Starship Asterisk*

The bar in NGC4449 looks like a helix, or a helicoidal structure. Have any galaxy specialists suggested this?

The caption says: "Researchers speculate that the cones viewed from another angle would appear similar to the gigantic rings of supernova 1987A, possibly indicating that a star in MWC 922 might one day itself explode in a similar supernova." But the link provided about 1987A (APOD, 7 Janua...

What is that dark spot on the picture's main object, Enceladus?

I am wondering why the body of the planet overlaps the rings in this photo. Was the spacecraft too close to get the gap? I think maybe that the photo is a mosaic pieced together may have something to do with it. Some pieces of the mosaic may have been a little too large to fit in properly; unless t...

Nereid wrote:Two threads on this APOD merged.

Next time, please give the new thread subject header so we can follow it. (I found the last message above by reviewing my own posts, but the trail ends here.)

Sure, we can look at it one way or another, the ceiling is a floor, etc. Craterchains, at least, mentions a certain "death wish" - but in media talk about supernovas the death wish isn't hidden, it's waved around like a flag. So why do we so readily attach our death-obsession to these magn...

Today's APOD (2006/10/26) talks of the "death explosion" of the star which produced M1. Why all this lugubrious buzz about "death stars", etc., when bursting stars are the initial propagators of life in the universe? We are made of, or depend on, the oxygen, carbon, silicon, iron...

The camera keeps the Earth motionless but speeds up the stars, so they become a vortex that sucks you in.

"The view looks to the south." But wouldn't it be southwest? If the view was due south, the pole (centre of the star trail circles) would be straight ahead.

Oh, duh! It's as if the artist thought, "Now how can I put realistic shadows here? Let me just put this lightbulb next to these upright pineapples..." When you say "parallel", you mean the shadows are parallel to each other, of course. Painters used to learn this in art school in...

Is there a line or group of words missing between the links "Mars" and "carbon dioxide"? I can't quite make out the sense.

It doesn't look like a safe place to be driving my Land Rover.

Okay, galaxies are mostly empty space: "...stars in the two galaxies - NGC 4038 and NGC 4039 - don't collide in the course of the ponderous, billion year or so long event." But surely it is possible for some stars to collide. A billion years is a long time.

Funny you should mention that... When I first saw this picture I thought it was taken from a vessel on one of Earth's near-polar seas, with a broken-up ice pack and big waves.

Thanks for the links. I don't think any of them answers my question, although the ESA page on the cluster quartet probes is very interesting. Two supplementary questions: (1) is anyone mapping/has anyone mapped the distribution of those "holes" in the ionosphere at any given time? (2) whil...

Woa, I am confused. The caption explaining why there are black gaps in auroras says "negatively charged particles may be sucked out from the Earth's ionosphere along adjoining magnetic field lines." It's the "adjoining magnetic field lines" that get me. Sure enough, large parts o...

Okay, my brain shall assume that galaxies extend to where their gravitational influence is in equilibrium with external gravitational influences. That would make an interesting 3-dimensional map of galactic "territories", filled with a spongy net composed of an uninterrupted gravitational ...

harry wrote:Hello Axel


Re:http://antwrp.gsfc.nasa.gov/apod/ap060302.html

The length is determined by the extreme observable edges.

This probably sounds sophomoric too but... I'm still in the dark. What defines the observable edges? (See my original post.)

Beautiful as always! Now, this galaxy is said to be "about 170,000 light-years across." What do I see in the picture? First, a strong concentration of white light around the nucleus; a little farther out, a dense swirl of stars and dust with a fairly tight vortex pattern; and much farther ...

The Mercedes-Benz people ought to fund a telescope with three brackets.

Absolutely stunning. I doubt the planners foresaw the profound aesthetic effect.

A big bruiser of a rocket. Yawn. I guess it appeals to the same guys who gawk at pictures of 1980s jazzed-up pickup trucks with mag wheels.

Don't tell me they're giving names to satellites of asteroids! Yikes!!! It's bad enough they must find names for the new (and ever more easily discovered) asteroids besides the 12,000 or so already baptized. And while I'm on the topic, I find it strange that with all the classical names apparently u...

I am almost sorry I posted this poll, especially since the low turnout ensures it won't be very useful. Also it may be too hard to choose. While I generally prefer deep sky images, and so cast my own vote accordingly, my single most adored picture of all APODs was this spectacular Earthscape: http:/...

Well, to answer my own question, the day must have been 26 January 1995. At least the morning (EST) of that day fits for the Moon and two planets. The question remains how the photographer was able to position a sequence of Suns at the same levels as the successive images of the other bodies. At Fir...

This beautiful picture was taken "ten years ago". Probably, therefore, it was taken either close to the Sun-Jupiter conjunction of November 1994 or that of December 1995. In the first case, when the Moon passed near Venus and Jupiter a month earlier, on October 9th, the Sun was about 30 ec...