Explanation: Clouds of glowing gas mingle with dust lanes in the Trifid Nebula, a star forming region toward the constellation of the Archer (Sagittarius). In the center, the three prominent dust lanes that give the Trifid its name all come together. Mountains of opaque dust appear on the right, while other dark filaments of dust are visible threaded throughout the nebula. A single massive star visible near the center causes much of the Trifid's glow. The Trifid, also known as M20, is only about 300,000 years old, making it among the youngest emission nebulae known. The nebula lies about 9,000 light years away and the part pictured here spans about 10 light years. The above image is a composite with luminance taken from an image by the 8.2-m ground-based Subaru Telescope, detail provided by the 2.4-m orbiting Hubble Space Telescope, color data provided by Martin Pugh and image assembly and processing provided by Robert Gendler.
This is a truly fascinating image, which shows all sorts of jet-like protuberances in this very young region of ongoing star formation. The colors, while mapped, manage to look good, too.
Ron wrote:Are there any estimates out there of how much of the universe is thought to be dust ?
APOD pics frequently mention it, but has it been quantified ??
A quick google didn't actually turn up any numbers.
That's a good question Ron. If you were asking about gas instead of dust you likely would have found an answer, but dust is tougher to quantify I would think. "Dust" in space is what's also referred to as "metals"; elements other than H, He & li that have been produced by fusion in stars and then blown back out into space where it cools off and clumps together. I look foreword to seeing the answer to your question too.
Just as zero is not equal to infinity, everything coming from nothing is illogical.
I don't have an answer to how much dust there is in the universe, but let's start by saying that ordinary matter makes up 4% of the universe. As for the dust, remember that it is being continually created by massive and intermediate-mass stars, so that more and more of the ordinary matter in the universe is going to be dust (that is, little lumps of matter made up of silicon, carbon, water ice and so on). At the same time, as the universe continues to expand and accelerate, less and less of the universe is made up of ordinary matter at all.
So galaxies tend to get dustier over time, but then there are many things that vacuum up the dust too, everything from planetoids to protostars on up to supermassive black holes. Most giant ellipticals don't appear to have much dust, or do they and we just can't see it?
Just as zero is not equal to infinity, everything coming from nothing is illogical.
BDanielMayfield wrote:So galaxies tend to get dustier over time, but then there are many things that vacuum up the dust too, everything from planetoids to protostars on up to supermassive black holes. Most giant ellipticals don't appear to have much dust, or do they and we just can't see it?
Here is an (old) article about dust in elliptical galaxies.
Personally I suspect that there is more dust in elliptical galaxies than we can see. Typically, dust in elliptical galaxies don't settle in thick nebulae, which are not only strongly visible but are also able to give rise to new stars. Instead the dust is likely "spread thin" all over the elliptical galaxies.
<<The Great Gazoo is a tiny, green, floating alien who was exiled to Earth from his home planet Zetox as punishment for having invented a doomsday machine, a weapon of immense destructive power. His invention was a button which if pressed would destroy the universe in an explosive "ZAM," though he insists he made it on a whim ("I wanted to be the first on my block to have one!") with no intent of using it. Gazoo was discovered by Fred and Barney when his flying saucer crashed; Gazoo recognizes Fred and Barney's world as prehistoric Earth, implying Zetox banished him through time as well as space.
Gazoo refers to Fred and Barney as "dum-dums" and constantly causes problems for them. He can materialize and dematerialize objects, teleport, freeze time, travel through time (but apparently not through space), and perform other remarkable feats, but when he attempts to help out Fred and Barney, he usually ends up causing even more trouble. The only people who are able to see him are Fred, Barney, and the children, because they believe in him; animals can also see him. A running gag is that Fred argues with Gazoo while Wilma believes that he is talking to himself. When their daughter, Pebbles, says "Gazoo," Wilma thinks Pebbles is sneezing.
Gazoo's name actually derives from the 1909 hit song, "King of the Bungaloos," by Charles Straight and Gene Greene. In it the narrator explains, "I just received a cable 'spatch from my ancestral home. It tells me I'm the great Gazoo, successor to the throne." Because Gazoo is introduced into the show midway through the final season and is considered by some to be an absurd character, he is often cited by fans and critics of the show as being an example of the show's having "jumped the shark." In all, Gazoo appeared in 11 episodes.
Joanna Lee as Tanna
The story arc regarding Gazoo trying to return home is never resolved because of the cancellation of the original series, and the character does not appear, nor is he referred to, in the immediate series follow-up The Man Called Flintstone (1966) or any of the later spin-off TV series or animated movies, rendering him effectively dropped from continuity. He played a major part in The Flintstones in Viva Rock Vegas (2000), in which he is portrayed in a more positive tone. The film is set before the original series, but the live-action motion pictures did not follow the cartoon series' continuity. In the film, Gazoo is exiled to Earth in order to study the mating habits of humans as he is the most expendable of his race, as well as a punishment for his annoying ways. Throughout the film, he aids Fred and Barney in wooing their future wives, Wilma and Betty. As he does not appear in the original film which was set after this one, it can be assumed that Gazoo was allowed to return to his home planet after discovering the meaning of true love.
The Great Gazoo is referenced in The Simpsons episode "The Simpsons Spin-Off Showcase", a metafictional episode looking at alleged future developments in the series that would never come to pass, which include Ozmodiar, a floating green alien that only Homer could see.>>
Some of the comments suggest the image was a collaborative effort between all the parties in the
credit line. In actuality the image was conceived, assembled, and processed by me. I had the idea
of using HST and Subaru data to create it but needed NB color in HST palette to go along with the
HST data so I found Martin Pugh's nice NB image of M20 and he gave me permission to use it.
So although the image data came from multiple sources the idea and work done to combine all
the data was my own.
robgendler wrote:Some of the comments suggest the image was a collaborative effort between all the parties in the
credit line. In actuality the image was conceived, assembled, and processed by me. I had the idea
of using HST and Subaru data to create it but needed NB color in HST palette to go along with the
HST data so I found Martin Pugh's nice NB image of M20 and he gave me permission to use it.
So although the image data came from multiple sources the idea and work done to combine all
the data was my own.
Robert Gendler
Yes, I'm one of those who thought this was a collaborative effort. Thanks for telling me that this is your own work. Congratulations on a great picture!
Ann
Last edited by Ann on Mon Jan 28, 2013 2:01 pm, edited 1 time in total.
Ron wrote:Are there any estimates out there of how much of the universe is thought to be dust ?
APOD pics frequently mention it, but has it been quantified ??
A quick google didn't actually turn up any numbers.
In spiral galaxies, several techniques find that the dust mass is about 0.6% of the gas mass (atomic plus molecular hydrogen, mostly). This comes from far-infrared dust emission and optical absorption, giving about the same answer, as well as comparison of individual lines of sight in the Milky Way and its neighbors.
In elliptical galaxies, we know that they can't be deeply packed with dust for several reasons. When we see them overlap, any reddening or extinction from diffuse dust absorbing the background light is too weak to detect (which usually means less than 1% light loss). Similarly, their colors (spectral energy distribution) match the colors inferred from the strengths of absorption lines in stellar spectra. We do clearly see small-scale dust features - rings, wisps - in some ellipticals, especially common in those with strong radio sources. Most of the gas in ellipticals will be very hot - 10 million Kelvin or so - which is very unhealthy for grains, and can destroy dust grains in a cosmically short time (although grain production will be ongoing from giant stars, novae, and supernovae).
Pinging the site admins: Your "previous" link is actually pointing to the APOD for Jan. 29th (which doesn't exist yet), while the "next" link is pointing to yesterday's page!
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk. — Garrison Keillor
Uh...WOW!
Thank you for producing this awesome image. I've never seen the Trifid Nebula look so fantastic!
"A number of amateur astronomers now do photography and image processing that rivals the work of professionals and complements their work. But few are as talented and hard-working as Robert Gendler, a Connecticut physician, astronomy devotee, and author." - http://www.robgendlerastropics.com/Astr ... endler.pdf
I concur.
--
Obquote: "Baby, I'm amazed..." -Sir Paul McCartney (extracted completely out of context without permission of the author.)
neufer wrote:
You should get out more often, Beyond.
(To find the Truth, you must go beyond Beyond.)
Well, I'm no longer like the Beach boys. I don't "get around" much these days.
Considering that Truth is stranger than fiction... you wouldn't want to go beyond Beyond It is stranger than Strange there You'd just be trying to understand it.
Isaac Asimov wrote a book “The Stars, Like Dust” but I’ve never understood the comma in between? It seems to me “The Stars Like Dust” might have been more appropriate. This APOD seems to demonstrate that well.
But I would never claim to say one of my favorite sci-fi and non-fiction authors got it wrong. I’m sure someone out there knows why it’s punctuated like it is. I would guess he meant “As Numerous As Dust” What’s the latest guess? 10^78 to 10^84 equivalent of hydrogen atoms?
Ron-Astro Pharmacist wrote:Isaac Asimov wrote a book “The Stars, Like Dust” but I’ve never understood the comma in between? It seems to me “The Stars Like Dust” might have been more appropriate. This APOD seems to demonstrate that well.
But I would never claim to say one of my favorite sci-fi and non-fiction authors got it wrong. I’m sure someone out there knows why it’s punctuated like it is. I would guess he meant “As Numerous As Dust” What’s the latest guess? 10^78 to 10^84 equivalent of hydrogen atoms?
Yes, he meant it as "the stars, like sand on a beach". But I like your interpretation, as well. Interesting how radically the presence or absence of a comma can change the meaning.
Actually, I suppose stars don't "like" dust at all, as they never encounter it. As critical as dust is to the formation of stars (presumably, although not certainly), once a star turns on, that's it. No more dust, since the stellar wind blows it all away, creating a dust-free bubble around stars even in the middle of dust-rich nebulas.
Chris
*****************************************
Chris L Peterson
Cloudbait Observatory https://www.cloudbait.com
In the Center of the Trifid Nebula
You'd just be 
trying to understand it. 
