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NASA's Perseverance rover sends stunning images

bbc.com

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Re: NASA's Perseverance rover sends stunning images

#111

Post by khuey »

matheusmoreira wrote: post #109
khuey wrote: post #81

Earlier quoted context omitted.

The radiation emitted by plutonium 238, which is what's found inside RTGs, is easily shielded by essentially any solid material. The real reason you don't want an RTG powering your fridge is that it costs on the order of one million dollars per watt.

> easily shielded by essentially any solid material If that shield fails for any reason, including tampering, you're looking at the radiological contamination and likely deaths of everyone nearby at the very least.

Alpha sources outside the human body are of little health concern. You'd have to break it open and eat the plutonium inside for it to be a serious risk.

Re: NASA's Perseverance rover sends stunning images

#112

Post by phonethrowaway »

gtm1260 wrote: post #87

Stupid question maybe but like is there a reason the picture quality seems worse than a decent dslr photo? I'm so curious what that photo would look like, taken with an everyday camera, without the bizarre 'scientific' look of these shots.

speculation, but it's probably compressed before transmission to earth... for obvious reasons.

Re: NASA's Perseverance rover sends stunning images

#113

Post by Balgair »

gtm1260 wrote: post #87

Stupid question maybe but like is there a reason the picture quality seems worse than a decent dslr photo? I'm so curious what that photo would look like, taken with an everyday camera, without the bizarre 'scientific' look of these shots.

Generally, these cameras are many years out of date. They don't load up the rovers with the latest gear from today, but with the latest gear from when the design review process was closed. I don't know when that was for Perseverance, but it would not surprise me if that was a decade ago. The cameras are also not specifically designed for image capture, but for scientific study. In that they take images at a wider range of wavelengths than what humans can see. It's a subtle difference, but an important one. Additionally, the cameras' chips are not what we have commercially. They are designed to withstand the vacuum, the solar radiation on the long transit, and for use on the Martian surface for many years. You can't swap them out, ever. As such, they are much more 'rugged', which may effect image quality as well.

Re: NASA's Perseverance rover sends stunning images

#115

Post by rtkwe »

nitrogen wrote: post #74
AnimalMuppet wrote: post #54

Earlier quoted context omitted.

What's powering Voyager is a plutonium pile. Pretty sure you don't want that in your fridge. 10 billion miles from me? Sure, knock yourself out. 10 feet from me? No way.

AKA "Not In My Back Yard." So the question stands and extends to include this: "why not?"

There's a lot of waste heat put out by RTG. The one powering Perseverance has an output of about 110W but thermocouples have about 5% efficiency so there's ~1900W of heat you have to deal with. For a fridge the running power can be almost double that it's just completely silly on Earth except for odd places like the lighthouses along Russia's northern coast where there was no way to get a grid connection, not enough sun for solar, and suppling diesel constantly was impractical.

Re: NASA's Perseverance rover sends stunning images

#116

Post by ryandrake »

justinator wrote: post #101
mzg wrote: post #73

Earlier quoted context omitted.

Not sure about you, but I was promised fusion-powered DeLoreans by now.

You don’t have the Mr. Fusion upgrade? Run that sucker on trash. Had it since 2015.

I was promised that by at least 1985, plutonium would be available in every corner drugstore.

Re: NASA's Perseverance rover sends stunning images

#117

Post by 29athrowaway »

snicker7 wrote: post #38

Any good desktop wallpapers out of this?

Curiosity took pretty nice pictures that you can very easily turn into wallpapers.

https://mars.nasa.gov/resources/curiositys-1-8-billion-pixel...

Take the second one from that page, for instance, zoom in, and just take a screenshot and use it as your wallpaper.

Re: NASA's Perseverance rover sends stunning images

#118

Post by evilos »

medium_burrito wrote: post #67
evilos wrote: post #57

Earlier quoted context omitted.

Surviving rifle fire has been a solved problem since like, the bronze age. Add more metal. Getting to and landing on another planet (intact and functional) on the other hand, is probably like 3 orders of magnitude higher in difficulty.

Inquiring minds would love to know about a practical solution. You can add more material, but that's extra bulk and weight. I think we can agree that a mountain is bullet proof, but that's not really practical. Also, rifles are really good at shooting through shit. We're talking rifles from 1890s. People don't realize that a bullet from a rifle punches through steel plate (and then buy steel body armour like the pleb…

Not really sure how this relates, but ok.

The vast majority of combat causalities are from explosive fragmentation anyways.

Re: NASA's Perseverance rover sends stunning images

#119

Post by CharlesW »

suyash wrote: post #114

Can someone explain, is this how Mars would look to us with naked eye or this is an artistic/digital interpretation?

My understanding is that these are how they'd look with the naked eye. There's a color calibration target on the rover.

https://mars.nasa.gov/resources/25619/mastcam-z-looks-at-its...

Re: NASA's Perseverance rover sends stunning images

#120

Post by Trasmatta »

idiocrat wrote: post #17

All the extraterrestrial expansion, dream of Men to conquer Space, star track enterprise! I'm pessimistic that we will ever leave our solar system, and if so in 1000 years, I do not care. Hopefully people learn how tiny our bubble is and protect our environment more. The Martian environment looks so boring -- as a replacement for polluted Earth. (We will pollute Mars faster than Earth). I'm living at the ocean, tryin…

> We will pollute Mars faster than Earth

I don't see how this is possible. At most, Mars might have small, organized colonies someday. Earth has billions of people.

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