Fireball over Mount St Helens?
On reviewing last night's images from the Volcanocam cameras, I noticed that one of the images appeared to show a bright circular object above Mount St Helens at 02:21am this morning.
Checking the archived images from last night revealed another image that was taken a five seconds later than the image I had downloaded.
Comparing the two showed that the object had moved between the two frames, making it likely it was something recorded by the camera, rather than thermal or other noise. (which is the cause of all the small hot-spots on all the nigh time images, which do not move locations).
A brief animation of the two images with the bright spot, together with an image from five minutes before and afterwards is available as an animated gif and a full sequence from sunset to sunrise is also available on my website at www.luscombe-carter.com.
I'm not sure what the bright spot is. It obviously appears to be circular, but this could be a result of overexposure causing a circular record on the CCD. A bright fireball would fit the bill, similar to the one that was seen in BC, Washington, Oregon and Idaho in February 2008. Although I haven't been able to find any record of anyone seeing anything like this last night.
Probably a much more likely explanation is an aircraft or helicopter with its landing lights turned on approaching the JRO Observatory where the cameras are located. Although I haven't noticed any similar occurance since the recent activity at Mount St Helens began in 2004.
Another possibility is a bright Iridium flare, although this seems unlikely and more to the point none were visible around this time from Mount St Helens.