that you don't like has the effect of making you less cynical IME.

it wasn't the dick waving bits that drove progress. it actually postponed it in many areas... that apollo program was damned expensive relative to the technology that came out of it. a gigantic vanity project.

that whole man on the moon business is really quite dumb (although impressive) compared to the robotic probes we use today, which are what the soviet union was pioneering at the time... all that dick waving stopped them from doing it sooner.

Probes are good for exploration, but colonies are useful too, and it's a shame that we stopped putting in nearly any effort along those lines.

but the problem was that we reversed the order. We should have gone to moon in the late 80s rather than build the shuttle, after having built a ton robotic probes and having much better automation. Imagine where we would be if we'd had a sustained 10-50 Billion /year increase in AI and robotics over the past 50 years. But because we pushed manned systems first, we both became disillusioned at the cost/benefit ratio and made that ratio worse by becoming very concerned about human life risk. And thus we lost momentum - budgetary, career-wise in engineering, public sentiment, political support ... On the other hand - I am a big supporter of the Goldin era "Faster, Better, Cheaper" approach. We got more done even with a 50% failure rate, and at half the cost - just by flat out doing more.

The most exciting part is the following:

"The close-up image was taken about 1.5 hours before New Horizons closest approach to Pluto, when the craft was 47,800 miles (77,000 kilometers) from the surface of the planet. The image easily resolves structures smaller than a mile across."

At its closest, the probe was 7,800 miles away, so we're going to get images way clearer than this in the following days, and even this is amazing to look at.

It will take approx 16 months to transfer all the pictures it took, because it is transmitting at only 1 kbit/second.

http://www.planetary.org/blogs/emily-lakdawalla/2015/0130080...

> because it is transmitting at only 1 kbit/second.

I read elsewhere that it's also because other projects need to use the Deep Space Network, and bandwidth is a little constrained.

This is true. Communicating with New Horizons requires using the 70m DSN dishes. Of which human civilization has built ... 3. So monopolizing that resource for an entire year would be problematic. Instead the probe will send back highly compressed gallery sheets of all the images it has as well as a few pre-selected shots (some of which we've seen) which the science team will use to prioritize the data the gets sent back. Then the highest priority images will be transmitted using loss-less compression and the remainder will get sent over the remaining months off and one when the 70m DSN dishes aren't needed elsewhere.

> monopolizing that resource for an entire year

These dishes all look in different directions, so 2 out of 3 wouldn't even be able to communicate with the probe most of the time.

Sort of, but keep in mind that if another probe is in a similar part of the sky as New Horizons then they will compete for dish time.

Maybe its time to build more then. It seems silly to be bottle-necked on things like this.

Lots of missions and mission phases don't require bigger antennas. Look at http://eyes.nasa.gov/dsn/dsn.html for current usage of the Deep Space Network. As I type this, 3 smaller dishes in Goldstone are handling 4 Mars missions, all solar powered, Odyssey at 14.22 kb/s. At Canberra, the only active dish is a small one, receiving data at 159 b/s from Voyager 2 (!). Which, I grant, doesn't have a lot to say right now.

3 sites, 1 big dish and 3 smaller ones at each, except for a 4th smaller one at Goldstone, that's a serious investment and I gather enough for now, especially since satellite technology now allows storing massive amounts of data (8 GB for New Horizons) for download as the mission and ground stations allow. Note also that after New Horizons finishes downloading the data from its flyby in November 2016, it won't have a lot to say unless and until its Kuiper belt object flyby.

Fair enough. I had not realized that NH could send data at a faster rate when bandwidth was available. I wondered about the point of having 8 gb storage when you had such low speeds - it would take years to download.

As for the storage capacity, that's dictated by the amount of science collected. Who cares how long it takes to download?

It's taken 11 years from mission inception for New Horizons to get built, launched, and get to Pluto. What's a year or two more?

Eventually, a lot of spacecraft communications will switch to optical systems instead of using radio. The major gating factor there, at least in regards to solar system exploration, is the creation of off-Earth infrastructure to facilitate it. Which likely would be just a small fleet of relatively modest sized space telescopes designed for 2 way communications. Having the infrastructure off Earth would mean that it would be insensitive to weather and would also be easier to maintain contact with spacecraft nearly anywhere in the sky at any given time. Building that infrastructure probably won't happen until launch costs fall but realistically it's something that could easily happen in the next decade or so.

And then the available bandwidth goes way up.

Your linked article says 2 weeks, not 16 months.

11 photos a day.

I don't know why that article quotes two weeks. I've read the 16 months figure in several places and it was mentioned in the press briefings yesterday. There might be a specific subset of data that will take two weeks to get. Perhaps the low-res JPGs of all of the planet imagery.

That article says two weeks because it's talking about a different set of images, from January. The uncompressed images from the fly-by will take the roughly 16 months you mentioned, but there will be smaller, compressed images before that.

I think it's 16 months to transfer every piece of sensor and imaging data back. The article says it takes ~40 minutes to transfer back a losslessly compressed full resolution image from the LORRI scanner

One of the early things I did when I obtained a computer modem was dial into a NASA BBS and download images of planets taken by Voyager. I believe it was at 300bps, although we may have had our 2400bps modem by then.

Fortunately I didn't spend 16 months at it, since we were paying long distance charges and just a couple of pictures of Neptune downloaded over the course of an hour or so cost a relatively ridiculous amount of money.

Still, it makes me feel a kinship with these folks, even if just barely.

Anyone got info on the software/hardware specs and how they approach prioritizing and storage management? We waited a long time for the Apollo code to make it to Github--what better way to rope in the interest of one segment of humanity than getting more eyes on the code?

I imagine that there wasn't time or power to do patches...but if there was, even the mechanics of that would be fascinating.

Has anyone ran across a good discussion around the computational aspects of New Horizons?

http://www.planetary.org/blogs/emily-lakdawalla/2015/0624055...

http://www.planetary.org/blogs/emily-lakdawalla/2015/0130080...

Some basic info on communication. The wikipedia page has a lot of info.

The most important parts are that it has a redundant pair of 8GB flash drives and they actually upgraded the code in-flight to use both transmitters at once and nearly double the data rate.

I'm not sure how priorities are arranged but it's all going to be sent back relatively quickly in terms of mission lifetime, and I think they managed storage use mostly by putting in plenty.

they actually upgraded the code in-flight to use both transmitters at once and nearly double the data rate

It was anticipated this would be possible, depending on how the energy budget for the whole craft worked out.

That's the delay in getting a single batch of images back during the approach phase, not how long it'll take to get all of the images from the flyby back.

Reminds me of RealPlayer.

Also "planet"!?

Direct link to image gallery: http://www.nasa.gov/mission_pages/newhorizons/images/index.h...

Considering the context (the significance of this event to the entirety of humanity), is this sort of nationalism gross to anyone other than me?

http://www.nasa.gov/mission_pages/newhorizons/images/index.h...

Meh. You're cherry-picking one photo from that slideshow.

Yes; we could be a little more inclusive and magnanimous; it's an achievement for humanity (or does the U.S. get Pluto now?). I tend to suspect everything we see from NASA is choreographed; this might sell funding to part of NASA's tax base.

Europe is larger than the US and should be able to compete but can't for some reason.

What is even more interesting, the artist Don Dixon more or less accurately predicted how Pluto looks like in 1979.

Very interesting!

Direct link: http://www.cosmographica.com/spaceart/pluto-predicted.html

Well, his painting shares some superficial features that look similar to that one photo. Like a similar overall shading from light to dark. Other photos of Pluto look nothing like Dixon's painting. The "Pluto with a Heart" pic, for example.

Dixon's painting is cool, but let's not make it something it's not.

Let's also remember the fallacy of multiple endpoints. Many artists have rendered visual guesses at what Pluto might look like. And many will be totally wrong. We're cherry-picking the best example in Dixon, not a typical one.

Great point (love the fallacy of multiple endpoints).

But there also may be some "algorithmic" smarts here in terms of Dixon's interpolation/extrapolation of what cold planetary bodies look like, even with what was known in 1979. Think of an image-generator bot that took some parameters of what was known (distance from Sun, whether it was a gas planet, atmospheric conditions, position relative to the asteroid belt, how size affects features) and kicked out plausible planets. This might be close to what you'd come up with if you made the mistake of forecasting more meteoric impact than actually occurred.

The Pluto photo he's using doesn't look like Pluto from NASA's website...

The estimate that this area is very new based on the fact that there are no meteor craters assumes that we know the distribution of meteors and space debris in the outer solar system. Does anyone know if we do in fact know this?

It seems plausible that there would be far fewer things at that distance, so the frequency of collisions would be lower.

They determine what they expect on Pluto by looking at the most cratered parts of Pluto. It is model-dependent. There are other assumptions involved, such as the distribution of crater sizes.

I believe that NASA expected lots of craters on Pluto due to its close proximity to the Kuiper Belt, which is full of asteroids and other small objects.

https://en.wikipedia.org/wiki/Kuiper_belt

Full is quite relative. The Kuiper belt encompasses a ridiculously large volume of space.

Similarly, the asteroid belt is "full of asteroids" that are mostly only a few meters across, with an average distance between each asteroid of a few million kilometers.

how does Pluto's inclined orbit (https://en.wikipedia.org/wiki/File:Plutoorbit1.5sideview.gif) affect its exposure to other Kuiper Belt objects? Is it still well within the cloud of objects at its greatest points of divergence from the ecliptic?

I wonder:

1. If it is reasonable to expect fewer collisions over time, as earlier collisions eject some objects from the belt and remaining objects settle into "safer" orbits?

2. Whether collisions cause objects to break apart such that subsequent collisions are with smaller objects, which then leave fewer discernible impacts?

3. Whether the temperature changes induced by Pluto's orbit--which cause the methane ice to move between the atmosphere and the surface--would cause a smoothing effect over time; e.g. craters being filled by reforming ice?

It also seems plausible that there would be more collisions that far out - Pluto is believed to be a Kuiper Belt object, after all.

Emily Lakdawalla's commentary:

http://www.planetary.org/blogs/emily-lakdawalla/2015/0715172...

I don't use "mind blown" too often, but I will in this case. Here I am, sitting on my ass munching on a snack, admiring the mountains of a planet 3 Billion miles away. This is so amazing.

I'm desperately trying to view the images on a shoddy Italian hotel Wifi and can't help thinking how ironic it is that the images were sent six bazillion km from the edge of the solar system but I can't beam them the last ten meters. Rocket science!

Technically you just should give it 4 and half hours. I’m pretty sure digital divide here in Italy is not THAT powerful!

*dwarf planet

  class Planet {}
  class DwarfPlanet : Planet {}
  // ...
  var pluto = new DwarfPlanet();
  Console.WriteLine(pluto is Planet);

Plutino!

https://en.wikipedia.org/wiki/Plutino

https://www.nasa.gov/sites/default/files/thumbnails/image/pl...

This is a time-lapse series of images of Pluto over the years - from a couple of pixels to today's mountain ranges. In about three seconds you get a full, visual, easy to read justification and explanation for the whole space budget and science funding - it is awesome.

This is what we want to see - go NASA

I am always amazed at how far we've come. I wish I could live 100 years more.

I completely agree. I keep saying that nothing interesting happens in less than 10,000 years. Or a million. Compared to the Universe, human lifetimes are instantaneous. Such a pity.

Next century's hottest snowboarding destination...

At 44K (-380 F), I'd say it's more like next century's coldest snowboarding destination

But at least the lifts won't be windy.

Except there is an atmosphere...

I’m very sorry to inform you that at those temperatures you’d be frozen to death. But even once you came out with some cool (hot?) solution for this nicety, you still couldn’t ski/snowboard. That’s because the snow on earth is relatively close to 0°C, and therefore in that particular stage where ice is lighter (it has more volume) than liquid water. If you apply pressure to it it’s easier for the ice to go back to the liquid state and therefore giving you the ability to ski.

At those temperatures it would be as snowboarding on sand. Which is a very loved sport, but not that easy.

The sandiness of the snow might not be much an issue in Pluto's low gravity. It would be a bit like skiing on tiny marbles, but with lots of time to recover your balance. He won't be setting any landspeed records, though.

The real problem is getting there and back in time for the end of your two week vacation.

Didn’t thought of it!

Let’s solve that timing issue!

I think the snow they're discussing consists of frozen nitrogen, but you're right that the nitrogen phase diagram is not as interesting as that of water at habitable temperatures and pressures.

I was under the impression that snowboarding did not reach very high pressures. Does it actually liquefy the water? I thought it just mattered that the snow was 'relatively' lightly packed for purposes of absorbing shock.

AFAIK the fact that you see the snow getting shiner and smoother once you pass on it skiing comes from the fast liquefaction and solidification happening.

The jumps would be pretty radical for sure.

don't forget your torch!

I did not really know what to expect but these photos are amazing and they're not even from the nearest approach!

Who knew the surface would be so crater free?

I have seen a number of articles about the lack of craters and the assumption that this means recent geological activity. But that would assume a similar craterization rate to that of the inner planets like Mars and our Moon. I am wondering, is it possible that due to it's orbit, distance and smaller size that the rate is just a lot slower?

whatever, It is just a mind boggling accomplishment, and the photos really are incredible.

Also a cool shot of Hydra, for the first time showing its shape.

https://www.nasa.gov/image-feature/hydra-emerges-from-the-sh...

It's very surprising to me how much (apparent) recent geologic activity there is on both pluto and charon. I had expected them to be much more mercury like.

Pluto was my favorite planet growing up. I never dreamed I'd get to see it up close.

I can't help it. I tear up and I get all emotional every time I see NASA pictures of a new planetary surface.

To think a bunch of apes can look at and appreciate mountains 6 billion kilometers away... it's awe inspiring!

Nobody has seen those mountains before!

I can understand why people like my wife look at these pictures and say, "Meh. That's nice."

The enormity of the distances and what humanity has done is, quite honestly, beyond what our minds are actually capable of fully comprehending.

I'll re-post this for your weekend enjoyment:

http://joshworth.com/dev/pixelspace/pixelspace_solarsystem.h...

Amazing. Crater-less mountains, and we have no idea how they were formed (or are forming!). Lots of exciting science ahead!

Having to come up with scientific lessons on the spot ("this may cause us to rethink..."), for the sake of press releases must be pretty stressful. I'm also not sure that such more-or-less impromptu analyses foster the right conception of how science works.

Well, per Emily Lakdawalla's blog quoting scientist Amy Barr (http://www.planetary.org/blogs/emily-lakdawalla/2015/0715172...):

Every time we have looked at a body that has experienced tidal heating, such as Io, Europa, Enceladus, we find that the body has been more active, or is putting out 10 to 100 times the amount of heat predicted by models.

Enceladus taught us that our models of tidal heating for icy bodies were not right, and I think the Pluto/Charon system could be telling us something similar.

And it's not like these people weren't already reviewing the current state of the art in anticipation of how these Pluto images might add to it.

How do they measure altitude of the mountains without a sea level?

It's based on the mean surface level rather than the mean sea level.

This made me wonder, how do they measure the heights of the mountains? Using data from multiple view angles?

Why are most of the pics black and white?

See here: http://www.planetary.org/blogs/emily-lakdawalla/2015/0310163...

New Horizons is able to transmit to Earth at only about 2 kb/s (I might be slightly off). So right now, and for about the next week it will be sending back essentially thumbnail images (in addition to science data). These are JPEG-compressed, and during this stage will only be from the panchromatic (b&w) camera, which has a higher resolution. Later this year it will begin downlinking the full set of uncompressed, full-resolution images, including those in color. The full dataset is expected to be about 60 GB and will take about 18 months to downlink.

The camera is monochrome, another sensor gets "color" information. I think even the black and white images are not really "true" images since the sun is really really really far away (not totally sure about that though).

EDIT: LORRIs images are true, Pluto is actually pretty bright (the sun is amazing) and the camera is great (science is a amazing).

On Pluto, the Sun is 250x more bright than the moon is on Earth. And moonlight (at a full moon) is pretty sufficient for most things you do with your eyes.

http://blogs.discovermagazine.com/badastronomy/2012/03/15/ba...

That's because the human eye works across an amazing range of light intensities. https://en.m.wikipedia.org/wiki/Adaptation_(eye)#Efficiency:

"The human eye can function from very dark to very bright levels of light; its sensing capabilities reach across nine orders of magnitude. This means that the brightest and the darkest light signal that the eye can sense are a factor of roughly 1,000,000,000 apart. However, in any given moment of time, the eye can only sense a contrast ratio of one thousand. What enables the wider reach is that the eye adapts its definition of what is black."

Pluto is 30-50 AUs from the sun, so ignoring the effects of any atmosphere, there's "only" a factor of 900-2500 more sunlight on Earth than on Pluto (sun vs full moon is 400,000:1 or thereabouts)

Yeah, I was surprised about how bright the sun is on Pluto. Before this week, I thought that it was pretty much just starlight on Pluto with the sun looking more like Venus at night.

It turns out that the day on Pluto is like dusk on Earth. Check out this great page from NASA: it will tell you the time (for your location) where the daylight will be equivalent to the daylight on Pluto: http://solarsystem.nasa.gov/plutotime/

You can also see photos other people have uploaded, giving an idea of what Pluto daylight looks like. Surprising bright.

For me, it's something like 8:15pm when the daylight is equivalent to Pluto.

It can't actually take 'true' colour pictures at all --- RALPH has sensors in blue, red, infrared and methane, but not green.

I suspect they can probably synthesise true colour-ish by comparing the monochrome images to the blue and red ones; subtract blue and red from overall brightness, and what you have left is green (ish).

Enormously technical nigh-incomprehensible paper here: http://www.boulder.swri.edu/pkb/ssr/ssr-ralph.pdf

The highest resolution imaging system, LORRI, is monochrome. They can provide color by using another, lower resolution system named Ralph, or by any of a number of false color approaches. See more e.g. here: http://pluto.jhuapl.edu/Mission/Spacecraft/Payload.php

Honestly speaking, "colour" cameras we use every day are also false colour; they shoot 3 monochrome images in red, blue and green chunks of spectrum and mix the whole thing using plethora of parameters like white balance, or gamma. All this is heavily tuned towards human vision specifics to enable either monitor or print to induce a similar sensation in the viewer's brain that the photographed object would, despite the fact that the whole process retains only a negligible fraction of the information carried into the camera by the original photons. Quite a lot of animals perceive the hue of human-made photos and videos as totally odd, misexposed or desaturated, just because of having vision adapted to wavelengths or other properties of light which our processing mostly removes as redundant. Even more, one day humans may start to enrich their vision by technological or biological modifications, consequently beginning to perceive today photos as as dull as we see those old, monochrome ones.

To elaborate a bit, almost all digital cameras take a single monochrome exposure but each sensor element has either a red, green, or blue filter over it, in a mosaic pattern. From the relative brightnesses of neighboring pixels color data can be reconstructed and interpolated to form a human-viewable image.

The Foveon sensors are a sort-of exception to this rule, but they haven't really demonstrated enough visible benefits for them to become widely adopted.

That's how you get the highest resolution possible, all else being the same. Instead of having sensors for different light wavelengths, you just pack more of them.

If they had a bigger probe, they could have used color filters to take 3 pictures and then combine the resulting images into a single one with color information. Size and complexity constraints probably prevented that.

They have color filters. In fact the biggest single pictures are taken using the color camera.... in black and white mode.

The main limitation is time. They're blowing through in a couple hours. Monochrome data is faster data.

Because the instruments that took the pictures monochrome.

Url changed from http://www.bbc.com/news/science-environment-33543383, which is a fine article that adds some info, but perhaps not enough to override the preference for original sources.

Thanks. The audio piece by John Spencer in this article is well worth listening to.

Thanks – I really like to see NASA.gov all over the homepage.

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