Morning clouds and frost can sometimes settle in the broad, low plains of this region, making the giant Tharsis volcanoes Arsia Mons, Pavonis Mons
, and Ascraeus Mons, as well as nearby Olympus Mons, appear as dark spots above the bright plains.
Here we report on specific white clouds forming in the afternoon over Alba Patera, Olympus Mons (aka Nix Olympica), the Tharsis Montes (Ascraeus Mons, Pavonis Mons
and Arsia Mons) and Elysium Mons.
"Combined with the varying height of the volcanoes, we can say that Arsia Mons is the oldest, then Pavonis Mons
formed and finally Ascraeus Mons," said Mikael Beuthe of the Royal Observatory of Belgium and lead author of the paper.
Rock Instrumental Performance: Approaching Pavonis Mons
by Balloon (Utopia Planitia), The Flaming Lips.
Here we report on specific white clouds over Alba Patera, Olympus Mons ('Nix Olympica'), the Tharsis Montes (Ascraeus Mons, Pavonis Mons
and Arsia Mons) and Elysium Mons (Figures 14-16; and Part I, Figures 4F, 5).
In mid-November 2009, during early northern spring, observers detected bright clouds over the four great volcanoes of the Tharsis Bulge: Olympus Mons, Ascraeus Mons, Pavonis Mons
, and Arsia Mons.
The feature, identified as a cave or "skylight", near the Pavonis Mons
volcano was a hole, punched in the top of a hollow tube.
No separate condensate cloud over Pavonis Mons
was seen, but the western stroke of the 'W' crosses its summit.)
This month, users of modest-size telescopes are most likely to spy clouds over any or all of the four largest Tharsis volcanoes: Olympus Mons, Ascraeus Mons, Pavonis Mons
, and Arsia Mons.
Its three smaller neighbors--Ascraeus Mons, Pavonis Mons
, and Arsia Mons--each rise about 15 km above the surrounding plains and are arrayed in a line known as the Tharsis Ridge.