The finding of water on Mars has started a debate on where it came from, how much Mars holds, where it lies, and how long it has lain. Now someone who has taken part in that debate for many years has weighed in.
The water on Mars debate
The inside wall of Newton crater on Mars shows an apparent seasonal flow of salty water down the wall. Photo: NASA/JPL/Caltech
The facts about water on Mars, incredible as they might seem, are not in dispute. Water has flowed on Mars, intermittently, for many years. The Mars Global Surveyor found the first signs: gully-like formations on crater walls. The Spirit rover sent back evidence of recent water flows, before its radio failed forever. Now comes clear evidence, from the Mars Reconnaissance Orbiter, that water flows down cliff faces and crater walls (those that face the Martian equator) every summer on Mars.
So: water on Mars exists. But where did it come from? Water cannot flow or stand constantly on the surface. Mars is far too cold for that (eighty degrees Fahrenheit below zero). So either it forced it way up from deep underground, or fell on Mars from above.
Either theory must explain these details:
- Water flowing on the ground, on the equatorial faces of high mountains and crater walls.
- Salty water.
- Stratified “topsoils.”
The conventional theory
Mr. Alex Morgan left this summary of the conventional theory on this comment space yesterday:
We know that there is water underneath the surface of Mars due to observations from orbiting spacecraft. This frozen water exists at depths very close to the surface (under a meter). We know this because landers (such as Phoenix) saw this water shortly after landing. It is unknown whether Mars has an active core or not, but the heat likely comes from impactors (asteroids, comets and the like), which provide energy to heat the ice. This heat can continue heating the ice for tens of thousands of years after the impact. This is known as a post-impact hydrothermal (PIH) system.
As this is practically universally accepted by the scientific community, there are a number of papers on the subject. Here are a few I would recommend:
Barnhart, C.J., Nimmo, F., Travis, B.J. Martian post-impact hydrothermal systems incorporating Freezing. doi:10.1016/j.icarus2010.01.013
Fassett, C.I., Head, J.W. Sequence and timing of conditions on early Mars. doi:10.1016/j.icarus.2010.11.014
Thorsos, I.E., Newsom, H.E., Davies, A.G. Availability of heat to drive hydrothermal systems in large martian impact craters. LPSC 2001 abstract
Wang, C., Manga, M., Wong, A. Floods on Mars released from groundwater by impact. doi: 10.1016/j.icarus.2004.12.003
Schulze-Makuch, D. et al. Exploration of hydrothermal targets on Mars. doi: 10.1016/j.icarus.2007.02.007
Note: the first of these Digital Object Identifiers does not resolve. The others do resolve. (Editor’s note: one wonders where Mr. Morgan got all these doi numbers. The most popular on-line publication that uses the doi system regularly is Wikipedia.)
The problem: those papers give evaluations only, not new facts. “We suggest,” says the second abstract. That’s what all the authors of those papers do: suggest.
More important than what they suggest is what they assume. They assume that Mars is very, very old. (Though this does not relate to the water on Mars debate, one paper assumes that Mars once had a strong magnetic field, and a “dynamo” to produce it. How that “dynamo” wound down, no one has ever explained.)
The Wang paper comes closest to the truth: impacts from above will heat whatever water is in the ground and make it flow. But the local flash floods on Mars did not come from groundwater alone. This again begs the question of where the groundwater came from. If it pushed up from a very deep aquifer, it would have frozen within a mile of the surface.
Finally: universal acceptance of any theory does not by itself make it true. The history of science is full of theories that scientists of one age all accepted, but scientists of the next age discarded.
The Hydroplate Theory
Walt Brown has an alternative: the Hydroplate Theory. What happened on Mars followed directly from what happened on earth about 4400 years ago. That event was the Global Flood.
The Flood was not simply an ocean suddenly overflowing its banks. It was a subcrustal ocean breaking through a crack in the crust. Through that crack, a tremendous jet of water shot up into the stratosphere and beyond. About one percent of the total weight of the earth, as water, rock and mud, escaped into space. Comets, asteroids, and meteoroids formed from this material.
The future asteroids (except for some “near earth objects” that never left the region of earth’s orbit around the sun) traveled out toward Mars and beyond. But many of those objects fell onto Mars. They delivered an amount of water about twice that of Lake Michigan. And, as meteoric impacts tend to do, these strikes threw large amounts of dirt into the thin air on Mars. This dirt mixed with the melted water and fell back as muddy rain. Eventually it dried—and stratified, because it sorted itself into layers, another thing that suspensions tend to do.
The debate challenge
Your editor shared with Brown Alex Morgan’s comments about water on Mars. Here is his reply:
Alex Morgan needs to provide calculations and a lot more information if he is claiming that impacts tens of thousands of years ago (or even ten years ago) explain the water that has flowed on Mars during the past few years. I don’t believe it.
Infrared images of Mars should show many cooling hot spots where impacts have occurred over the past tens of thousands of years. Where are those pictures?
Of course there is water ice just under Mars’ surface. Morgan and I agree on that. What is Morgan’s source for the water? How does he get drainage channels down the central peak of an impact crater? I have provided more than a dozen top-of-the-line references to support what I am saying. Science reported volume flow rates of 10 – 1,000 million cubic meters of water per second in order to carve some of the erosion channels on Mars. [“Carving them, researchers calculated, would take water gushing at 10 million to 1 billion cubic meters per second.” Richard A. Kerr, “An ‘Outrageous Hypothesis’ for Mars: Episodic Oceans,” Science, Vol. 259, 12 February 1993, p. 910.]
I am not surprised that some people, faced with the shocking fact that salt water has flowed within the past few years (if not during the last summer) have proposed that impacts tens of thousands of years ago could explain it. As Richard A. Kerr noted, “Outrageous Hypotheses” are having to be proposed. Nor am I surprised that Icarus might publish them.
If any of the four papers Morgan references go through the heat transfer calculations (and Morgan claims he understands and concurs with those calculations), I would be willing to read those papers and discuss them with him. He can also call me if he is willing to explain himself in more detail, but before he does, he should read what I have written on the subject. I can’t take the time to explain it to him. Nor am I impressed with someone who provides no details and says, “Just read certain papers or a book and you will understand why I am right and you are wrong.”
If Morgan has written a detailed explanation of whatever he is claiming, I would be happy to read it. He can forward copies to me.
When Morgan writes, “It is unknown whether Mars has an active core or not,” is he saying that maybe a hot core and volcanic eruptions on Mars melted water ice and explains the flows? If so, I would like him to show me where recent volcanic eruptions have occurred on Mars. Speculations on Mars having “an active core” should not enter the discussion. Let’s just deal with solid evidence.
Finally, if Morgan thinks he has a strong case and he is willing to state it in front of an audience, he can always accept my [long-standing telephone debate] offer.
The comment space will remain open to Alex Morgan, should he decide to make a counter-reply.
Featured image: a mosaic of Mars from the orbiters of Project Viking. Photo: NASA/Johnson Space Center. See here for guidelines for use.