APOD: Crossing Mars (2016 May 02)

[APODFORIST]

This business of "extending" missions is absurd. The policy should be that a mission lasts as long as the spacecraft is functional.

That's simply not possible. Projects operate under budgets, and there's no way the system will work with open-ended budgets. Projects have goals and timelines. Once those are met, if the equipment can still support it an extension can be proposed and budgeted, just like any other project.

It's not like this mission is free now that the launch and rover have been paid for. The tens of millions of dollars a year it takes to run it have to come from somewhere.

But Opportunity is now driving around Mars for 12 years. I am pretty sure they will not shut down it - or Curiosity - until the rovers get out of order (as Spirit). Wouldn't it be crazy to let a working and healthy Mars rover alone after landed it there safe?

[BMAONE23]

funny thing is, in the linked article the Dress is clearly either Light blue/Gold or White/Gold with Blueness caused by shadowing while the adjoining article definitely is Royal Blue and Black
The WIKI article definitely displays a dress that is not Blue and Black

https://www.buzzfeed.com/claudiakoerner ... .qp5ZR1l4R ...... https://en.wikipedia.org/wiki/The_dress ... henomenon)

And the one she wore is also definitely Royal Blue/Black

[geckzilla]

I think these photos are closer to reality than whatever you're imagining.

I agree. Images almost never capture what things actually look like. Our eyes automatically color balance everything to a sunlit-Earth norm. Images generally don't. The reference targets on the rover are neutral, which tells me this image has had its white balance set about right, and that means that what we're seeing here is probably pretty close to the visual appearance we'd get standing on Mars.

Isn't that taking the idea of automated white balance in the brain a bit too far? A cloudy day on earth is grey, a sandstorm makes the sky appear yellow-reddish-brown on earth, so why should we expect the dusty sky on mars to look blue to us?

Because Mars is a dynamic place and your assumptions about what its sky is like aren't necessarily correct. There are clearer days, dustier days, and the sun moves around as the planet rotates. Different conditions result in different colors in the sky, just like here on Earth. The point here is that the sky hasn't had its color changed. It's been processed and the contrast and color balance has been *tweaked* but it's absolutely nothing different from the tweaks photographers do to their work here on Earth and nobody calls them out on it because it still looks just as real. The point is, the photo wasn't balanced to make the sky blue, it was white balanced to balance the colors of the entire image. Have you ever taken a photo with a DSLR and looked at the RAW data?

Here's something else for you to think about: Curiosity's detectors aren't as sensitive to blue light as a human's eyes are.

Anyone wishing to view unprocessed images from this panorama can go here and from the top menu change "Sol" to 1302
http://curiosityrover.com/

[PrivateWiddle]

I think these photos are closer to reality than whatever you're imagining.

I agree. Images almost never capture what things actually look like. Our eyes automatically color balance everything to a sunlit-Earth norm. Images generally don't. The reference targets on the rover are neutral, which tells me this image has had its white balance set about right, and that means that what we're seeing here is probably pretty close to the visual appearance we'd get standing on Mars.

I thought our brains did the colour balancing, not our eyes?

[Chris Peterson]

I think these photos are closer to reality than whatever you're imagining.

I agree. Images almost never capture what things actually look like. Our eyes automatically color balance everything to a sunlit-Earth norm. Images generally don't. The reference targets on the rover are neutral, which tells me this image has had its white balance set about right, and that means that what we're seeing here is probably pretty close to the visual appearance we'd get standing on Mars.

Isn't that taking the idea of automated white balance in the brain a bit too far? A cloudy day on earth is grey, a sandstorm makes the sky appear yellow-reddish-brown on earth, so why should we expect the dusty sky on mars to look blue to us?

No, I don't think it's taking things too far.

I'm not suggesting that our color balance system makes the sky seem blue if it's not. What it does is make white things look white (or neutral) even if they aren't illuminated by white light. The martian sky can be blue, just as it can be reddish. It depends on the position of the Sun and the dust content of the air. The fact that the color has been reasonably balanced for the neutral targets suggests that the overall color balance is reasonable. It's entirely possible that the sky actually is blue in this image. At the least, even if the sky is not quite right, the total illumination- Sun plus skylight- has been balanced correctly which means the landscape is well represented, which is much more important that getting the sky right.

[Chris Peterson]

I think these photos are closer to reality than whatever you're imagining.

I agree. Images almost never capture what things actually look like. Our eyes automatically color balance everything to a sunlit-Earth norm. Images generally don't. The reference targets on the rover are neutral, which tells me this image has had its white balance set about right, and that means that what we're seeing here is probably pretty close to the visual appearance we'd get standing on Mars.

I thought our brains did the colour balancing, not our eyes?

They're both involved. I just used "eyes" here as a shortcut for the whole system.

[Chris Peterson]

NASA has a limited budget. Decisions on ending missions have to be made, or new and better missions will be delayed, with the effect of less total science. This is called Management 101.

It costs millions a year to run existing missions, billions to launch new ones. Closing down existing missions to add pennies to a new mission's budget is the very definition of "penny wise, pound foolish."

It depends on the mission. In many cases, the operating costs can exceed the development and launch costs.

How many missions are you aware of that were returning solid science and were shut down at the end of their funding cycle despite everything still working well? That's not common. Usually, missions that are successful are extended. That's a much smarter way of operating than simply saying the length of the mission will be dictated by how long the equipment lasts. Older missions need to justify their existence periodically. Even if the equipment works, it might not make sense to keep operating.

[Ann]

Geck wrote:
The closer we look to it, the bluer the sky appears, exactly as previously celebrated: "Mars has blue sunsets! Holy crap!" (For some reason nobody questioned that when it went up on APOD.)

Maybe that's because Mars has blue sunsets, unlike the Earth. It's just the daylight sky Martian sky that isn't blue, or at least I don't think it is. I can remember my own shock when those first Mars landers (what were they called, Vikings?) compared the Martian sky with the color samples they had brought with them and sent home the stark message, the Martian daylight sky isn't blue, but rust-colored!!!

But really, I know what you mean by human vision adapting to ambient light to produce a neutral color vision. I still think it is okay to try to show how "absolute" color on other worlds would look like, because I think that there is such a thing. I still remember my fascination at an illustration of the daylight at a planet orbiting a red dwarf of spectral class M. The daylight sky on this planet was quite dark, because an atmosphere like our own would not scatter yellow and red light very much. Imagine that, a dark daylight sky and a deep-yellow sun mostly surrounded by darkness in the sky. I don't know if the assumptions behind an illustration like that have any bearings on reality, but I'll never forget the picture.

But hey... I searched the web for some more info on the color of the daylight sky of Mars and came across something that smelled like conspiracy pages to me. I'll have nothing to do with sites like that.

Ann

[geckzilla]

But hey... I searched the web for some more info on the color of the daylight sky of Mars and came across something that smelled like conspiracy pages to me. I'll have nothing to do with sites like that.

Yes, unfortunately the topic of Mars is rife with rusty Martian excrement. Mars may not look exactly to you like it does in these photos, but it's still the best approximation we have and photographic data will always be more accurate than our memory. I do not find it hard to believe that some days on Mars may have darker, less overcast skies and that those darker skies would be tinged ever-so-slightly blue due to the very fine particles in the sky. On a day dominated by larger particles stirred up from the surface, the sky might appear a kind of bright white, perhaps slightly off-white, barely discernible cream color. Nature will always defy our biases, even if we refuse to concede in the face of contradictory evidence.

[Guest]

When I first read the reports from Phoenix, I was excited. Water on Mars. Then it became clear. This water was, at least, three billion years old and was so salty it could be used to kill bacteria on a urinal in a New York toilet. Keep looking NASA. We need proof.

[Mary, the Mars pro]

Of course the sky is blue on Mars, it was made 'pale ochre' in the 20th century so that the plebes on Earth would think the planet is uninhabitable.

[rstevenson]

Of course the sky is blue on Mars, it was made 'pale ochre' in the 20th century so that the plebes on Earth would think the planet is uninhabitable.

Rob

[Ridgeview Astronomy]

Why is the sky blue in this image, instead of orange/red?

[geckzilla]

Rayleigh scattering

[Fred the Cat]

Why is the sky blue in this image, instead of orange/red?

Here's one site that answers the question for both planets.

[enemy]

Sorry! What is the strange white structure at photo right/up corner? Its look like some mechanical think...

[Ann]

Why, it's a white Madonna statue and behind it is a specimen of the Martian dog (Canis Martius), running away after it was unsuccessfully trying to snatch the baby away from Our Martian Lady. Or...wait, it is Elvis in his white jumpsuit!

Perhaps I shouldn't joke about this... maybe someone is taking it seriously?

Ann

[geckzilla]

I'm gonna take a guess, here. Rocks. They're rocks, right?

[enemy]

Rocks, stones, crust of dirt. Simply. But ящщь original photo and see there where at It martian dog Aibo leg - shade falls correctly.

[enemy]

Sorry! But zoom original photo... (Automatic translation tricks into)

[rstevenson]

Sorry! But zoom original photo... (Automatic translation tricks into)

I've zoomed the original photo and can't even find that bit of hill top. Are you sure you're looking at the same photo? Please give the URL of the image you are seeing.

Rob

[enemy]

http://apod.nasa.gov/apod/image/1605/Ma ... y_8703.jpg
Here in the left/overhead corner...
White каменьв the first inch of image.

[rstevenson]

Oaky, that's the image I was looking at. You said it was in the right corner. Now I see it top-left.

Here's a 500% zoom on that rock...

With pixels as big as that the human brain can see almost anything there. But I agree with Geck's guess, it is a rock. A pale coloured rock and therefore perhaps worth exploring, but just a rock.

Rob

[enemy]

Yes! My error. Found a photo on the кussian-language news web-site. Inverted. Found a meter line. inverted. and wrote wrong...

Certainly. I think too, that it is a stone or row of wreckages of siltages. But it would be interesting to look nearer. It is sorry that research missions. still roads and limit in resources, for the side opening.

[rstevenson]

One of the things I find most frustrating about seeing all these images from our amazing rovers is that there is no human there to say, "Hmmm, that looks interesting. Let's have a look." Sure, the rover team does some of that, but it's a major job to get the rover to go over there to have a look, where a human could just jog over and give it a poke, take a close-up photo and maybe a sample, and be back in 10 minutes. We need to start getting people there ASAP, trained scientist/explorers at first, of course.

Rob