New Discoveries *4* - ...Solar System, Deep Space, cont'd

John Creighton · 2004-12-03 21:55:29

Spooky. Is all that black empty space or dark matter?

GraemeSkinner · 2004-12-04 03:41:13

Spooky. Is all that black empty space or dark matter?

It says something about the lane being swept clean, but it would be good to see some alternative images of the area, perhaps infrared or x-ray?

Graeme

Palomar · 2004-12-04 07:37:01

Spooky. Is all that black empty space or dark matter?

*Hi John: It's not empty space. Found another caption with a bit more explanation (via one of the links in the caption accompanying that image):

What used to be considered a hole in the sky is now known to astronomers as a dark molecular cloud. Here, a high concentration of dust and molecular gas absorb practically all the visible light emitted from background stars. The eerily dark surroundings help make the interiors of molecular clouds some of the coldest and most isolated places in the universe.

Is distinct from http://en.wikipedia.org/wiki/Dark_matter]Dark Matter (unless I've got my wires crossed somehow).

--Cindy

Palomar · 2004-12-04 13:08:46

http://antwrp.gsfc.nasa.gov/apod/ap990604.html]From Beginning to End

*This Astropix feature does have it all: Stellar nursery, a dying supergiant star, emission nebulae similar to proto-planetary discs (raising the question if there are planets there), etc. Also includes Bok globules. Nice visual contrast as well.

-*-

http://antwrp.gsfc.nasa.gov/apod/ap981206.html]Ruptured Cometary Globule

*I think every school should require daily reading/viewing at Astropix! Could only have dreamed of a resource like this as a kid.

-*-

http://antwrp.gsfc.nasa.gov/apod/ap0012 … Reflecting Merope

*Ethereal. But besides aesthetics:

The cloud, known as IC 349, and the star have been in existence for millions of years. In the past 100,000 years, however, part of the cloud has by chance moved so close to the star - only 3500 times the Earth-Sun distance - that the star's light affects the cloud's dust in an unusual manner. Pressure of the star's light significantly repels the dust in the reflection nebula with smaller dust particles being repelled more strongly. Eventually parts of the dust cloud have become stratified and point toward Merope, with the closest particles being the most massive and so the least affected by the radiation pressure.

--Cindy

GraemeSkinner · 2004-12-07 06:00:02

Perhaps not the right thread to post this to but http://antwrp.gsfc.nasa.gov/apod/ap041207.html]Strange Streak Picture

Graeme

ERRORIST · 2004-12-07 07:57:59

Perhaps, a terrorists nuke that has gone astray and was intended for Australia????

Shaun Barrett · 2004-12-07 08:24:51

How fast can ball lightning move?
The sky looks threatening and there may have been considerable static electricity in the area. My guess is it's some kind of atmospheric electrical phenomenon.
I'm sure there are all sorts of things going on in the atmosphere that we've yet to fathom. Maybe we just caught one of them on camera(?).
???

Palomar · 2004-12-07 09:37:39

http://antwrp.gsfc.nasa.gov/apod/ap041207.html]Strange Streak Picture
Graeme

*To me it looks like a very narrow-field shadow effect from cloud-sunshine interplay. But I've never seen it this finely angled, defined nor narrow! Nor seeming all the way to the horizon, IIRC.

Graeme, you probably know this, but just in case: You'll have to re-insert the link again tomorrow via Edit. APOD does update and archive daily, of course. Unless you know a posting trick I'm unaware of!

Hi Shaun: I've never seen ball lightning. Would like to, though.

--Cindy

GraemeSkinner · 2004-12-08 22:28:38

http://antwrp.gsfc.nasa.gov/apod/ap041207.html]Strange Streak Picture
Graeme
*To me it looks like a very narrow-field shadow effect from cloud-sunshine interplay. But I've never seen it this finely angled, defined nor narrow! Nor seeming all the way to the horizon, IIRC.
Graeme, you probably know this, but just in case: You'll have to re-insert the link again tomorrow via Edit. APOD does update and archive daily, of course. Unless you know a posting trick I'm unaware of!

The first link should still work as it was from the apod archive page rather than the picture page itself (address should have the date tagged on the end in this case 041207 - for some reason its year month day).

I've seen two different suggestions so far which may be plausible - one is a firework rocket so we're seeing the flash at the bottom and the smoke as it goes away' and a flying bug close to the lens thats been caught in the cameras flash. (Still not sure its not photoshop though )

Graeme

Shaun Barrett · 2004-12-09 02:05:03

RATS!!
A mysterious atmospheric phenomenon would have been so much more fun than bugs and fireworks.

Palomar · 2004-12-10 12:09:18

http://www.universetoday.com/am/publish … ]Tarantula Nebula in Detail

*New images from European Southern Observatory. Yeah...impressive alright. :up: Real smorgasboard of cosmic goodies. Is viewable from the Southern hemisphere (Shaun, I envy you right now...).

Fernando Comeron: "This amazing concentration of clusters, HII regions, supernova remnants, and extremely hot and luminous stars in a single region makes the Tarantula in the LMC a unique celestial object, unrivalled in our own Galaxy and other nearby galaxies!"

-*-

http://antwrp.gsfc.nasa.gov/cgi-bin/apo … a]Astropix offerings (old articles) regarding this nebula

*Some of the articles are repeats.

--Cindy

Palomar · 2004-12-11 14:00:37

http://antwrp.gsfc.nasa.gov/apod/ap041207.html]Strange Streak Picture
Graeme
To me it looks like a very narrow-field shadow effect from cloud-sunshine interplay. But I've never seen it this finely angled, defined nor narrow! Nor seeming all the way to the horizon, IIRC.

*Nice timing coincidence. From spaceweather.com:

http://www.spaceweather.com/swpod2004/1 … g]*-This-* is what I had in mind, to explain the pic Graeme posted. There's a slight "fanning out" in this photo, as opposed to the neat narrowness of Graeme's APOD pic...but is what I had in mind.

Photo by Michael Blevins on Dec. 3, from Aruba (who said it lasted for an hour). The explanation is:

What is it? Atmospheric optics expert Les Cowley explains: "The blue beam piercing the twilit sky is a cloud shadow, a form of crepuscular ray. Somewhere over the horizon a tall cloud is blocking the sun and casting its long shadow through the sky. The dark shadowed air allows us to see the deep blue of the upper atmosphere through it.

*A bit unrelated to the actual "streak" but continuing quote:

Dust and aerosol in the surrounding unshadowed air scatters reddened sunset rays and mixes them with the blues of the upper atmosphere to give us the rosy and purple hues of twilight."

--Cindy

GraemeSkinner · 2004-12-11 14:11:54

I've seen so many suggestions as to what the streak could be, from aliens to exploding light bulbs, the spaceweather.com link looks like a shadow could be a possibility.
If you get really curious look at the (currently) 79 pages of the astropixs forum on the subject.

Graeme

Shaun Barrett · 2004-12-11 21:23:00

Awww .. come on Graeme!
Can't you just post the 79 pages here, to save us the trouble of going to the other site? ??? ( )

[P.S. Nice job on Ares Express, by the way. :up: ]

GraemeSkinner · 2004-12-13 03:26:45

Don't know if this has been already posted, but here are details of a new star (SIPS 1259-4336) http://astronomy.com/default.aspx?c=a&id=2650]LINK

Excellent image with the article too.

Graeme

*Shaun* Thanks for the comments re Ares Express

Palomar · 2004-12-15 07:39:18

http://www.spacedaily.com/news/jupiter- … c.html]New model proposed to explain Jupiter's core

*Really intriguing article. :up:

Discusses Jovian water, oxygen, carbon inventory. This model "assumes an outer solar system warmer than previously thought."

Lodders calculated that Jupiter is depleted in water and thus in oxygen. The Jovian oxygen inventory is only about half of the oxygen elemental abundance in the Sun.
On the other hand, the Galileo probe mass spectrometer data show that Jupiter's carbon inventory is about 1.7 times larger than that in the Sun. Based on these data, Lodders argues that Jupiter's core was mainly tar instead of ice.

Jupiter's core formed rapidly relative to the rate at which gas was lost from the solar nebula. Once its core reached about 10 Earth masses, gravitational attraction captured the surrounding nebular gas and built up the gas giant planet we observe today.

--Cindy

Palomar · 2004-12-15 13:19:09

http://www.universetoday.com/am/publish … 04]Shelter from the storm?

*Gap between Van Allen radiation belts not as safe as previously thought.

Scientists were surprised to learn that the Earth's magnetic field can concentrate radiation from the Sun during powerful solar storms, even in places that were previously thought to be safe. One region is the gap between the two Van Allen radiation belts that surround our planet, which resemble two donuts, one inside the other. In between these belts is a relatively safe area that could be prime real estate for satellites because of the low radiation levels. During the extreme solar weather last year, that safe zone actually filled up with radiation and became quite hazardous for more than five weeks.

--Cindy

Palomar · 2004-12-16 07:24:13

http://www.universetoday.com/am/publish … ]Tarantula Nebula in Detail
*New images from European Southern Observatory. Yeah...impressive alright. :up: Real smorgasboard of cosmic goodies. Is viewable from the Southern hemisphere (Shaun, I envy you right now...).
Fernando Comeron: "This amazing concentration of clusters, HII regions, supernova remnants, and extremely hot and luminous stars in a single region makes the Tarantula in the LMC a unique celestial object, unrivalled in our own Galaxy and other nearby galaxies!"

http://www.spaceref.com/news/viewpr.htm … ~*Symphony of colors*~

*I cannot pass this up. Image created by an amateur astronomer. Great text info too.

The Tarantula Nebula is the most vigorous star forming region known in the -local- Universe.

Astronomers believe that this smallish, irregular galaxy is currently going through a violent period in its life cycle. It is orbiting the Milky Way and has had several close encounters with it. It is believed that the interaction with the Milky Way has caused an episode of energetic star formation - part of which is visible as the Tarantula Nebula. The Tarantula is the largest stellar nursery we know in the local Universe. In fact if this enormous complex of stars, gas and dust were at the distance of the Orion Nebula it would be visible during the day and cover a quarter of the sky.

:band:

--Cindy

Palomar · 2004-12-16 15:40:28

http://www.universetoday.com/am/publish … 2004]Sooty Nebula

*Is "in" Cygnus, 5000 light years distance. Subaru telescope image.

The surface of the star in the center of the nebula sizzles at a temperature of forty two thousand degrees Kelvin, and shines fifty thousand times brighter than our Sun.

Says the star expelled its outer layers approximately 900 years ago. The resultant shell has expanded more than 100 times the extension of our Solar System.

--Cindy

Palomar · 2004-12-17 10:39:51

http://www.universetoday.com/am/publish … ry...being solved?

*What's the shape of the Helix Nebula? Cool article. :up:

it's actually two gaseous disks which are perpendicular to each other. One disk (inner) was expelled 6,600 years ago, and the other (outer) was fired off 12,000 years ago.

*The inner disk is expanding a bit faster than the outer disk. Neat-o. They're speculating the star which went supernova has a companion star; says there is evidence for that companion star via space-based x-ray observations.

Another surprise is that the dying star has expelled material into two surrounding disks rather than the one thought previously to be present. Each disk has a north-south pole, and material is being ejected along those axes. "We did not anticipate that the Helix has at least two axes of symmetry," O'Dell said. "We thought it had only one. This two-axis model allows us to understand the complex appearance of the nebula."

*Always new marvels in the universe, huh?

-*-

http://antwrp.gsfc.nasa.gov/apod/ap041216.html]Majestic arms of Galaxy NGC 7424

*Lovely.

--Cindy

GraemeSkinner · 2004-12-17 13:37:57

http://antwrp.gsfc.nasa.gov/apod/ap041216.html]Majestic arms of Galaxy NGC 7424
*Lovely.

That picture has definite WOW factor :up:

Graeme

Palomar · 2004-12-17 16:01:01

http://antwrp.gsfc.nasa.gov/apod/ap041216.html]Majestic arms of Galaxy NGC 7424
*Lovely.
That picture has definite WOW factor :up:

Graeme

*Doesn't it, though? Reminds me of a celestial octopus, splaying its gently curved tentacles outward.

---

And I just had a !~BOIIING~!! moment. :-\

Looking at that galaxy, imagining going there: Being pulled through the frame and onward towards that destination.

Yes, I've known what a light year is for decades now. And I've known of the tremendous distances involved for just as long. Since childhood. But it hit me *again*, all of it: Even if one could travel at the speed of light, it'd take 40 million years to reach this galaxy.

Utterly mind-boggling. Again.

--Cindy

GraemeSkinner · 2004-12-18 00:32:31

Strange I missed http://www.spaceflightnow.com/news/n041 … star/]this article quite interesting too.

Graeme

Shaun Barrett · 2004-12-18 19:01:49

Cindy:-

Yes, I've known what a light year is for decades now. And I've known of the tremendous distances involved for just as long. Since childhood. But it hit me *again*, all of it: Even if one could travel at the speed of light, it'd take 40 million years to reach this galaxy.
Utterly mind-boggling. Again.

You bet!
If you sit for a minute and just think about even the distance to the nearest star, I mean really think about it, the incredible void between individual stars can give you vertigo!
Trying to imagine the size of our own galaxy is, in my opinion, simply so far beyond human experience of distance that it can't be comprehended by the human brain. Oh sure, we can write down the numbers and bandy them about in a seemingly knowledgeable fashion, but a visceral understanding of what we're talking about is out of our reach, I think.

The same applies to the vast stretches of geological time we talk about so casually. I remember reading comments by a scientist (sorry, can't recall who it was) on this subject and he was trying to put it into perspective.
On a gelogical time-scale, we talk about the K-T extinction event, which ended the reign of the dinosaurs, as though it happened quite recently. And it's true that, compared to Earth's total history, 65 million years isn't all that long.
But if we go back to the earliest civilisations we know of, we're talking about roughly 6000 years ago. In itself, that's a difficult enough timespan to take in but we have to multiply that span by 10,000 before we get back to the Cretaceous period. Even if we go back to the dawn of modern man, perhaps 200,000 years ago, that's still only about 1/300th of the yawning temporal chasm that separates us from the Triceratops and the Tyrannosaur!

Cindy:-

Utterly mind-boggling. Again.

Never a truer word spoken!
I know we can 'talk the talk' but I really don't believe we can 'think the thought' - our "primitive ape-brains" just aren't equipped for the job.

Palomar · 2004-12-19 08:48:58

http://antwrp.gsfc.nasa.gov/apod/ap030127.html]Dark molecular cloud

http://antwrp.gsfc.nasa.gov/apod/ap0412 … ]Molecular Cloud Barnard 68

*Another dark molecular cloud. Not sure I've seen this image previously. These things are so cool.

-*-

http://antwrp.gsfc.nasa.gov/apod/ap041218.html]Agenor Linea on Europa

*Where has Astropix been hiding that image of Europa??
1000 km long x 5 km wide. Curiosity about its being "uniquely bright." Wondering about that reddish material. http://antwrp.gsfc.nasa.gov/apod/ap021101.html]This other Astropix article is of interest, pertaining to the reddish material (I've previously posted it in one of the Unmanned Probes threads).

--Cindy

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#26 2004-12-03 21:55:29

Re: New Discoveries *4* - ...Solar System, Deep Space, cont'd

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#37 2004-12-11 14:00:37

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#38 2004-12-11 14:11:54

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#39 2004-12-11 21:23:00

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#40 2004-12-13 03:26:45

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#41 2004-12-15 07:39:18

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#42 2004-12-15 13:19:09

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#43 2004-12-16 07:24:13

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#44 2004-12-16 15:40:28

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#45 2004-12-17 10:39:51

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#46 2004-12-17 13:37:57

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#47 2004-12-17 16:01:01

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#48 2004-12-18 00:32:31

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