Explanation: What dark forms lurk in the mists of the Carina Nebula? These ominous figures are actually molecular clouds, knots of molecular gas and dust so thick they have become opaque. In comparison, however, these clouds are typically much less dense than Earth's atmosphere. Pictured above is part of the most detailed image of the Carina Nebula ever taken, a part where dark molecular clouds are particularly prominent. The image has recently been retaken and then re-colored based on light emitted by oxygen. The entire Carina Nebula spans over 300 light years and lies about 7,500 light-years away in the constellation of Carina. NGC 3372, known as the Great Nebula in Carina, is home to massive stars and changing nebula. Eta Carinae, the most energetic star in the nebula, was one of the brightest stars in the sky in the 1830s, but then faded dramatically. Wide-field annotated and zoomable versions of the larger image composite are also available.
Re: APOD: Dark Clouds of the Carina Nebula (2010 Sep 19)
Posted: Sun Sep 19, 2010 11:44 am
by León
Wide nebula 480 light years. The star Eta Carinae became the second brightest star in the mid-nineteenth century. Interestingly, the elements that comprise no carbon or elements heavier than oxygen, which can be part of the dust and / or molecular clouds and lit as protostars, additional sample dust recycling,
Re: APOD: Dark Clouds of the Carina Nebula (2010 Sep 19)
Re: APOD: Dark Clouds of the Carina Nebula (2010 Sep 19)
Posted: Sun Sep 19, 2010 5:36 pm
by drollere
"much less dense than earth's atmosphere" ... at what altitude? sea level? 50 miles?
Re: APOD: Dark Clouds of the Carina Nebula (2010 Sep 19)
Posted: Sun Sep 19, 2010 6:37 pm
by biddie67
such incredible chaos still available out there - not at all like our tidy little solar system
Re: APOD: Dark Clouds of the Carina Nebula (2010 Sep 19)
Posted: Sun Sep 19, 2010 8:54 pm
by Beyond
biddie67 wrote:such incredible chaos still available out there - not at all like our tidy little solar system
Tidy little solar system???? I guess you have forgotten all the craters on the other planets and moons in this "tidy" little solar system?
Granted there are no super novas, or even plain ole' novas, or even way below average black holes, but judgeing by all the pochmarks all over the place, all those meteors will just keep eating at you til you're gone. Hey! biddie67, you might be right after all. All those meteors are blasting everything away except for us(so far), so in a sense, they are kinda keeping this solar system tidy. What a strange place.
Re: APOD: Dark Clouds of the Carina Nebula (2010 Sep 19)
Posted: Wed Sep 22, 2010 1:38 am
by Just Asking
In the 19 Sept. 2010 APOD picture of the Carina Nebula there is a round or spherical object that is different from all the other dots or blobs in the picture. It is located in the lower right hand portion of the picture, just a bit above a mountain like structure protruding up from the bottom right of the picture. It is different from the other small blobs in that it is gray instead of brownish, and it is more spherical looking. It is almost planet looking, but of course it can not be a planet. What is it?
Re: APOD: Dark Clouds of the Carina Nebula (2010 Sep 19)
Posted: Wed Sep 22, 2010 4:04 am
by Sam
Just Asking wrote:In the 19 Sept. 2010 APOD picture of the Carina Nebula there is a round or spherical object that is different from all the other dots or blobs in the picture. It is located in the lower right hand portion of the picture, just a bit above a mountain like structure protruding up from the bottom right of the picture. It is different from the other small blobs in that it is gray instead of brownish, and it is more spherical looking. It is almost planet looking, but of course it can not be a planet. What is it?
My first thought was that it would be another one of those globules as seen elsewhere in the image, but it is indeed very spherical. On the Hubble release site there is an image that shows this gray sphere as a white sphere, thus, a star. Interesting that this single star got colored gray somehow! I didn't notice any other examples, but I didn't have too long to look.
Re: APOD: Dark Clouds of the Carina Nebula (2010 Sep 19)
Posted: Wed Sep 22, 2010 1:36 pm
by Chris Peterson
drollere wrote:"much less dense than earth's atmosphere" ... at what altitude? sea level? 50 miles?
Either? I think the intent of the statement was simply to provide some sense of the actual densities involved, not really a quantitative value. Regions with dust clouds like those in this nebula essentially qualify as pretty good vacuums. Significant extinctions are probably not reached until light travels many astronomical units in such a cloud.
Re: APOD: Dark Clouds of the Carina Nebula (2010 Sep 19)
Posted: Wed Sep 22, 2010 3:27 pm
by neufer
Chris Peterson wrote:
drollere wrote:"much less dense than earth's atmosphere" ... at what altitude? sea level? 50 miles?
Either? I think the intent of the statement was simply to provide some sense of the actual densities involved, not really a quantitative value. Regions with dust clouds like those in this nebula essentially qualify as pretty good vacuums. Significant extinctions are probably not reached until light travels many astronomical units in such a cloud.
http://en.wikipedia.org/wiki/Bok_globule wrote:
<<Bok globules or Thackeray's Globules are dark clouds of dense dust and gas in which star formation sometimes takes place. Bok globules are found within H II regions, and typically have a mass of about 2 to 50 solar masses (i.e., up to 1×1032 kg) contained within a region about a light year or so across (about 4.5 × 1047 m³). They contain molecular hydrogen (H2), carbon oxides and helium, and around 1% (by mass) of silicate dust.>>
Vacuum __________________ Pressure (Torr)
------------------------------------------------------------
Low vacuum _______________ 760 to 25
Medium vacuum ____________ 25 to 1×10−3
High vacuum _____________ 1×10−3 to 1×10−9 Ultra high vacuum _________ 1×10−9 to 1×10−12
Extremely high vacuum _______ <1×10−12
Bok globules _____________ 6×10−16 to 15×10−15 (at room temperature)
------------------------------------------------------------------------------------------------------------------------
# Low vacuum, also called rough vacuum or coarse vacuum, is vacuum that can be achieved or measured with rudimentary equipment such as a vacuum cleaner and a liquid column manometer.
# Medium vacuum is vacuum that can be achieved with a single pump, but the pressure is too low to measure with a liquid or mechanical manometer. It can be measured with a McLeod gauge, thermal gauge or a capacitive gauge.
# High vacuum is vacuum where the MFP of residual gases is longer than the size of the chamber or of the object under test. High vacuum usually requires multi-stage pumping and ion gauge measurement. Some texts differentiate between high vacuum and very high vacuum.
# Ultra high vacuum requires baking the chamber to remove trace gases, and other special procedures. British and German standards define ultra high vacuum as pressures below 10−6 Pa (~10−8 Torr).
<<Wake Shield Facility is an experimental science platform that was placed in low-earth orbit by the Space Shuttle. It is a 3.7 meter (12 ft) diameter, free-flying stainless steel disk. The WSF is deployed in the wake of the Space Shuttle at an orbital altitude of over 300 kilometers (186 mi), within the thermosphere, where the atmosphere is exceedingly tenuous. The forward edge of the WSF disk redirects atmospheric and other particles around the sides, leaving an "ultra-vacuum" in its wake. The resulting vacuum is used to study epitaxial film growth. Pre-flight calculations suggested that the pressure on the wake side could be decreased by some 6 orders of magnitude over the ambient (10−8 Torr) pressure in low earth orbit. Analysis of the pressure and temperature data gathered from the two flights concluded that the decrease was some 2 orders of magnitude or 4 orders of magnitude less than expected (i.e., from 10−10 to 10−12 Torr).
The WSF has flown into space three times, on board shuttle flights STS-60, STS-69 and STS-80. During STS-60, some hardware issues were experienced and as a result the WSF was only deployed at the end of the shuttle's robotic arm. During the later missions the WSF was deployed as a free-flying platform in the wake of the shuttle. These flights proved the vacuum wake concept, and realized the space epitaxy concept by growing the first-ever crystalline semiconductor thin films in the vacuum of space. These included gallium arsenide (GaAs) and aluminum gallium arsenide (AlGaAs) depositions. These experiments have been used to develop better photocells and thin films. Among the potential resulting applications are artificial retinas made from tiny ceramic detectors.>>
Tor Johnson (19 October 1903 – 12 May 1971) was a Swedish professional wrestler (billed as The Super Swedish Angel) and actor. He is perhaps best remembered for his roles in a number of B-movies, including police inspector turned zombie Daniel Clay in Plan 9 from Outer Space. Tor Johansson was born in Sweden, the son of Karl J. Johansson and Lovisa Petersson. He was a large man, weighing 400 pounds at his biggest. He had a full head of blond hair, but he shaved it to maintain an imposing, villainous appearance in wrestling and acting appearances. He began getting bit parts in movies upon his move to California - usually as the strongman or weightlifter - as early as 1934. His film career ended in the early 1960s after appearing in a string of poorly-rated movies. However, he continued to make appearances on television and made a number of commercials. Due to his work in early B-horror movies, Tor developed a small but enthusiastic cult following after his death in 1971. A number of Johnson's peers had commented that he was a very friendly man and easy to work with on movie sets. Valda Hansen, who worked with Johnson in the 1959 movie Night of the Ghouls said that "Tor was like a big sugar bun." Johnson befriended Bela Lugosi during the time both worked with director Edward D. Wood, Jr.
Re: APOD: Dark Clouds of the Carina Nebula (2010 Sep 19)
Posted: Wed Sep 22, 2010 5:40 pm
by Beyond
Hey Art, you got anything yet on plan 10 from outer space