The spiral galaxy of Galaxy NG1300 lies 70 million lightyears away from Earth on the Eridanus constellation. Its one of the largest photos ever made by the Hubble telescope.

This one might possibly be my favorite so far.

I've found and looked at NGC1300, its a good sprial galaxy, which you can see clearly.

Centaurus A, the closest galaxy towards our own on a distance of 60000 lightyears.

It's a further away that 60k light years Andromeda is the closest galaxy (2.6mill light years) although there are dwarf-galaxies like the Large Magellenic Cloud which is 160k ly away.

Way too far to drive. ;D

not sure if this has been posted but if not really cool

A timelapse of Planet Earth from Electro-L, a geostationary satellite orbiting 40000km above the Earth. The satellite creates a 121 megapixel image every 30 minutes with four visible and infrared light wavelengths. The infrared light appears orange in these images, and shows vegetation. The images were obtained beginning on May 14th, 2011 and end on May 20th. The images are the largest whole disk images of our planet, the resolution is 1 kilometer per pixel. The images are "masked" by a circular barrier that blocks out the light of the Sun and other stars. This is to prevent damage to the camera by exposure to direct sunlight. The images have been interpolated (blended) to create a smooth animation.

Thanks JSG.. videos like these are exactly what intrigues me about space. You have the Earth and then theres literally nothing, just "space". An enormous amount of black, an amount of "nothingness" and it is frightening and extremely interesting.

Just been scouring out some info about the satellite itself.

It is from the Elektro Geostationary Hydrometeorological satellite family, a Russian satellite. It's the Elektro L N1, it's stationed directly above the Indian ocean, and has an image periodicity of 30 minutes usually, but can be reduced to 15 minutes. The resolution of the images is down to 1km in the visible spectrum and 4km in the IR spectrum. The satellite will operate for another ten years, and there are the Elektro L N2, and N3 satellites situated in the East Atlantic and West Pacific oceans.

saw the word Elektro and wondered if it was an Ion Thruster engine. but apparently not. I know the Russians did use them a fair amount

The sort i worked on looked like this



however the part i worked on was only the Hollow Cathode part where the ions are generated.

So what's the Potential difference that you usually used to create sufficient ionisation of the plasma (possibly a noble gas?), or requisite emission of cathode rays, for the propulsion. I'm a slight bit of a dunce on such issues.

And if the ion beams get neutralised during exhaust (if I'm seeing the figure correctly), does that mean there's a method of re-harnessing the exhaust?

they do not re-harness the exhaust and they generally use xenon and sometimes Argon as the gas
Ions are produced by bombarding the gas with electrons generated by the hollow cathode which is heated. (once the process is started the cathode can self heat using the plasma bombardment)

i am struggling to remember much of the details to be honest. what i was looking at was seeing if it was possible to numerically model the way the gas passed through the hollow cathode to see if there was stuff that could be done to stabilise the flow. because the gas is both a gas and a plasma and is therefore influenced by normal fluid rules as well as electric and magnetic field effects, the rules governing how the flow works were extremely complex and not really understood. My research was trying to find some equations that could be used to describe the flow and then look at producing a computational fluid dynamics model that could be applied to it.

as such most of the stuff i looked at was fluid mechanics rather than actually understanding how the engine as a whole worked. There was another guy running physical experiments focused on that

Sorry, i had a retard moment in replying to you post. typed something completely different to what i was meant to. i typed does not neutralise gas meant to type does not re-harness exhaust. not even close. am tired

Searching for stuff found a paper i published ages ago

http://adsabs.harvard.edu/full/1997ESASP.398..217M

and if you are interested this is a good description of how the hollow cathode works.

http://descanso.jpl.nasa.gov/SciTechBook/series1/Goebel_06_Chap6_cathodes.pdf

have not looked at this stuff for so long. Bought a text book recently to start learning about flight mechanics again. just to use my brain for something other than fixing code bugs and writing cycling threads

Look again at that dot. That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every "superstar," every "supreme leader," every saint and sinner in the history of our species lived there--on a mote of dust suspended in a sunbeam.

The Earth is a very small stage in a vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that, in glory and triumph, they could become the momentary masters of a fraction of a dot. Think of the endless cruelties visited by the inhabitants of one corner of this pixel on the scarcely distinguishable inhabitants of some other corner, how frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds.

Our posturings, our imagined self-importance, the delusion that we have some privileged position in the Universe, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity, in all this vastness, there is no hint that help will come from elsewhere to save us from ourselves.

The Earth is the only world known so far to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment the Earth is where we make our stand.

It has been said that astronomy is a humbling and character-building experience. There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we've ever known.

-- Carl Sagan (1934-1996) talking about the Pale Blue Dot, known to all of us Earth.

i just posted some NASA pics in the chaos thread. why? because i like them there.

Do not like .

Do not like .

too bad for you ;D