Starship Asterisk*

This is one of the best examples I've seen, all done with simple equipment if the shadow image of the photographer is representative. Again, with that assumption, consider the problem of maintaining the orientation of the camera for all exposures over a year's time. Maybe he erected a tent to protec...

Thanks Chris. Guess I read the commentary a little too quickly.

I'm a little confused by a couple things. The APOD commentary says that Betelgeuse, a red giant, may go supernova in the next few thousand years. But my limited understanding of red giants is that when the star 'blows' it produces a planetary nebula and the core of the star collapses to a white dwar...

First and foremost, I have to give three cheers to JPL and the folks at Tucson for a flawless landing of the Phoenix. Makes me proud of being a native of Arizona. I have seen two versions of the wideangle photo of the plain where the spacecraft landed showing the landscape to the horizon; the first ...

This is just a comment about the APOD: If this is a sample of the image clarity we may expect when the New Horizons spacecraft reaches Pluto, I await those images with great anticipation. I congratulate the designers and builders of NH. Well done!

I had some of the same objections to this mission as FieryIce. But your explanation, iamlucky13, clears up most of my concerns. Thanks! Btw, does anyone know how deep the lander is capable of digging/coring? Hopefully there won't be a repeat of the ambiguous results we all remember. My lingering con...

In today's artist conception of the quadruple star system HD 98800 http://apod.nasa.gov/apod/ap070730.html the dust clouds appear to be in a circular orbit. I'm wondering, however, whether dust orbiting any double star system ought to exhibit a more complex pattern. I have no idea what that pattern ...

Huge worms on Mars? Oh, dear! Maybe we should consider renaming the planet "Dune".

I couldn't resist!

Face it. It's the USA's last link with real culture & civilisation. :D :shock: Why else would you hang on so to a complicated system like that? Personally I still talk about pounds, shillings & pence, (& florins ie two-bob pieces, half-crowns ie "two-and-a-kick", & Aberdee...

Thanks for a great image, aichip.

The ball and socket are held together by a bolt. During launch, this is an explosive bolt that is triggered by the computer to jetison the tank when empty. I'm pretty sure they use a normal bolt for ferry flights. One would hope so, eh lucky? Then again, what was the Mars mission where some whizkid...

NGC 2903 is an extraordinarily beautiful object. I take it that the 'bar' in this particular barred- spiral is unusual in having many star-forming regions, rather than being comprised of mainly old stars. Is it possible that the core of NGC 2903 may have been infused with gas and dust through a gala...

At the risk of exposing my ignorance, let me ask a question. I was impressed by the extraordinary detail in the dark side infrared image. If the heating is endothermic, wouldn't there be more uniformity in IR radiation? I am assuming that endothermic heating would originate from the core of the plan...

one mile -- 1.6 km -- 4.94 Eiffel Towers 570 feet -- 175 m -- 190 shoelaces 300,000 ton -- 272 million kg -- 359,000 Volkswagon Beetles 130 feet -- 40 m -- 130 breadboxes 26,000 miles per hour -- 41,839 km/h -- 19.3 times the Concorde 9 miles across -- 14 km -- 3431 Volkswagon Beetles Laughed so ha...

Hey all, I just saw this featured on Slashdot. Interesting! I understand that the Mars Reconnaissance Orbiter (MRO) has ground penetrating RADAR (on board primarily to look for subsurface water ice deposits) with a resolution of about 30 ft. Seems to me that looking for subsurface voids (lava tubes...

I've always wondered why analemmae seem to have about the same angle to the horizon. Does it have anything to do with the latitude of the observer? Ok. On reflection, I can see that my question was stupid. :oops: Obviously, an observer in Anchorage, Alaska (for example) would observe a virtually hor...

Hi Gorade, I agree it's a pretty remarkable picture; makes one appreciate how rough terrain can be in the absence of wind and water erosion. If I am correct in identifying the feature that you cite, I would guess that it is probably an artifact. Bear in mind that we are talking about 40 year old tec...

Just want to express my appreciation to the moderators and all the folks who bring us the APOD. Well done!

Today (June 16th) I count 16 SPAM postings - a new high (or low) in my experience.

But I suppose that I shouldn't be surprised. Reminds me of my own email inbox!

I think I would like to have a bit more info before a definitive statement about what I think it is. For example, what was the sun angle when the picture was taken? If the sun angle was very low, then everything I see could be consistent with the collapsed roof of a lava tube. In the extremely thin ...

Thanks Pete. :) I feel a little foolish I didn't check the Wiki article first. :oops: I spent a little time with a CAD drawing program to explore variations on the drawing in the Wiki article to satisfy my curiosity. It turns out that an ordered rotation of the elliptical orbits of gas, dust and sta...

From our perspective, I would agree that M81 appears to be spinning in a counter-clockwise direction. I use as my model the appearance of water spinning as it goes down a drain. Thus the shape of the spiral arms appears to conform to my model of a counter-clockwise spin. Of course, viewed from the o...

Look closely at the center of the image, at the 4 large elliptical galaxies and you will see a small blue galaxy in the middle of the pack. (It is shaped like a "B" of sorts.) This is one of the galaxies that are being lensed by the cluster. There are 4 or 5 occurances of this galaxy with...

As I view the spectacular picture of the Globular Cluster M13, I imagine that the sight from a hypothetical planet at its core must be like Times Square on a busy night. But a few quick calculations on the back of an envelope have convinced me otherwise. It turns out that the average distance betwee...

I'm a little puzzled by the 15 May 2007 APOD. Aside from the yellowish core of the galaxy, depicting cooler, older stars in the core of M81, I also see many yellow colored circles far from the core. A few of the circles are very large. Are these displaced yellow circles representing old, cool stars ...