Pinpoint of light surrounded by sphere of growing white mist just below Jupiter moving west to east seen in northern Nevada.

A pinpoint of light just below canis minor was slowly engulfed by a small white blurry puff.  I pointed it out to my husband.  We watched the object move in an accelerating straight line towards Regulus, just under Jupiter.  As it moved steadily across the sky, the puff of whitish mist around it steadily grew in circumference.  A tiny pinpoint of light could always be seen at the center of the growing "puff."  The object moved steadily across the sky toward Regulus (I whipped out my star tracker app to track it), it suddenly slowed and came to a stop just under Jupiter.  The puff continued to increase in circumference and dissipate.  The object then began to move slowly again towards Regulus.  As it approached Regulus it again slowed, stopped.  The tiny pinpoint of light could still be seen, the white puff around the object had now grown in size to such a circumference it could barely be seen.  The light then disappeard as the puff of white completely dissipated.
((ADDENDUM FROM MR. TED MOLCZAN, OF SEESAT-L))
Hello Peter,
The fuel dump from the Centaur stage of last night's Atlas V launch, was widely visible to the unaided eye from N. America. It began on Mar 13 at about 04:15 UTC, and was visible for about an hour.
Ed Cannon, a long-time member of SeeSat-L, described his sighting as follows:
http://satobs.org/seesat/Mar-2015/0143.html
The Centaur was on a high-elevation pass, that moved west to east across the southern sky. It climbed in altitude from about 2,500 km to more than 20,000 km, on its way to its apogee of about 70,000 km.
Best regards,
Ted Molczan
((END ADDENDUM))
We suspect the sighting is due to a fuel dump from an expended "Centaur" stage of an Atlas V missile launch.  We express our gratitude to Mr. Ted Molczan for the "heads up" on this incident.  We copy below his e-mail of March 13, 2015, about the incident.  PD