Starship Asterisk*

Ann wrote:Fantastic image Chris, and talk about dark skies. But Nitpicker, yours is great, too. The color difference between the Hyades and the Pleiades is subtle but absolutely lovely. For an 8 second exposure, surely that is wonderful.

(Although, in a fit of hemisphere chauvinism, I felt tempted to exclaim: Hey, the sky is all upside down!!!)

Ann

Thanks Ann. The colours are easier to see in my full resolution original, but the stars of the Pleiades were rather distorted by my lens, so I think the reduced version is actually better overall (and within Starship size limits). Orion the hunter's head is in the North and he appears chauvinistic towards the South ... he appears to be looking up (or down) the skirt of a pretty Australian native (palm).

Nitpicker wrote:

Ann wrote:Fantastic image Chris, and talk about dark skies. But Nitpicker, yours is great, too. The color difference between the Hyades and the Pleiades is subtle but absolutely lovely. For an 8 second exposure, surely that is wonderful.

(Although, in a fit of hemisphere chauvinism, I felt tempted to exclaim: Hey, the sky is all upside down!!!)

Ann

Thanks Ann. The colours are easier to see in my full resolution original, but the stars of the Pleiades were rather distorted by my lens, so I think the reduced version is actually better overall (and within Starship size limits). Orion the hunter's head is in the North and he appears chauvinistic towards the South ... he appears to be looking up (or down) the skirt of a pretty Australian native (palm).

You mean

We are supposedly in the middle of the wet season here, yet we've mainly just seen lots of cloud and only a little rain, which in no good for anyone. But I did spot a patch of clear sky just after sunset on Sunday -- enough to capture the two and a half day old Moon, still in fairly bright twilight and only ~15° above the horizon. From left to right in the image (South to North around the eastern limb of the Moon) one can see: Mare Australe, Barnard, Humboldt, Mare Smythii, Neper, Mare Margini, Plutarch and Gauss.
This is a stack of the best ~30 of ~50 DSLR sub-exposures, through a 6" SCT, each 1/400 seconds at ISO 800, aligned and sharpened with Registax, cropped and reduced. I was aiming for a compromise between smooth aesthetics and sharp contrast, despite not really knowing what I am doing with image processing in general. Still, I'm pretty happy with it.

Tonight at dinner, out on the deck, I looked up and saw the Moon and Jupiter within about five degrees of each other. Then I looked down and saw them again, reflected off my dining table.

Did you get a couple of Jupiter's moons in that sky shot, too, or do my eyes and/or monitor deceive me?

owlice wrote:Did you get a couple of Jupiter's moons in that sky shot, too, or do my eyes and/or monitor deceive me?

No, not in those shorter exposures (which were also reduced). But with a longer, cropped exposure, you can see all four moons in a row, along with a nearby star. Not my best work.

Aurora !

9 years since I last saw it . . 9 long years of looking on every clear night opportunity, hoping!

But it was worth the wait; red, amazing, beautiful, no more words needed!

This evening, I caught a pretty Iridium satellite flare (I assume) streaking through Hyades: Later on, I had some bright, colourful, noisy fun with Omega Centauri, exaggerating the colours to produce these variants (just 3.5 minutes of usable data, hacked to oblivion in Deep Sky Hacker [I mean Stacker]):

The Moon rising behind Pikes Peak (14,114 ft / 4,302 m), about two and a half hours before sunset. You can see a couple of sections of the Pikes Peak Highway,

Fantastic picture, Chris. The Moon looks like a huge, ethereal, perfectly spherical, white balloon.

Ann

Chris Peterson wrote:The Moon rising behind Pikes Peak (14,114 ft / 4,302 m), about two and a half hours before sunset. You can see a couple of sections of the Pikes Peak Highway,

I am surprised at just how full the Moon looks, when rising two and a half hours before sunset. Half a day later and halfway around the world, I'm looking at the Moon and it is still not looking that full to me. Pikes Peak looks great, but is the full appearance of the Moon an optical illusion?

Nitpicker wrote:I am surprised at just how full the Moon looks, when rising two and a half hours before sunset. Half a day later and halfway around the world, I'm looking at the Moon and it is still not looking that full to me. Pikes Peak looks great, but is the full appearance of the Moon an optical illusion?

I was surprised by this, as well. I expected it to appear slightly more gibbous. The phase when rising was 93%. If you look closely, the bottom edge is definitely a bit fuzzy. By measurement, the Moon is about 3% wider than it is high... but how much of that is from the phase and how much from atmospheric refraction is hard to say. I think that the slight haze has reduced the contrast and made it hard to see the phase, so our brains fill in a circle... a kind of optical illusion, as you surmise.

Nice shot of the Peak.
At 14000+ feet elevation it is an impressive site though not as tall as Mount Sharp from crater floor, Curiosity's target

BMAONE23 wrote:Nice shot of the Peak.
At 14000+ feet elevation it is an impressive site though not as tall as Mount Sharp from crater floor, Curiosity's target

And I'm viewing it from a 9100 foot base. From the other side, in Colorado Springs, it's seen from just 6000 feet, making it even more prominent. Unlike most of the peaks in the Rockies, it's not part of a longer range, but a batholith- a single massive granite extrusion. Without nearby peaks for reference, Zebulon Pike (from the lower side on the plains) estimated it at over 17,000 feet and unclimable. Now you can do it as a long day hike, drive up, or take a cog railway.

Or, if you're in a hurry... Rob

rstevenson wrote:Or, if you're in a hurry...

794px-Tajima2011pikespeak.jpg

I'll pass. If you take the regular slow drive up the highway, you'll notice that many of the sharper bends are named after the person who went over the edge there.

Racers just love to honour the (in this case, aptly named) fallen. I think you'd have to be a little over the edge to race on that road in the first place.

Rob

rstevenson wrote:Or, if you're in a hurry...


Rob

I would like to see one of those do this

I wouldn't. Quit trashing up the landscape with auto tracks!

And tonight, an hour later and 5° further south.

It's really ghostly now!! ::insert scary insane laugh here::

Chris Peterson wrote:And tonight, an hour later and 5° further south.

Today's appears more gibbous than yesterday's, when it is actually fuller. Very weird. I (roughly) measured yesterday's Moon on your image, too, and only estimated a 1% difference between the Moon's E-W width and N-S height.

I wonder if there was some unusual distortion of light over the peak in yesterday's image, possibly a superior mirage over the cold mountain? I would have thought that ordinary atmospheric refraction would be minimal when the elevation angle of the Moon is high enough to see it over the peak. And the effects of refraction near the horizon normally makes the Moon seem shorter and wider, rather than fuller, doesn't it?

Nitpicker wrote:Today's appears more gibbous than yesterday's, when it is actually fuller. Very weird. I (roughly) measured yesterday's Moon on your image, too, and only estimated a 1% difference between the Moon's E-W width and N-S height.

I wonder if there was some unusual distortion of light over the peak in yesterday's image, possibly a superior mirage over the cold mountain? I would have thought that ordinary atmospheric refraction would be minimal when the elevation angle of the Moon is high enough to see it over the peak. And the effects of refraction near the horizon normally makes the Moon seem shorter and wider, rather than fuller, doesn't it?

I'm not aware of any atmospheric effects that can smoothly stretch something on the horizon vertically. I'm still leaning towards the issue here being ambiguity of the terminator location caused by the small difference in intensity between the Moon and the surrounding sky.

So, the first image I posted was very slightly processed from the camera's JPEG image- a tweak in color temperature, a touch of an "S" applied using curves, a weak unsharp mask, crop and resize. But I also have the image in RAW format, which means a lot more intensity levels are available. So I took that image, and performed exactly the same steps, and it certainly looks different now. I think it's just the greater range of real data right in the intensity zone defined by the sky and the terminator- when the "S" stretch occurred, the intensities remained, and weren't compressed out. Anyway, I think this is a better image and more accurately shows the true shape of the Moon that afternoon.

Chris Peterson wrote:So, the first image I posted was very slightly processed from the camera's JPEG image- a tweak in color temperature, a touch of an "S" applied using curves, a weak unsharp mask, crop and resize. But I also have the image in RAW format, which means a lot more intensity levels are available. So I took that image, and performed exactly the same steps, and it certainly looks different now. I think it's just the greater range of real data right in the intensity zone defined by the sky and the terminator- when the "S" stretch occurred, the intensities remained, and weren't compressed out. Anyway, I think this is a better image and more accurately shows the true shape of the Moon that afternoon.

Very interesting. Goes to show the power of image processing. I am learning on my own images that it can be used for both good and evil. Pity I have trouble telling the difference sometimes (at least as far as images go).