Hi,

Here's an interesting post that recently made its way onto the UFOupdates
mailing list.

Enjoy!

>
> ----- Original Message -----
> From: <ufoupdates@...>
> To: <- UFO UpDates Subscribers 02 - :;>
> Sent: Friday, March 07, 2003 7:09 AM
> Subject: UFO UpDate: NASA/SOHO - How to Make Your Own UFO
>
>
> > Source: NASA/SOHO
> >
> > http://soho.nascom.nasa.gov/hotshots/2003_01_17/
> >
> >
> > Hot Shots from SOHO
> > How to Make Your Own UFO
> >
> > Caption: Ever since launch, there's been a number of people
> > who've claimed to have seen flying saucers and other esoteric
> > objects in SOHO images. Although some of these supposed pictures
> > of UFOs can seem quite intriguing, they have always turned out
> > to have a quite ordinary cause when examined by experienced SOHO
> > scientists. In recent days, we've been receiving so many
> > questions and claims that we'd like to set the record straight:
> > We've never seen anything that even suggests that there are UFOs
> > "out there".
> >
> > In the past we've been accused of "covering up" UFO evidence
> > when we present our explanations, and of "refusing to comment"
> > (or "clamming up") when we give up on somebody who won't accept
> > our explanations. While we don't expect to convince everybody,
> > we hope that this page (and links herein) can provide some
> > information for the curious who want to investigate the claims
> > on their own.
> >
> > Most commonly, UFO claims are due to perfectly natural flaws or
> > artifacts in our publicly available data. Quoting from one of
> > the replies sent by a SOHO scientist in response to a question
> > from the public:
> >
> > The most common sources of UFO claims are:
> >
> > * Planets: These always look very strange in LASCO images,
> > because they're so bright that the image blooms, and the CCD
> > pixels bleed along the readout rows. Some people try to claim
> > that they're flying saucers, based on their appearance. I've
> > also heard the claim that they're previously unknown Saturn-like
> > planets with rings around them. You can see what I'm talking
> > about on this SOHO Hot Shot page.
> >
> > * Cosmic rays: High energy particles from the solar wind,
> > and from the galaxy as a whole, whip around the SOHO spacecraft
> > and interact with the detectors. These produce spots and streaks
> > on the detector ranging from a single pixel, to large streaks
> > that span a large fraction of the image. These are most evident
> > during a solar storm, as can be seen on this Hot Shot page, but
> > are always present at some level. I know that some people have
> > claimed that they've seen spacecraft-looking things that seem to
> > be moving around, but which are obviously cosmic rays when
> > examined by an experienced observer. People see a cosmic ray at
> > one location in one image, and then another random cosmic ray
> > hit nearby in the next image, and claim they're both the same
> > thing moving between frames.
> >
> > Sometimes you'll see a cosmic ray seem to persist in the
> > web images for two or more frames. This is because we lose a
> > certain percentage of the data coming down from the spacecraft.
> > In LASCO such losses appear as square blocks in the image. The
> > software which puts the images up on the web will fill in these
> > blocks from the last good image, and if there's a cosmic ray in
> > that block from the previous image, it will appear in this image
> > as well. The way to check for this is to look at the raw data
> > files, which are also available on the web through the SOHO
> > catalog interface.
> >
> > * Software glitches: Occasionally we'll have some problems
> > with the software which produce the images for the web, and
> > strange artifacts will appear in the data. These glitches are
> > usually corrected within a few days. In fact, we had a couple of
> > instances of that recently.
> >
> > * Detector defects: There are defects which appear in the
> > cameras from time to time, sometimes temporary and sometimes
> > permanent. I remember seeing a web site which claimed that
> > strange lights were hovering over the lower left limb of the Sun
> > in EIT images, and thought to myself "You only just noticed
> > that?". Those defects have been around forever, and were seen in
> > the lab even before SOHO was launched.
> >
> > Debris: Small pieces of aging insulation on the outside of
> > the spacecraft, dust particles, micrometeorites etc can show up
> > in pictures. Visit the LASCO Debris Lists and Images page for
> > more details.
> >
> > On the general subject of UFO claims from SOHO images, one
> > should be aware that a lot of the supposed UFO pictures taken by
> > SOHO have been modified by the proponents. For example, looking
> > at the image that is distributed with the news release for the
> > upcoming UFO conference, it's obvious that the picture is taken
> > from a tiny number of pixels in the camera, and then passed
> > through some kind of smoothing filter to make it look like a
> > craft with rounded edges. They should at least have the courage
> > to show the actual data, and not something which has been
> > manipulated in Photoshop. In the example above, where the
> > original image was "revealed" through the timestamp, we have
> > shown how easy it can be to manipulate pictures into showing
> > UFO-like features.
> >
> > That all said, it should be noted that we do see objects moving
> > in SOHO images. Over 500 comets have been discovered in SOHO
> > images, most by amateurs using LASCO data which have been
> > downloaded from the web. That's more comets than from any other
> > observatory, either from the ground or in space. People are
> > looking for moving objects in these pictures all the time, and
> > are highly motivated to find them. None of them have ever turned
> > out to be anything other than comets.More about comets observed
> > by SOHO on this SOHO Hot Shot page.
> >
> > Credits: Newspaper article from Perth Sunday Times (Australia;
> > not affiliated with the UK newspaper The Sunday Times). Many
> > thanks to those who contributed their time & and resources to
> > this article. The EIT image credit is "SOHO/EIT (ESA & NASA).
> >
> >