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Welcome to a comet

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71–80 of 87 posts

Re: Welcome to a comet

#71
post #4

Also very interesting, if you look at the high-res picture and zoom at the bottom right, you'll notice some sort of cable on the ground/boulder. This could be the cable from one of the harpoons that may have fired but didn't anchor themselves, or it could be a feature attached to Philae that's in the field of vision.

That's one of the audio cables from the sound stage. If you look closely you can see the shadow of a boom mic on one of the rocks.

My first thought was: "Why would they need a mic? There's no sound in space" and then I felt the whoosh over my head. Well done.

Re: Welcome to a comet

#72

Possibly stupid question: why are all the images greyscale? Could we not send a color camera? Or is the comet very grey? Or does color not work in space?

color works just fine

I know that sometimes, images are first sent in black and white to save on data, color is sent later.

Hubble apparently only does black and white. color images can be obtained using a technique involving two of its black and white images. But that is a telescope, probably not similar.

http://hubblesite.org/gallery/behind_the_pictures/meaning_of...

the comet could just be grey, not sure about that one.

Re: Welcome to a comet

#73
post #26

So "Armageddon" was right. A comet looks much more interesting than the Moon or Mars. No boring dunes and flat sands, really rocky.

I'd say this is a far-cry from that dramatization, but hey, they weren't as far off as we thought!

Comet 67P seems a lot more rugged than previous comets we've been to.

Re: Welcome to a comet

#74

Possibly stupid question: why are all the images greyscale? Could we not send a color camera? Or is the comet very grey? Or does color not work in space?

color works just fine I know that sometimes, images are first sent in black and white to save on data, color is sent later. Hubble apparently only does black and white. color images can be obtained using a technique involving two of its black and white images. But that is a telescope, probably not similar. http://hubblesite.org/gallery/behind_the_pictures/meaning_of... the comet could just be grey, not sure about tha…

Also, cameras are much more sensitive and higher resolution if they are B&W. A colour camera has to have a bayer matrix filter in front of the pixels (or some other weird trick) which throws away a load of the light.

Generally, when telescopes want colour images, they will take several pictures with different filters in front of the telescope, then combine them. This is useful because you can have a wide selection of filters, including ones for specific science-related wavelengths, like hydrogen alpha, or oxygen emissions. A normal colour camera is limited to three filters.

Re: Welcome to a comet

#75
post #44
post #42

Earlier quoted context omitted.

Even if it is so (and we can talk for hours on the validity of this or that data) how do you find the fact that there are enough damned means of production to feed everyone and it's been so for decades now? Also how do you like the fact that there are now about 50-60 MILLION people in US that get food stamps. Or the fact that the wages for most of the western world are falling for 30 years now? ... Whatever.

Before we cut space missions, can we please stop paying so much for warfare and spam first?

> can we please stop paying so much for warfare

an awful lot of research for space has been done with defense budgets

Re: Welcome to a comet

#76
post #31

From Reddit[1]: "Got fresh news from the team, they are broadcasting live right now on french TV ! Philae landed, and bounced slowly for (1-2-? hours), and travelled 1km away the targetted site. Yes 1000m. Then know this because of the datas from the radar. It's now stopped slanted, some cams are shooting the sky, other the ground, and other nearby rocks, as seen on the first photo. It's inside some kind of cave/hole…

The full panorama is available: http://www.esa.int/spaceinimages/Images/2014/11/Comet_panora...

Re: Welcome to a comet

#77

Possibly stupid question: why are all the images greyscale? Could we not send a color camera? Or is the comet very grey? Or does color not work in space?

The comet is in fact very very black, but pretty much all cameras are greyscale. Most 'colour' cameras are just a series of filters placed over the pixels to sense only light of the desired colour (usually RGB)

When science has to be done, it's easier to have a selectable set of filters you can put in front of the whole sensor at once. This way you can use the full sensor resolution and you can have a wider variety of filters. They also tend to bring along spectrometers of some description which are again much much more useful.

Re: Welcome to a comet

#78
post #16

You know I have some bad days some times, but seeing shit like this just makes me think "What a fucking time to be alive!" It's truly incredibly and is sometimes that kick in the pants I need to keep on going. We are living in a golden age of humanity right now, at no point before in human history have so many people had such an incredible quality of life and never before has man been doing such incredible feats and…

Yes it is golden age as long as you disregard percentages and trend. "Some 805 million people in the world do not have enough food to lead a healthy active life. That's about one in nine people on earth." http://www.wfp.org/hunger/stats Economy seems like a boiler ready to explode, rich-poor chasm is widening like hell. Global peace doesn't look very rosy either. Not to mention what's happening on the environmental f…

Every age has its little people whose entire contribution to public discourse is to complain about how dreadful everything is. They add nothing good to the world. They don't feed the hungry or clothe the homeless the way creative people operating within the framework of capitalism, the rule of law and global trade have been doing for the past several hundred years. They just complain about how awful everything is.

I'm not sure why they consider this a worthwhile thing. Clearly they are capable of identifying problems, but aren't capable of doing anything about them. As such, they should get out the way of the people who are actually solving them. A hundred years ago such people were complaining that capitalism and global trade were evil and destructive, and they and their fellow-travelers attempted several more-or-less violent approaches to overthrowing them, which held back human development by decades and destroyed tens of millions of lives.

Despite those abject failures, the same anti-empirical wingnuts are back today, when capitalism, the rule of law and global trade have created an era of unprecedented peace and prosperity--exactly as their irrational predecessors predicted would never and could never happen. But they don't let anything so Enlightened as mere empirical reality prevent them from continuing their litany of complaint and opposition to progress.

Re: Welcome to a comet

#79
post #16

Earlier quoted context omitted.

Yes it is golden age as long as you disregard percentages and trend. "Some 805 million people in the world do not have enough food to lead a healthy active life. That's about one in nine people on earth." http://www.wfp.org/hunger/stats Economy seems like a boiler ready to explode, rich-poor chasm is widening like hell. Global peace doesn't look very rosy either. Not to mention what's happening on the environmental f…

Every age has its little people whose entire contribution to public discourse is to complain about how dreadful everything is. They add nothing good to the world. They don't feed the hungry or clothe the homeless the way creative people operating within the framework of capitalism, the rule of law and global trade have been doing for the past several hundred years. They just complain about how awful everything is. I'…

Seems some people complain as a survival strategy: enough whining will persuade others to resolve problems & supply needs, if only to shut that person up.

Re: Welcome to a comet

#80

It almost seems like "landing" is too strong a word: Philae has a mass of 100kg and the gravity of Churyumov–Gerasimenko is estimated to be 10e−3 m/s2, which comes out to a weight of 3.5 ounces, or the equivalent of 100 grams on earth. Let's hope it holds!

Thanks to the sorta dumbbell shape, depending on where Philae landed the apparent gravity may be a LOT less, should a considerable amount of the comet's mass be "above" the lander. (Think "what's the pull of gravity in the center of a planet?")
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