Starship Asterisk*

Radial velocity measurements have revealed that most globulars are moving in highly excentric elliptical orbits that take them far outside the Milky Way; they form a halo of roughly spherical shape which is highly concentrated to the Galactic Center, but reaches out to a distance of several 100,000...

Granted, we would need much larger eyes to see radio waves. But brain size would not have to change. In fact, resolution with longer waves generally declines, meaning less data to process. Also, the size of radio telescopes is related to "light grasp", ability to detect very faint sources,...

Yo, Orca! Our brains process sight and other sensory input in an essentially analog fashion. They would not need to be any larger or more powerful to handle a broader spectrum. Spectrum limitation is defined by what the cells in the retina detect. Consider the eagle -- he has far sharper eyesight th...

I went to the link. What "newest measurements of COBE" (not cited)? Looks like dubious science to me. I thought the speed of light is constant. The 3 degree cosmic background radiation is electromagnetic, so it has to clock at the speed of light, regardless of its direction. Oh, and it doe...

As far as "within" the galaxy goes, globular clusters are arranged in sort of a halo around the periphery of our galaxy and orbiting (with) it. The ones we can observe are overwhelmingly outside the spiral arms and out of the galactic plane. They are often considered (sub-galactic size) sa...

"True" color images (like the Ring Nebula shot) simply mean that the colors are as received by a visible light CCD or as they appear from a time exposure on ordinary visible light color film, with no filtering or color alteration, and no display of wavelengths outside the visible spectrum....

All this spinning and rotating is enough to make you dizzy.

"How fast are we going?" can only be answered "in relation to what?"

Yes, but can a stable gas giant planet exist in the "habitable zone"? I recognize that a few of the earliest identified planets around other stars appear to be extra large gas giants, ID'ed because of their close in, rapid orbits, which caused the stars to "wobble" measurably. Ho...

Harry, I am still having major conceptual problems with the sun having a neutron star at its core: 1. Neutron stars range from a substantial fraction of a solar mass, up to a few solar masses. Of course, our sun is only one solar mass, so the neutron star must be surrounded by a large, fairly tenuou...

Tradition! Harry is probably right. Hard to break old habits, even for the IAU. Personally, I agree with Nick. Pluto should be classified as a KBO, since its characteristics (small, icy, highly eccentric and out of plane orbit) put it solidly in that category. "Planet" should be formally d...

I always thought that it was a photo, taken through a telephoto lens... Lenses tend to enlarge everything equally, moon, sun, background etc. It might have existed some 4.3 billion years ago after the moon had just formed and was (17 times?) closer to us than it is now. Good thought, but both earth...

See Hideway may not be so far away for more discussion of the same topic.

Dang! Depending upon the angular size of the photo, either that sun is really far away, in which case everything should be frozen, and/or that moon is either really huge or really close, in which case you could expect massive tides on both bodies, enough to cause some nasty wave action on the primar...

Many scientists think that the main energy from the sun comes from fusion of H+ H >> He. Which astronomers do not believe this? The sun is supposed to be a G2 class main sequence star, 92.1% hydrogen, 7.8%helium (easy inference: < 0.1% anything else). http://solarsystem.jpl.nasa.gov/planets/profile...

Yo, Harry, Residual heat from planet formation, yes. Even the earth's geology is still powered by heat that has not yet escaped, and Neptune is far more massive. It is also in a much colder location, so it has lots more heat to lose to reach equilibrium. Earth's moon (a smaller body) in contrast is ...

Puh-lease when creating a new topic, give it a meaningful title, not just a date.

Belt of Venus looks worth reading, but APOD June 15, 2006 is pretty non-descript - and very similar to APOD June 12, 2006, which is about a completely different topic.

Thank you.

The "popular" usage goes back to before guys like Messier. To the naked eye, except for a few objects like the Pleiades (which as a young star cluster is surrounded by a faint nebula), it was not possible to resolve the stars. They all looked like fuzzy clouds. This use persisted even in a...

I don't know either, but I guess they estimate it crudely based on either optical density (how much light gets blocked from objects behind), or by estimating the cloud mass due to its gravitational effect on nearby objects or gravitational lensing of objects behind, and possibly subtracting the mass...

I am waiting to hear a physicist's response to Harry's comments. I once read a "non-technical" summation of Setterfield's work, and it seemed full of holes to me. But I have not had time to study his paper yet. I find thoughtful questioning of "orthodoxy" fascinating, and the str...

I guess that the rotation of any particular system is random. Note that individual galactic planes and apparent rotation appear random even in relation to the overall rotation of the groups to which they belong. In every treatise I have read on the standard model (almost unrecognizable now), or gala...

Amen. Great site. Makes my day.

It is possible (now anyway) to perform mapping (either limited in area or limited in detail) with some modern types of radar on a single pass. An active electronic scanned array / phased array would allow collecting a lot of data in a short time frame, and offers weight and reliability advantages (n...

Junk topics seem to be overwhelming the real ones. Makes the BB hard to read.

Or a prominent comet. Do they emit gamma rays?

I think you are right, just the tip of the Horn, although I did not recognize it at first because of the low angle, and direction (looking north-east). If you could see more of it, or Yemen across the water to the left, it would be clearer. How did you happen to notice?