Starship Asterisk*

The Hourglass Nebula is the brightest part of the Lagoon Nebula. It shows up well in this Anglo-Australian Observatory photo. A Hubble picture of the Hourglass Nebula can be seen here . The alluring color view was captured with a telescope and digital camera while M8 was high in dark, rural Argenti...

Anyone know what the in-fall time of a comet is from, say, Neptune? A year maybe? I suspect it's one over root two of the orbital period, assuming it starts from Neptune's orbit and zero velocity. That seems like a very long time for a comet to fall from such a tiny distance so the initial velocity...

Again, "vertical separation" is meaningless. Every body is orbiting on its own plane, with the Sun at the center, and crosses Earth's orbit perfectly in two spots. Edit: that's still not quite clear, I think. Not every pair of inclined eccentric orbits have to intersect at two points (or ...

I've searched for but never found anything discussing what may happen if a PHA strikes the Moon. Depending on size, speed, angle, and location it seems like any effects could range from visually spectacular to deadly. "Moonfall", Jack McDevitt. Highly recommended, though there is a slight...

Unfortunately since I am still learning how to take the photographs they are not as high quality as they could be. If this is an example of you not at your best I *really* want to see what you do when you do better. It's gorgeous. It's beautiful. It's a lovely image, thank you. If you don't mind, I...

Is it possible that the SMC & the LMC at one time was (were) one galaxy and that the Milky Way ripped it apart? :? If so you would have to explain why the two have distinctive chemical compositions: <<[Andrew J. Fox]'s team found a low amount of oxygen and sulfur along most of the stream, match...

neufer wrote:

[b][color=#0000FF]Image credit: J-P Metsavainio of Astro Anarchy:[/color] http://astroanarchy.blogspot.fi/[/b]

---

Now *that* is so cool!
Thank you.
G.

Twisting near the center of the Lagoon, the small, bright hourglass shape is the turbulent result of extreme stellar winds and intense starlight. "Hourglass shape"? I can see a dark, demented, rabid meerkat off to the right and a dark sidewinder to left of centre but no hourglass. Is my p...

Every time this object is featured I am bothered by the coincidental ring galaxy in the gap. It's very tempting to say it's some kind of cosmic joke. "Let's make this type of galaxy quite rare and then stick another one of the same type right here so that the Earthlings will have something to ...

<<snipped>> How Hoag's Object formed remains unknown, although similar objects have now been identified and collectively labeled as a form of ring galaxy . Genesis hypotheses include a galaxy collision billions of years ago and the gravitational effect of a central bar that has since vanished . It'...

Actually, nobody has much idea how globulars form. Coming somehow from collisions is only one idea. They are not well understood phenomena. Sir, thank you, your post was far clearer than mine. I guess that comes of you being a real, practising Scientist while I'm mostly an autodidactic dilettante. ...

I'm still puzzled by the structure of globular clusters, or rather the apparent lack of it. Spiral galaxies 'obviously' rotate, the velocity of individual stars keeping them in orbit around the common CoG, and mutual attraction organising them into spiral arms. It seems as if the laws of physics ac...

Does it rotate 'in one piece' rather than as a swarm of stellar bees? John The stars orbit the center of mass, with no doubt a lot of perturbations. Apparently there's still enough room between stars (a light week is still a long way) that they don't collide very often. So from a distance it may se...

Today's APOD is of unwordly beauty, a magical view... Thanks Geckzilla, the big version came in perfect for my Spanish version of the APOD. I've looked and looked but I can find no beauty in today's APOD. There is something oddly askew with my sense of aesthetics, and I mean no offence to the photo...

a sphere 1400 kilometers in diameter of water. ok ... now let's calculate how much trash, garbage, polluted runoff and sewage is dumped into it each year by 7 billion humans. maybe you can tint it brown in proportion. blue is much too optimistic. That works out to each person on the planet having t...

[ I'm not a mathematician so excuse my ignorance but, does one milliard equal one million mallards? A milliard is one millionth of a billiard. Or a billionth of a trilliard. Looking at it from the other direction, a milliard is a thousand, thousand of thousands. Mallards are canards which I do not ...

WOW! What an awesome spectacle. It looks like a large burning doughnut, with flames coming off of it. So sharp and detailed. Below is my best image of M57. A far cry, but I only have a ground based, 10 incher... I enhanced the photo on my tablet. Not as sharp as my eyes aren't so good for focusing....

We should all be truly humbled by this picture. We sit here on Earth worrying about how much energy our little planet is accumulating yet in this picture the outer rings are at approximately 5x the distance from our Sun to Pluto from their own central star. Even at that distance the light energy is...

I used the Internet extensively before the WWWeb was designed by Sir Tim. Once web-pages began to be common, I spent quite a lot of time looking for really interesting ones and forwarding their URLs to friends and family. APoD was one of the early good sites I found and passed on. It has been the ho...

I made APOD my homepage a bit over 6 months ago, & enjoy trying to learn something new each day--even though much of it is way over my head. And some days I just sit & thrill at looking at beauty I would otherwise never see. I usually try to follow the underlined words to other pages. (Is t...

A little bit under 2 years, since I discovered you. You're not well publicized, so to speak, and if astronomy enthusiasts hadn't started a thread about space on our forums, I still wouldn't have heard of you. :) Moira, where would you publicise such a thing? APoD has been mentioned on UKland's BBC ...

THANK YOU! Enjoy especially the pictures of the planets with their rings and satellites. Why are so many, if not all, satellites in the same plane? Much I don't understand, but that doesn't stop me from enjoying and appreciating the picture. I may not check daily, but I do catch up on all. Staggers...

Had to put my guess at between 5 to 10 years. I'm sure I visited it many times over 10 years ago before actively following it. "Follow" is slightly ambiguous, I would have preferred something like "viewed" or "looked at" or "visited". I've had APoD as my home...

Galaxian - I think Ann was referring to the elliptical galaxy that is at the 11 o'clock position to the core (orient 3 and 9 o'clock to the dust lane) The bright thing between the two really tiny spirals? I though that was a foreground star. Sorry. Even on the largest sized image available it looks...

The small galaxy is so featureless that it's hard to say if it's a satellite galaxy or a more distant galaxy, but its non-reddened color suggests that it is nearby. If so, it might influence the star formation in NGC 891. Fascinatingly, there is also a small round satellite galaxy just "above&...