This is a rotated, contrast-enhanced
crop from the narrow-angle Mars Global Surveyor photo strip available at
The pond we're looking at [white arrow] lies at the floor of
a crater centered near 23.5° W, 60° S. The
wider-angle context image M04-00605 (not shown) suggests a
second such pond a bit further off to the right and at least
several others in an adjacent crater. Older Viking coverage
also shows some darkenings at those floors but the
resolution isn't fine enough to see any
The dark-colored "floaters" within
this liquid body vary in size from about 66 meters down to
the limit of the image's resolution of about 4 meters per
Directly below I have provided a cropping
at the same scale except with an equalized histogram
(brightness values adjusted to provide a more even range
from black to white) and some added false color.
If this body is indeed a liquid, and it certainly gives every
appearance of one, we would need to come up with some idea
of what compounds could remain at that state at many tens of
degrees below zero Celsius and under a relative vacuum of
around 7 millibars. Water, if it's saturated with just the
right salts, could remain liquid down to around -63 C (-81.4
F) and yet wouldn't boil until it passed +10 C (+50 F).
That's not a bad temperature window, actually. Ammonia,
hydrogen sulfide, chlorine and sulphur dioxide are also
liquids at those sorts of temperatures under earth-normal
pressure, but at 7 millibars they would all vaporize. The
latter two come close, but they would each need an
additional 8 millibars or so of pressure.
The floaters all look fuzzy around their edges, which
might suggest they're covered with fine appendages --
branches perhaps. Further out from each floater we see
a paler haze which here and there seems to interconnect them.
Notice the arched distributions, especially that circular
grouping near bottom center.
Now one might argue that these blobs are nonliving but
dissolving slightly into the fluid, hence the blurs; but
that's quite a stretch and it seems difficult to imagine a
process like that which would be sustainable and repeatable
over the eons. My vote is that we're looking at a colony of
hundred-plus-foot-wide organisms that are either roughly
spherical like bushes or flattened like pancakes.
A couple of weeks ago some high school students discovered
in another MGS shot some extremely dark rocks sprinkled
against a much lighter backdrop. Maybe these "rocks" are
the same as the floaters we see in this liquid, and when the
liquid dries up they go to seed or whatever and then
disintegrate. These seeds then lie dormant in the soil until
another opportunity arises.