High Altitude Triangular Cloud Report

Around 0130 UT 15 Feb 2004 at latitude 41 48 08 N, longitude 94 37 53 W I
observed a triangular white cloud about 1 to 2 degrees wide centered over
Omicron 1 & Omicron 2 Eridani. The sky was completely clear, except for this
anomalous cloud. I was observing from a very dark location about 10 minutes
after the end of astronomical twilight, and this cloud had a high enough
surface brightness that I am certain it was not being significantly illuminated
by terrestrial light sources.

The cloud had a diffuse edge, and had no discernable color other than white. I
was able to observe the cloud for nearly 40 minutes, during which time it
isotropically expanded and dimmed. The expanding cloud moved very slowly
relative to the background stars, so that right before it faded to invisibility
(40 minutes after I first saw it), it was only about 5 - 10 degrees southwest
of Omicron 1 & Omicron 2 Eridani. There was no detectable fluctuation in
brightness as is usually seen with isolated auroral clouds, only a slow dimming
as it expanded.

I have seen this phenomena twice befo once in the late 1990s (in June at
Jefferson, Iowa), and once in 1980 At Iowa State University's Erwin W. Fick
Observatory near Boone, Iowa. The former was a circular cloud, and the latter
was a cloud about 6 degrees long and about 1 degree wide.

Does anyone have an explanation for this phenomenon? Have any of you observed
similar events?

Thank you,

David Oesper
Ames, Iowa

"DaveOesper" wrote in message
...
Around 0130 UT 15 Feb 2004 at latitude 41 48 08 N, longitude 94 37 53 W I
observed a triangular white cloud about 1 to 2 degrees wide centered over
Omicron 1 & Omicron 2 Eridani. The sky was completely clear, except for
this
anomalous cloud. I was observing from a very dark location about 10
minutes
after the end of astronomical twilight, and this cloud had a high enough
surface brightness that I am certain it was not being significantly
illuminated
by terrestrial light sources.

The cloud had a diffuse edge, and had no discernable color other than
white. I
was able to observe the cloud for nearly 40 minutes, during which time it
isotropically expanded and dimmed. The expanding cloud moved very slowly
relative to the background stars, so that right before it faded to
invisibility
(40 minutes after I first saw it), it was only about 5 - 10 degrees
southwest
of Omicron 1 & Omicron 2 Eridani. There was no detectable fluctuation in
brightness as is usually seen with isolated auroral clouds, only a slow
dimming
as it expanded.

I have seen this phenomena twice befo once in the late 1990s (in June
at
Jefferson, Iowa), and once in 1980 At Iowa State University's Erwin W.
Fick
Observatory near Boone, Iowa. The former was a circular cloud, and the
latter
was a cloud about 6 degrees long and about 1 degree wide.

Does anyone have an explanation for this phenomenon? Have any of you
observed
similar events?

It sounds very much like a fuel dump (water dumps by the Shuttle and Space
station can also have similar appearance). When a satellite is launched, it
is a good practice to expel the fuel, to prevent a potential explosion.
Observers often report a triangle, or "trumpet" shaped cloud.
--
Stephen
Home Page: stephmon.com
Satellite Hunting: sathunt.com

"DaveOesper" wrote in message
...
Around 0130 UT 15 Feb 2004 at latitude 41 48 08 N, longitude 94 37 53 W I
observed a triangular white cloud about 1 to 2 degrees wide centered over
Omicron 1 & Omicron 2 Eridani. The sky was completely clear, except for
this
anomalous cloud. I was observing from a very dark location about 10
minutes
after the end of astronomical twilight, and this cloud had a high enough
surface brightness that I am certain it was not being significantly
illuminated
by terrestrial light sources.

The cloud had a diffuse edge, and had no discernable color other than
white. I
was able to observe the cloud for nearly 40 minutes, during which time it
isotropically expanded and dimmed. The expanding cloud moved very slowly
relative to the background stars, so that right before it faded to
invisibility
(40 minutes after I first saw it), it was only about 5 - 10 degrees
southwest
of Omicron 1 & Omicron 2 Eridani. There was no detectable fluctuation in
brightness as is usually seen with isolated auroral clouds, only a slow
dimming
as it expanded.

I have seen this phenomena twice befo once in the late 1990s (in June
at
Jefferson, Iowa), and once in 1980 At Iowa State University's Erwin W.
Fick
Observatory near Boone, Iowa. The former was a circular cloud, and the
latter
was a cloud about 6 degrees long and about 1 degree wide.

Does anyone have an explanation for this phenomenon? Have any of you
observed
similar events?

It sounds very much like a fuel dump (water dumps by the Shuttle and Space
station can also have similar appearance). When a satellite is launched, it
is a good practice to expel the fuel, to prevent a potential explosion.
Observers often report a triangle, or "trumpet" shaped cloud.
--
Stephen
Home Page: stephmon.com
Satellite Hunting: sathunt.com

"DaveOesper" wrote in message
...
Around 0130 UT 15 Feb 2004 at latitude 41 48 08 N, longitude 94 37 53 W I
observed a triangular white cloud about 1 to 2 degrees wide centered over
Omicron 1 & Omicron 2 Eridani.

Does anyone have an explanation for this phenomenon? Have any of you
observed
similar events?

You observed the exhaust from the firing of the 2nd stage of the IUS
(Inertial Upper Stage) that placed the DSP (Defense Support Program) 22
satellite into its geostationary orbit.

DSP 22 was launched on a Titan IV-B booster from Cape Canaveral on 2004 Feb
14 at 18:50 UTC. The IUS 2nd stage burn was scheduled to occur 6h 32m 56a
later, on Feb 05 at 01:22:56 UTC. Two other observations have been reported
via the SeeSat-L mailing list.

This was the third from final Titan IV-B launch, and the final use of an IUS
stage.

Spaceflight Now provided its usual excellent coverage of the launch:

http://www.spaceflightnow.com/titan/b39/status.html

Ted Molczan

"DaveOesper" wrote in message
...
Around 0130 UT 15 Feb 2004 at latitude 41 48 08 N, longitude 94 37 53 W I
observed a triangular white cloud about 1 to 2 degrees wide centered over
Omicron 1 & Omicron 2 Eridani.

Does anyone have an explanation for this phenomenon? Have any of you
observed
similar events?

You observed the exhaust from the firing of the 2nd stage of the IUS
(Inertial Upper Stage) that placed the DSP (Defense Support Program) 22
satellite into its geostationary orbit.

DSP 22 was launched on a Titan IV-B booster from Cape Canaveral on 2004 Feb
14 at 18:50 UTC. The IUS 2nd stage burn was scheduled to occur 6h 32m 56a
later, on Feb 05 at 01:22:56 UTC. Two other observations have been reported
via the SeeSat-L mailing list.

This was the third from final Titan IV-B launch, and the final use of an IUS
stage.

Spaceflight Now provided its usual excellent coverage of the launch:

http://www.spaceflightnow.com/titan/b39/status.html

Ted Molczan