Starship Asterisk*

Paul Davies pondered just that.
http://www.nytimes.com/2013/11/19/opini ... .html?_r=0

Beyond wrote:Even though I'm no Astronomer, I would say that the tail, in "just the tail" link, is rather un-bright, although it does show up well against the background.

Its quite an interesting fuzzy.

jimbo48 wrote:There are several faint galaxies in the background.
Anybody know the designation of the bright galaxy below the comet in the frame?

NGC4697

Ann wrote: So when we greet our first alien, maybe we should use that little word common to us all - a resounding Huh???
Ann

geckzilla wrote:Yup, I've been through multiple lists of those. The list doesn't always match up with the descriptions for HubbleSite releases.

I noticed that.

I am pretty confused about filters and H-alpha and NII. When I look at Hubble images a lot of times H-alpha will come through the 658 filter and NII through the 656, yet both are called H-alpha filters. Sometimes they look very similar and other times they are quite different, which is really surpr...

http://en.wikipedia.org/wiki/Late_Heavy_Bombardment Of particular interest, Manfred Schidlowski argued in 1979 that the carbon isotopic ratios of some sedimentary rocks found in Greenland were a relic of organic matter. There was much debate over the precise dating of the rocks, with Schidlowski su...

It looks like it could be a single exposure tracking on the comet, which would mean a one shot color camera. :?: Looking at Damian's other comet pictures, I'm betting on the monochrome 6303 camera with a stack of several minute long luminance exposures and a short RGB sequence. If this was a single...

It looks like it could be a single exposure tracking on the comet, which would mean a one shot color camera.

So... Does the periodic table (which is the same table used by all aliens, everywhere), give up any clues about whether there are potentially other ways to create life besides "carbon based"? The answer will help us to know more about what to look for in potential habitable planet candida...

This?
http://www.galaxyzoo.org/

I got up to see the eclipse but the clouds didn't cooperate. There was a small break in the clouds, so I got off a couple of shots. Not much to look at but you can see it.

And thanks for your understanding, geckzilla. Ok, to put this back onto real astronomy, I do have a real astronomy question here. What causes some planets to “spiral in” or have their orbits decay over time. I know the inner moon of Mars is destined to do this, but why might this have occured in Ke...

OK, Chris
I guess read noise IS the limiting factor. So, after the images are stacked, as long as the SNR is at least 3 then it can be separated from the noise.

In terms of S/N, there is no difference between summing and averaging. It doesn't matter which you use. The average is just the sum multiplied by a constant, which affects the signal and noise equally. Median averaging results in poorer S/N compared with the sum or mean, but has the advantage that ...

In terms of S/N, it is always better to take a single exposure than to break that exposure into shorter subexposures and sum them. There are, of course, good reasons to build an image up from shorter exposures- advantages that often outweigh the reduced S/N that you inevitably get. I think you have...

http://www.astropix.com/HTML/J_DIGIT/COMPEXP1.HTM The formula for calculating the signal to noise increase when images are composited by averaging (adding the pixels in each image and then dividing by 2) is: n/SQR n... (n divided by the square root of n), where n is the number of negatives to be ad...

In response to your original question, adding(stacking) your exposures does not equal the sum of the exposures. It just makes for a cleaner short exposure. What taking a lot of shorter exposures DOES do is increase your SNR. Here is a link explaining just that. http://www.astropix.com/HTML/J_DIGIT/C...

Or, if your eye could store thirty seconds worth of photons, then relay them to the optic nerve, we could begin to compete with a camera. Of course, viewing our surroundings in thirty second intervals wouldn't be all that pleasant!

I think it is kind of amazing to think that WE - or the specific life forms on Earth - are so unique. At least I'm convinced that all the multicellular life forms that have ever existed on the Earth are unique to this planet. So take a look around, and consider the fact that it took the entire univ...

Nitpicker wrote: But one can still ponder the interaction between two distant galaxies, as in this APOD, with only a 19th century understanding. It still makes sense qualitatively.

To a non professional astronomer, observations, for the most part, are qualitative!

makc wrote:I misread your "critters" as "crickets".

Click to view full size image

That IS a stream of stuff, alright

My guess is the light source that is hidden behind the foreground rock, illuminating the other rocks with a greenish hue, is then reflecting off the incoming tide water, and illuminating the bottoms of the low clouds (fog) hovering just above the waters. I think you're exactly right. The low layer ...

2MASS 13393507-6722518
This is the star in question. I couldn't find anything on it.

geckzilla wrote:

stephen63 wrote:

geckzilla wrote:Maybe the sun between buildings again.

Don't you mean "ancient megalithic structures"?

No, I meant buildings. Like skyscrapers. Ancient megalithic structures are also an option, however.

Either way, you're probably right.