Arsia Mons Spiral Cloud
I'm not sure what you mean by "Spiral 'cloud' (not yet on the official site)", but the original captioned image was released yesterday by MSSS, which is what "ananova" based their enhanced image on.
See
Arsia Mons Spiral Cloud
MGS MOC Release No. MOC2-302, 11 February 2002
http://www.msss.com/mars_images/moc/1yearExtend/arsia/index.html
Alex R. Blackwell
University of Hawaii
