The most noticeable observation of Mars in the last 2012 season has been the imagery of what is generally interpretated as a cloud of very high altitude, because it was projecting well beyond the terminator into the night. Those phenomena look to happen regularly and many have been found on past data (read for example my ISMO essay in CMO n°400). A new one has possibly been observed this year.
I have noticed this possible candidate first on images I have taken under average conditions during the night from 7 to 8th April 2014. This detail is far from being as proeminent as in the 2012 images, but the “protruding” aspect from the terminator is significant:
The detail looks to evoluate with time, as it passes above and beyond the terminator. The observation looks to have been confirmed now by images realized 20 days before by Darryl Milika and then Kevin ? ten days after. Each time the object is visible over the same zone, just like in 2012.
We must be careful here, because bright objects can appear proeminent on the limb, as they can “irradiate” onto the sky background. However, this one does not look that bright and the repeated imagery brings more confidence.
Moreover, the aspect is very similar to that of the 2012 cloud as it looked some ten days before its official discovery by Wayne Jaeschke. Some images had been done in France, for example by Yann Le Gall and Marc Delcroix. At the time the cloud was only a small bright point.
Now this one is found unfortunately on the evening side, that is is becoming less and less visible after opposition. On the other hand, we can now observe the Martian morning, where most of the events have been observed! This is even more interesting because Reiichi Konnaï, a Japanese observer also member of the ISMO advisory board, has just found an older occurence of the 2012 cloud but imaged in 2010 this time, by images from Bruce Kinglsey and Simon Kidd, confirming the importance of the location and the relative frequency of those phenomena.