Starship Asterisk*

Thank you, Chris, geckzilla, and Ann. Very illuminating.

I have a basic question about what I see in many APODs. If you look at the small excerpt here, for example, the stars appear to come in many sizes and levels of brightness. Naturally, my brain wants to put the larger and brighter ones as closer (I assume that strategy is generally correct, but would...

Fantastic. I am a bit surprised that nobody had put this together in a movie before. And I suppose it was a lot of work. It looks great. There are obviously people at NASA (and some related companies) who do a lot of work animating, either with direct data such as this, or with a lot more artistic i...

They may wish Philae had wheel instead of legs to help that process though I'm sure Rosetta will scope out the comet quite well. If Philae had wheels it would likely roll right off the comet into space. You are right Geck. Spiderman would have a hard time navigating this terrain. …and sticking to i...

The last link in the APOD text points to the Dark Energy Survey website. I've never visited that site before. After reading through their overview materials, I noted that in two places, they give the same explanation of red-shift: This is known as redshift. Objects in space such as galaxies or explo...

This got me to thinking that some "man-made meteors" might be spectacular, if the ISS were lucky enough to catch a view of them. It turns out (as always) that NASA ad APOD are way ahead of me on that. There's a nice video of a Soyuz re-entry: https://www.youtube.com/watch?v=WmEzR3dGru4 , a...

I agree with metamorphmuses. My gut also tells me that the study of this location may bring a lot of new insights. My first question is about the central part of the image. Are there two galaxies that are almost in line from our viewpoint, are they not just in line, but merging, or, what seems much ...

Artistic Liberty :
http://www.travelization.net/2012/10/be ... apers.html

Image 7 is my favorite, because it shows the moon (... and a sunset ... I think).

Alright, where are the seams where MAHLI's arm is omitted from the panorama? Usually I can spot it but I'm having trouble this time. It's amusing to me that the rover can take just the right photos of itself to make it look like an external observer did the imaging. I'm not good at finding seams. T...

Fascinating! Thanks, Ann.

It would be awesome, if for some light echo as dramatic as this one, we could get the "real movie". If a space telescope had the time to take a picture a week or so for 10 years. Of course I don't know if it would do humanity any good (so who would ever fund that kind of telescope time), b...

.. If there are too many dust particles between us and the star, there will either be no reflection nebula at all, or else there will be a reddened, non-blue reflection nebula. ... Ann Since the appearance of a blue nebula was stated to be similar to the reason our sky looks blue, I wonder if there...

Ah, yes. I get it, you're right, of course. Ellipsoids.

@nitpicker. I think your diagram is great. If I understand it, the parabolas in your diagram show a 2-D indication of 3-D paraboloids (perhaps that's what they are) of points where: IF there was a reflective bit of dust there, it would be lit up in an image at the same time. And you could plot from ...

I'd love to see a simulation of light traveling through an irregularly shaped medium like this to help my brain cope with what the pictures show. Even the still frames are somewhat baffling to me. Yes, that'd be nice. The shape should be something like neufer's diagram showed. We know that all of t...

... wikipedia article ... Fascinating. So, we *have* had enough time to observe the expansion of some planetary nebula directly. That seems to provide a wonderful strengthening of confidence in the distance estimate. I suppose we don't know for certain that the nebula is spherical, but it would see...

How has an estimate of the age of the outer filaments been made? Basically he same way the age of the universe (from the Big Bang) is determined: 1) A Doppler measurement of the current expansion rate in combination 2) with a simple physical model of the average expansion rate over time. Run the mo...

That is a gorgeous image!
How has an estimate of the age of the outer filaments been made?

Sure, no analogy should be expected to be perfect. But some process has created and organized those dust lanes, although I agree the material in them is not necessarily "flowing in" toward the center. And some process has amassed 5 million solar masses in a compact region in the center, an...

Very nice sequence of images. It's surely a very exciting time for those who planned and executed this mission and have waited so long. I noticed that today (+/- 1) is listed as the "rendezvous" date in some of the materials describing this mission. Today's APOD ends with an image on May 4...

What detail...looks like you could just fall in ... "And away go troubles, down the drain...." :---[===]* I believe it is correct to view spiral galaxies as behaving much like a drain. The material is falling in as well as orbiting. And yet how different this is from our earth-bound human...

Thanks for that link, JohnD. That page is very nice and has much of the additional info that I think enhances the experience. Oddly enough, I watched the tracking move from over the water to over land, indeed hundreds of miles from any ocean (over South America), and still the live feed showed cloud...

This is really the bomb track! (when it's not gray). Thanks for linking to it. Mind you, it is kind of cheating for "A.P. of the Day", since I believe I'll be able to come back tomorrow, and the next day, and the next, and it'll be different all the time. I hope the editors aren't thinking...

It's something about the way they get lensed. There are always often oddly red cores with oddly blue arms for lensed galaxies. . . . I'm thinking that when we make our own lenses, we make them in a shape that is convenient, to produce good optical results. However, these natural gravitational lense...

Hmmm ... interesting. Warning to those who don't know me: The following is the musing of a rank amateur, so as you read this, be warned that it is not the least bit authoritative. I'm just thinking it through, wondering if I can make some correct statements about what is going on. I would assume met...