Martian gullies not formed by water flow

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The uncertainty of science: Spectroscopy of many of the gullies on Mars strongly suggests that water had nothing to do with their formation, even though these gullies resemble closely similar gullies on Earth that were carved by flowing water..

Color coding in light blue corresponds to surface composition of unaltered mafic material, of volcanic origin. Mafic material from the crater rim is carved and transported downslope along the gully channels. No hydrated minerals are observed within the gullies, in the data from CRISM, indicating limited interaction or no interaction of the mafic material with liquid water. These findings and related observations at about 100 other gully sites on Mars suggest that a mechanism not requiring liquid water may be responsible for carving these gullies on Mars. (Gullies on Mars are a different type of feature than seasonal dark streaks called recurring slope lineae or RSL; water in the form of hydrated salt has been identified at RSL sites.) [emphasis mine]

In other words, these gullies were formed by flowing lava, not water. Considering Mars’s lower gravity, one third that of Earth’s, we should not be surprised if lava is capable of doing things there that it is not generally capable of doing on Earth. In fact, we should remind ourselves constantly that Mars is an alien planet, and that conditions there are different enough to make any predictions based on our knowledge of Earth very unreliable.

More details here.



  • Alex

    Off-topic: Mr. Zimmerman, do know something about a planned Russian mission to Jupiter’s moon Ganymede?

  • Alex: As I cannot speak Russian I can’t really comment on the video at the link. However, Anatoly Zak gives these details at his website,,

    In the waning days of 2013, the Russian government allocated 50 million rubles ($1.52 million) for the development of a technical proposal to land a probe on the surface of the Jovian moon Ganymede. According to the federal tender announced on Dec. 27, 2013, developers should submit their bids for the project by the end of January and the Russian space agency, Roskosmos, will award a contract on Feb. 6, 2014. The technical proposal for the mission known as Laplas-P have to be ready by Nov. 25, 2015. A dual mission would feature an orbiter and a lander launched by two separate rockets toward Jupiter. After reaching a vicinity of the giant planet, one probe will orbit its Moon Ganymede, while another would make the first ever landing on its surface.

    Unfortunately, he posts no further information, so I do not know if the contract was ever awarded.

  • Alex

    Mr. Zimmerman: Thanks. My command in Russian language is also very limited, but automatic translation of sub-title helps a little bit. They are talking much about this future mission to Ganymede, but I am wondering about hardware that is shown in report. I am not sure. Did they already built some hardware elements or is this ill-fated “Fobos-Grunt” probe, which shall deliver major components for Laplace probe as Mr. Zak wrote. Nevertheless, I cannot imagine that there is enough money in Russia to realize such an ambitious project.

  • Alex: I suspect you are right. If you look at all their proposed interplanetary unmanned missions listed on Zak’s website, you will see that all of them are in the same situation as this Ganymede mission, proposed a few years ago but as far as I can tell, never implemented. They have great ambitions, but no money to carry them out.

  • Alex

    Mr. Zimmerman: It so sad, they have ambitions, good ideas, deep knowledge and experiences and also some interesting technologies, but no money for required high level quality management and systems engineering. Remember, a few days before Russia launched Fobos-Grunt some years ago, technicians rewired some electrical connections of the probe, which was already placed atop the launcher (if I remember correctly), because a design error becomes known at last moment. Fobos-Grunt was also significantly underfinanced.

    I think, best what Russia can do at present in unmanned missions scenario is to cooperate with ESA – as already happens in case of Mars – by delivering launcher (Proton) and some probe elements as experiments or propulsion.

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