Today, after entering other posts on other topics, I am now being not allowed to post here as reply #4, with a couple video links for this comet story.
Prior entries on others topics were successful, with no delays or errors.
My text tried twice, resulting in a browser claim of "not able to connect with www.marsroverblog.com" error.
You Tube selections for the 2013 passage of this comet. General information from a number of sources and individuals.
A close pass-by of Mars, possibly?
One of these links should work.
'Comet ISON C/2012 S1 Orbit'
'2013 Year of the Comets ISON , Lemmon , PANSTARRS (HD)'