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Explanation needed: unknown objects orbiting our sun in NASA images

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  1. Sep 6, 2010 #1

    taylaron

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    Gold Member

    Greetings,
    I've stumbled upon some peculiar images of our sun that appear to have extremely large objects in orbit which don't appear to be planets.

    The images are from the following NASA database. Each image is taken every ~10 minutes.

    http://stereo-ssc.nascom.nasa.gov/browse/2010/01/27/behind/euvi/195/2048/index.shtml

    I'm seeking a rational explanation for these visual phenomenon. It cannot be Mercury since Mercury's orbit time is about 88 days and many images within an hour have these objects. I doubt it is optical error from the satellite because they are in different spots relative to the Sun. I'm also deterred from assuming it is an asteroid based on its extremely close proximity to the sun. Shouldn't they have vaporized by now?

    Regards,
    -Taylaron
     
  2. jcsd
  3. Sep 6, 2010 #2
    CMEs (coronal mass ejections) throw most of the ejected mass out of the solar system--or at least out into the realm of the planets. But some of the mass can end up in solar orbit.

    Of course, most of the non-ejected mass carried by the magnetic loops falls back into the sun over a period of minutes to hours. Maybe this is what you are seeing?
     
  4. Sep 6, 2010 #3
    There's a lot of images in that list, and the few I checked lacked any surprises. Could you be more specific ?

    FWIW, I've read that the SOHO observatory routinely spots sun-grazing and sun-impacting comets and asteroids.
     
  5. Sep 6, 2010 #4

    russ_watters

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    I see what appear to me to be hot pixels and dust, but no objects orbiting the sun in those pics. Recognize that those pics are taken in UV light, so it wouldn't be possible to pick up any objects in orbit of the sun unless they were emitting UV light at a similar intensity of the sun.
     
  6. Sep 6, 2010 #5

    taylaron

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    specific pictures:

    (small black dot right below the E in EUVI, in the corona) Requires full resolution viewing.
    http://stereo-ssc.nascom.nasa.gov/b...d/euvi/195/2048/20100127_000530_n4euB_195.jpg

    Some people have put together slideshows of these images. I figure showing you the slideshow would be easier than describing each picture individually. Each frame can be identified by the time stamp at the bottom.

    Here is one of the few links I could find that doesn't describe them as UFO's...
    http://www.youtube.com/watch?v=OGSywJGo9Qc&feature=related

    Can coronal mass ejections cause visualizations like these? There are so many of them...

    -Taylaron
     
  7. Sep 6, 2010 #6

    taylaron

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    I see. What about the possibility of UV light reflecting off the object(s)? Also, if the object is next to the sun from our perspective, wouldn't the far side of the object not be as luminous?
    Can hot pixels vary from frame to frame like this?

    I'm willing to accept any of the explanations I've heard thus far, I simply wanted some insight into what these few pixels may represent. Or whither or not these pixels are simply flaws in the camera, resulting in the wasted time of everyone who has posted on this thread...

    Thank you for your time.

    -Taylaron
     
  8. Sep 6, 2010 #7

    russ_watters

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    Pretty good - but the only way for it to be reflected off as bright as the sun would be using a slightly concave mirror to focus the sun's light toward the detector....a perfectly pointed flat mirror would result in a reflection almost as bright as the sun.

    In any case, the "object" you pointed out is, if anything, silhouetted. But that still makes it likely to be dust.
    Yes.
    Well, it is common fodder for people who see alien spacecraft in every photographic anomaly and debunking that kind of thing has some value.

    BTW, I'm not seeing anything on the video clip.
     
  9. Sep 7, 2010 #8
    I watched the video--once I turned the music down--and didn't see anything unusual. First, there is a lot of frame to frame variation due to video compression. If you want to do real analysis, get the original uncompressed files.

    I also saw some dust in the vicinity of SOHO. Remember that with optical systems, dust near the focal point can look quite large. SOHO is located in the Earth-Sun L1 point, which is inherently dusty. To give you some idea, go out on a clear, dark night--camping in the mountains is fine, or just a vacation there. Deserts also work, but are not as nice to visit during the day.

    If you look in the sky directly opposite the sun's location, you will see a diffuse glow. This is sunlight reflected from dust in or near the Earth-Sun L2 position. L1 is not quite as dusty, but close. (L4 and L5 contain more dust but spread over a larger area. You can't see those glows with the naked eye as the L4 and L5 points are much further away from Earth.) Oh, and you can't see L3 from Earth at all. ;-)

    As for the black spot, this looks to be a rat. ;-) That is the name given to cosmic ray hits on the camera sensor that are not in the plane of the sensor. They look black because the cosmic ray hit effectively shorts the CCD cells around the hit for a short period of time, so no photons are counted.

    To make a long lesson quite short, the remote sensing crowd in the space and intelligence communities have now had 50 years of collective experience with all sorts of fruit and other artifacts that can show up in radar and visual image data. I don't know of any university that has a Master's or PhD program specifically in this area, but I know a few Astrophysics professors who spent decades learning the tricks of the trade. (I worked on the design and development side of the industry, so my exposure is mostly from watching the experts tear into a design and look for potential error and failure sources.)
     
  10. Sep 7, 2010 #9

    taylaron

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    Wow, this information is certainly very helpful. I didn't realize space dust was such an issue in satellite optics; although it does make a great deal of sense come to think about it. The effect cosmic rays have on the camera sensor really is interesting. That would explain why that black dot is in many of the images when looked at in full resolution...

    Thanks everyone.

    -Taylaron
     
  11. Sep 9, 2010 #10
    Hmm. It is not a major problem unless you stick something in one of the Lagrange orbits. Since these are stable or semi-stable orbits, they have had billions of years to accumulate dust. The gegenshein is the best known example (and "shines" due to reflections by ice particles). However, you can see the dust in the (Earth-Moon) L4 and L5 orbits with a good telescope. Set the motor to follow the moon, but look 60 degrees away. Or track the stars and photograph the dust as trails.

    Also when I was with MITRE I worked on the GEODSS project which uses telescopes at several locations to track satellites in geosynchronous orbit. The Air Force also uses GEODSS to get a good idea of dust concentrations in geosynchronous orbit and elsewhere. Even when you can't track individual specks, it is possible to estimate the concentration from the hazing effect. (Compare a star photo through the dust, say L4 with a photo taken away from the moon's orbit.)

    If it is persistent over a period of minutes it is more likely a dead pixel, or dust on the sensor. Rats fade. Think of them as charging a CCD (charge coupled device) in the wrong direction. They fade quickly, but will often appear in several successive frames. (Depending on the refresh rate.)
     
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