Starship Asterisk*

I never click on the Digg links, and don't bother with the Digg site. It's a kind of social networking I'm not interested in. But it certainly doesn't bother me to visit sites that have Digg links- why should it? If it provides some value to you, as the APOD authors, great. It can be viewed as eithe...

How is the orientation of the photos decided? Many of the galaxies are "tilted", and would otherwise look very similar if the photos were rotated to lay them all flat. Most professional images are oriented north up, meaning that if you drew a line upwards, it would eventually hit the cele...

First of all, can anybody explain what this means? Preliminary indications are that the meteor stream is quite stable in time but variable in meteor abundance. Here's my interpretation: meteor streams vary in the stability of their orbits. That is, some streams are more influenced by gravitational ...

My memory tells me that all old moon maps said "IRIDUM" - is this the truth, a faulty recollection, or the particular maps they chose to give me as a child? Now I see both "IRIDUM" and "IRIDIUM" enough places to say that either spelling appears to be currently accepted...

Consensus of opinion in the car was that we were seeing sunlight coming over the Pole reflected upward by the polar icecap. Could be we had one of those rare nights when skies were clear all the way north to the pole. Quite impossible. Because of the curvature of the Earth, about the farthest you c...

There's two types of star clusters, open and closed. That should be "open" and "globular". In an open cluster, the stars are not gravitationally bound, meaning they have enough momentum to escape the group. As I understand it, open clusters are really just chance concentrations ...

Sorry but I am still confused... if there is no direction we can look and the origin lies outside the 3 dimensions we reference but at the same time we can look deeply in any direction and be closer to the origin... has thrown me into a tail spin. I can understand why we can't see the origin if we ...

I understand the WMAP CMB timeline graphic is only a schematic showing in simple terms what WMAP is teaching us (BTW thanks for the links) but my desire to understand almost requires that there be a tangible single point of origin we can locate or at least know which direction to look. Chris: I don...

Surely if magnitude 7 impacts are observed regularly today then larger lunar impacts must have been witnessed visually in the past but if such events were ever recorded then no record survives that we know about. That's an interesting thing to consider. Impacts large enough to cause an easily visib...

<<Five monks from Canterbury reported to the abbey's chronicler, Gervase, that shortly after sunset on June 18, 1178, they saw two horns of light on the shaded part of the moon: " This year, on the evening of June 18, when the moon, a slim crescent, first became visible, a marvelous phenomenon...

This image for some unknown reason set me to wondering about the relationship between time and distance as viewed from earth. If I understand correctly :?: If the universe were large enough and we could see far enough :?: we would see the original event at that point :?: Something like that. There ...

I don't know of any recorded incident of a meteor hitting the moon. but how would you record it? its not like the meteor will light up like it does in the earth's atmosphere. the moon is probably pelted with dust all the time since it doesn't have an atmosphere like the earth's. we can easily see m...

FieryIce wrote:You can side step the issue, go ahead but the facts remains.

Please quote who and what you are responding to. What issue exactly is being sidestepped?

They can take a picture of a planetary pole without the blacked out area, so there is no excuse for the data block out. Only if the camera can actually image the pole at some point in its orbit. As I noted before, the satellite is in a 97.8° inclination orbit. That means it never gets closer than a...

June 11, 2007 image of NLC's from the AIM satellite posted at Earth Observatory latest images. It is impossible to take a straight down picture and have the centre blacked out. The image wasn't taken straight down over the pole. The AIM spacecraft is in a 97.8° inclination orbit, so it never passes...

At the fastest rate that we can currently muster, it would take over 400,000,000 (4 hunderd, million) years just to travel 4ly to our next nearest stellar neighbor. Where did you come up with that? You could jog to the nearest star in that time! Voyager 1 is currently traveling away from the Sun at...

The dynamic range of a camera just isn't wide enough to capture both the very dim stars and the sunlit subjects at the same time. One additional comment: it is often believed that the stars appear exceptionally bright or numerous from space, but in fact, the attenuation of the atmosphere is slight-...

The argument the the universe is infinite "because" it has not been proved to be finite is far to passive of an argument for me. I'm not arguing that, and I don't see that anybody else is, either. The point is simply that nobody can say one way or the other whether the Universe is finite ...

This discussion has been going in circles for quite some time now. The bottom line is simple. From a scientific standpoint, it is currently unknown if the Universe is infinite. Nothing requires it and nothing precludes it. It isn't even known if the extent of the Universe can be determined. There ar...

Phil G wrote:My non-scientifically-trained mind is having trouble with this.
I presume that Planck's Lengths are mathematical units. Correct?

No, a Planck length is a unit of absolute distance, 1.6 e -35 meters. It's not a simple concept, but you can read about it in this Wikipedia article.

OK, Chris, I bite. I have to admit I appreciate your observations and explanations, sometimes I can even see where they're going before you get there. Most of the time they confirm what my limited expertise(?) has led me to believe. Now, I think I would like to see your explanation of how any point...

If you wish to try the Moon/ Star thing, it could be accomplished with some assistance. Go to a large open area. Either import large quantities of white sand (if on open ground) or if on black top, (like a parking lot) paint the entire surface white. Shine many large spot lights on the surface from...

If you wish to try the Moon/ Star thing, it could be accomplished with some assistance. Go to a large open area. Either import large quantities of white sand (if on open ground) or if on black top, (like a parking lot) paint the entire surface white. Shine many large spot lights on the surface from...

Yes, it would have to be the center of the observable universe since our observations are made from here. That it's in the center of the observable Universe is self evident. It's likely in the center of the entire Universe, as well, since- in three dimensions- any point in the Universe can be consi...

bystander wrote:I suppose next you'll tell me that earth isn't the center of the universe.

Of course, in a very real sense, the Earth likely is in the center of the Universe. It's just not unique in that respect.