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Water on Mars:

Please understand that the image studied underneath is just one example to illustrate a point. There are many other evidence leading to the same point: liquid water is still present on Mars nowadays.


The Mars Orbiter Camera (MOC) used on the Mars Global Surveyor satellite orbiting Mars has generated huge quantities of new Mars pictures. In year 2000, more than 60.000 of such images have been made available to researchers. In the beginning of 2001, more than 10.000 images have already been added. I have browsed only a very small portion of these images so far.

The photograph:

(1) a severely downsized version of the full original image.

(2) the lower region shown at the bottom of 1.

(1) original sized extract of the lower region shown on 2.


MOC picture from MGS


MOC picture from MGS


MOC picture from MGS

What NASA says:

Liquid water on the surface of Mars? Today, Mars is a cold, arid world. The driest deserts of Earth have many factors of ten more water than the surface environment of Mars. However, Mariner 9 and Viking in the 1970s showed abundant evidence that Mars once had channels and valleys carved by liquid water. These earlier missions, however, found only equivocal evidence of places where liquid water might have ponded to form lakes, seas, or even oceans.

MOC image 7707 (above) shows a portion of the wall and floor of an ancient impact crater in the southern cratered terrain of Noachis Terra. The MOC image reveals v-shaped depressions on the crater wall that are characteristic of water seepage from an underground layer that is exposed in the crater walls. The image also shows a smooth, dark surface on the crater floor that might be interpreted as the remains of a pond or lake. There are two types of dark surfaces on the floor of this 50 kilometer (31 miles) diameter crater, located at 65░S, 15░W. One dark surface shows a rippled texture and is known from Viking images to be a field of windblown dunes. The other is a relatively smooth surface with "islands" of bright material within it. The boundary between the dark floor materials and the lighter materials of the crater wall suggests, by the formation of bays and peninsulas, a "ponding" relationship.

There are four general hypotheses that might explain the "pond":

  1. Water seeped out of a layer in the crater wall, ran downslope, and ponded on the crater floor. This water would have eventually dried up, leaving a dark surface of sand similar to the material that comprises the dunes.
  2. The meteorite impact that formed the crater created cracks in the Martian crust beneath the crater. Eventually, dark (basaltic) lava came up through these cracks and "ponded" on the crater floor (this kind of process is not unusual and is known to have created the "mare" on the Moon). Heat from the magma and lava melted ground ice which then seeped as liquid water from a layer high in the crater wall.
  3. The seepage features are not related to the "ponding" feature. The "ponding" feature is actually coarse sand and/or gravel related to deflation of the crater floor and creation of the large field of dark sand dunes.
  4. None of the above are correct, and the features cannot be explained without additional information.


  1. is obviously incorrect: the global image obviously shows a valley system leading to the pond. If water have seeped from the crater wall, it would have filled the existing depression, but this valley feature could not have been created.
  2. for exactly the same reason as I, the explanation II is also wrong. Basaltic ponds indeed formed this way on the moon, and clearly the valley feature we have here has never appeared in company of basaltic ponds on the moon. And the debate is not over about the basaltic ponding on the moon: they are most likely not created by meteoritic impact, but by ancient magmatic convection. This pond is not at the feet of a volcano but at the feet of a meteoritic impact crater. Moreover, II is a confused explanation where water is added to the lava explanation with no reason. It just shows the embarrassment of the interpreter who cannot get the idea of liquid water out of the picture. In psychology, this is how you can detect a lie: two different explanations in a situation which in the end requires only one explanation. When someone is unsure, he will tend to add one poor explanation to the other because unconsciously he feels that to dismiss the truth you need to accumulate a high number of opposite reasons.
  3. is unclear. We have a very good continuity between the seepage and the pond feature. If the seepage was water and seeped on dark sand, we would not get this continuity. We would observe some kind of "delta" feature, where the seeping liquid water would be absorbed in the soil.
  4. is correct in the sense that indeed I, II, III are incorrect. But IV is not letting the cat out of the box. This is why I issue a (V)
  5. This is a drying lake. A large valley brought liquid water into the depression at the feet of a crater wall. The wall itself is damaged by water erosion, probably first by ice then later by liquid water. The lake has since dramatically dried up, but it is still there. Rocky islands clearly emerge from the water. On the steep crater wall side, the shoreline is absolutely well defined: water stops at the feet of the crater wall. On the other side, the slope is gentle, the contour of the lake is not so well defined. This is the side were the water is low, thus the lighter color.

As NASA says, the image shows a smooth, dark surface on the crater floor that "might be interpreted as the remains of a pond or lake". This is actually by far the simplest interpretation. When NASA says that the side near the crater wall is "a relatively smooth surface with "islands" of bright material within it", we have an understatement: it indeed absolutely smooth, it is the liquid water surface of the lake.

The reason that forces NASA to reject the idea that we see a liquid water lake is based on the notion that no liquid water can exist on Mars, due to the low temperature and low atmospheric pressure.

These reasons are not correct:

  1. this sector is at the bottom of Valles Marinensis, well under the average Mars surface level. The atmospheric pressure and the temperature is higher than average in this sector.
  2. the pressure and temperature was much higher in the past. It has decreased, but there still are remains of liquid water. Not all of it has gone.
  3. the ground in this depression is probably saturated with water. The underground temperature might be over average for various reasons, such as heating by sun reflection on the high albedo crater wall, geothermal activity, underground tectonic stress, concentrated biological activity etc.
  4. the water in this depression is the remain of a larger lake, thus saturated with various salts: the freezing temperature has then a very different value than the 0░C of clear water.
  5. the temperature measurements made by Viking in 1977 is the air temperature at more than 1 meter above the ground, and not the ground temperature.
  6. just as Viking "detected no organic material on Mars" which is to the common sense, impossible since organic material is found in any other place in the universe (*), the air pressure and temperature measurement might be simply wrong.

(*) The mass spectrometer supposed to have proven that there is no organic material on Mars has been tested again afterwards on Earth, and we have learned from this cross validation test that ... there is no organic material on Earth either!

New conclusion:

NASA via JPL and MSS has already stated that liquid water has almost certainly been abundant on Mars in the past. The images released my MSSS were rightfully shown as evidence.

The MSSS statement that "the driest deserts of Earth have many factors of ten more water than the surface environment of Mars" must be revised: it depends on the location studied, it is not so in zones of water seepage and water remains. Mars might have huge desert and dried up sectors, but not the entire surface of the planet matches this description.

Whereas I agree that Mariner 9 and Viking in the 1970s did provide "only equivocal evidence" of places where liquid water might have ponded to form lakes, seas, or even oceans, the latest images from MOC in 2000 and 2001 clearly show sectors where liquid water exist, even as lakes, in a manner that is not equivocal anymore.

What we have here is one among many other such images where the only reasonable hypothesis is that they are the evidence that lakes of liquid water still exist on low altitude sectors and, or, privileged heated up sectors of the planet.

We therefore have one other piece of the growing gathering of evidence that Mars is not at all the dead planet shown to their large audience to the mass media. In addition to the evidence on this photograph we now obviously have enough cross-evidence that Mars can and does harbor life, today.

Copyright notice:

In compliance with the MSSS image use:

"All Mars Orbiter Camera images are used courtesy of Malin Space Science Systems. Pursuant to the Image Use Policy , all original imaging credit is given to NASA/JPL/Malin Space Science Systems."


April 22, 2004 - Another lake on Mars:

The science team of the THEMIS instrument aboard Odyssey used to detect traces of past water, is annoyed with a new image which "is causing us considerable difficulty due to the presence of a structure that resembles a lake located in the center of the crater" on one of their images, published on April 22, 2004 on their website at http://themis.la.asu.edu/zoom-20040422a.html

The image can be downloaded there or seen as extract below:

Dark features at the bottom of Valles Marineris, ESA, February 2004:

ESA comment: "The data is flooding in too fast to make sense of some mysterious features, such as a dark splotch in Mars's grand canyon and along some valleys, he said. They may be sediments that OMEGA will be able to identify."

Image number: SEMBY9474OD

Caption: Reull Vallis - HRSC image 15 January 2004

Credits: ESA/DLR/FU Berlin (G. Neukum)

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This page was last updated on April 24, 2004.