Diffuse disc seen from Alicante on 29 July

Allen Thomson (thomsona@netcom.com)
Sun, 13 Aug 1995 16:46:42 -0700

   Here's a "ufo" sighting from our recent vacation in Spain:

   On the night of 29 July 1995 (date and times local) my wife and I 
were walking on the ocean promenade beside the Melia hotel in Alicante 
(38.343N , 0.480W by my Garmin 40 GPS set). At 21:24 I noticed a small, 
bright, diffuse disc in the sky over the ocean seaward of a point of 
land up the coast from us.  I estimated its elevation with my hand, 
finding that the disc was just over the tip of my middle finger when my 
outstretched hand was held vertically at arm's length with the heel of 
the palm placed on the sealevel horizon: roughly 18 cm at 60 cm 
distance, or ~.3 radian or ~17-18 degrees. 

   The disc was circular, quite bright and pearly white, with no trace 
of color that we could see. I'd estimate its total brightness as equal 
to Venus at it's brightest; the sky was still fairly light, and no stars 
were visible.  The object was definitely extended rather than point-
like.  At a guess, it was three resolution-units across: perhaps 6 arc 
minutes, or a small but significant fraction of the width of the full 
moon.  No internal detail was noticeable, but there seemed to be some 
limb darkening. 

   Thinking that the object might be a balloon (many years ago I saw a 
Skyhook balloon just before sunset, and the appearance was somewhat 
similar), I stood against a light pole and observed its position 
relative to another pole.  No movement was perceptible over a period of 
a few minutes.  We then approached a Spanish family sitting on a bench 
on the promenade and asked if they knew what the object was.  They 
didn't, but said that they had been watching it for a while and it 
hadn't seemed to move. (Nobody around seemed to be more than mildly 
curious about the object) 

   We watched for a few more minutes until approximately 21:35, during 
which time the object didn't move or change appearance, and then 
returned to our room in the Melia. I got my compass from the suitcase, 
went onto the balcony, and tried to locate the object. By that time, 
21:42, at the approximate location of the object (as estimated from its 
azimuth relative to the point of land mentioned above and elevation 
measured by the hand-at-arms-length method) there was a bright star-like 
object redder, fainter, and more point-like than the object we had been 
watching.  The magnetic bearing read off the compass (which was likely 
affected to some extent by the steel structure of the hotel) was due 
east to within a couple of degrees.  My wife, who was helping me make 
this measurement, was doubtful that the object I was sighting on was the 
one seen earlier, due to its considerably different appearance. 

   So, any suggestions as to what this thing might have been?

   Possibilities that have come to mind are:

- A bright star or planet focused through a marine inversion layer
  (although SKYMAP doesn't indicate anything particularly promising at 
  that time and position)

- A high-altitude balloon which was apparently stationary due to
  some circumstance of geometry and winds

- A cloud released by some object in space such as a barium experiment
  or the venting/exhaust clouds associated with Centaur upper stages of 
  Titan IVs 

- "Them"  :-)