Tag: water

Data from Mars Reconnaissance Orbiter now suggests that a lake in a Martian crater had filled from groundwater coming up from below.

9:43 am

Data from Mars Reconnaissance Orbiter now suggests that a lake in a Martian crater had filled from groundwater coming up from below.

This is an important discovery, as it demonstrates that an underground water table had existed on Mars, at least at this location. With such a water table, it is possible for all kinds of interesting biological things to have taken place, underground.

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Messenger has found new and “compelling” evidence that there is water ice locked in the permanently shadowed craters of Mercury.

2:36 pm

Messenger has found new and “compelling” evidence that there is water ice locked in the permanently shadowed craters of Mercury.

On Monday I had spoken to one of the project scientists for this discovery, David Lawrence, in connection with an article I am doing for Astronomy on the evidence of water on the Moon. I knew the Mercury announcement was coming, and asked him for some details. Based on what he told me, it struck me that the evidence for water on Mercury is actually more conclusive than the evidence for the Moon. (In fact, inconclusive nature of the lunar data is the point of my Astronomy article, based on previous posts here and here on Behind The Black.

The more intriguing aspect of this discovery on Mercury, however, is the unknown dark material that covers and protects some of this water ice. That some scientists believe it might even be organic material deposited there by comets and asteroids is most interesting.

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The first results from Curiosity’s soil samples have come back.

1:38 pm

The first results from Curiosity’s soil samples have come back.

“Much of Mars is covered with dust, and we had an incomplete understanding of its mineralogy,” said David Bish, CheMin co-investigator with Indiana University in Bloomington. “We now know it is mineralogically similar to basaltic material, with significant amounts of feldspar, pyroxene and olivine, which was not unexpected. Roughly half the soil is non-crystalline material, such as volcanic glass or products from weathering of the glass. ”

Bish said, “So far, the materials Curiosity has analyzed are consistent with our initial ideas of the deposits in Gale Crater recording a transition through time from a wet to dry environment. The ancient rocks, such as the conglomerates, suggest flowing water, while the minerals in the younger soil are consistent with limited interaction with water.” [emphasis mine]

These results suggest that there has been very little water on the Martian surface for a very long time. They do not, however, mean that there is no water there now.

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Scientists have found the source of the water on the Moon and Mercury: the solar wind.

8:48 am

Scientists have found the source of the water on the Moon and Mercury: the solar wind. Key paragraph:

“We found that the ‘water’ component, the hydroxyl, in the lunar regolith is mostly from solar wind implantation of protons, which locally combined with oxygen to form hydroxyls that moved into the interior of glasses by impact melting,” said Zhang, the James R. O’Neil Collegiate Professor of Geological Sciences. “Lunar regolith is everywhere on the lunar surface, and glasses make up about half of lunar regolith. So our work shows that the ‘water’ component, the hydroxyl, is widespread in lunar materials, although not in the form of ice or liquid water that can easily be used in a future manned lunar base.” [emphasis mine]

Though this result would explain the detection of hydrogen on the lunar surface and would also mean that this hydrogen is far less useful for future colonists than previously hoped, it doesn’t eliminate the possibility that there is ice in the permanently shadowed craters near the lunar poles that came from other as yet unknown sources.

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Mars’ clay minerals might have been formed by volcanic processes, not standing liquid water as generally believed.

9:37 am

The uncertainty of science: Mars’ clay minerals might have been formed by volcanic processes, not standing liquid water as generally believed, according to a new study.

Data collected by orbiting spacecraft show Mars’ clay minerals may instead trace their origin to water-rich volcanic magma, similar to how clays formed on the Mururoa atoll in French Polynesia and in the Parana basin in Brazil. That process doesn’t need standing bodies of liquid water. “The infrared spectra we got in the lab (on Mururoa clays) using a reflected beam are astonishingly similar to that obtained on Mars by the orbiters,” lead researcher Alain Meunier, with the University of Poitiers in France, wrote in an email to Discovery News. The team also points out that some of the Mars meteorites recovered on Earth do not have a chemistry history that supports standing liquid water.

If correct, this alternative explanation would mean that Mars was not that wet in the past, and would have been far less likely of ever having sustained life.

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Water Ice in Shackleton Crater?

9:58 am

Ice in Shackleton?

New results from the radar instrument on Lunar Reconnaissance Orbiter (LRO) has found evidence of water-ice on the slopes of Shackleton Crater, located at the Moon’s south pole. The paper, published on Saturday in Geophysical Research Letters – Planets, suggested that about 5 to 10 percent of the weight of the material on the slopes of the crater is comprised of water ice, to depths of 6 to 10 feet.

The box on the upper left in the image to the right shows the data from a radar sweep of the crater taken on April 18, 2010, and compares that to five computer models. As you can see, the data here most closely matches the 5% ice model. Two other sweeps showed similar results.

The water-ice, if there, is not in slabs of ice, as sometimes portrayed in the press, but would be mixed into the Moon’s regolith, or “topsoil”, and would have to be processed out like ore to be useful. Or to quote the paper’s conclusion:

The fundamental conclusions made with high resolution, ground based radar of Shackleton remain unaltered — that no large-scale, meters thick ice deposits are evident within the crater. Rather, Mini-RF data are consistent with roughness effects or with a small percentage of water-ice deposits admixed into the uppermost 1-2 meters of silicate regolith within Shackleton, possibly accounting for the observations made by the Clementine bistatic experiment.

Several points:
» Read more

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Water on the Moon? The battle continues

2:18 pm

LEND data of lunar south pole

A little over a month ago I reported here on Behind the Black some recent results from the LEND instrument on Lunar Reconnaissance Orbiter (LRO) that had found significantly less water in the permanently shadowed craters at the lunar poles than previously thought. To quote again from that paper’s abstract, which I will henceforth refer to as Sanin, et al:

This means that all [permanently shadowed regions], except those in Shoemaker, Cabeus and Rozhdestvensky U craters, do not contain any significant amount of hydrogen in comparison with sunlit areas around them at the same latitude.

And from the paper’s conclusion:

[E]ven now the data is enough for definite conclusion that [permanently shadowed regions] at both poles are not reservoirs of large deposits of water ice.

Paul Spudis of the Lunar and Planetary Institute in Houston, Texas and one of the world’s top lunar scientists then commented as follows:

You neglect to mention yet another possibility — that this paper and its conclusions are seriously flawed in almost every respect. The veracity of the LRO collimated neutron data [produced by the LEND instrument] have been questioned on serious scientific grounds. Other data sets (spectral, radar) suggest significant amounts of water at both poles, billions of metric tons in total.

Spudis also discussed this scientific dispute at length on his own blog.

When I read Dr. Spudis’s comment I immediately emailed William Boynton of the Lunar and Planetary Laboratory at the University of Arizona, one of the authors of the Sanin et al paper, to get his reaction. Today he sent me the following detailed explanation, describing the basis of the controversy and why he believes the LEND data is valid.
» Read more

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Data of the tidal fluxes on Titan by the Cassini spacecraft now suggest that there is a liquid ocean below Titan’s icy crust.

5:09 pm

Data of the tidal fluxes on Titan by the Cassini spacecraft now suggest that there is a liquid ocean below Titan’s icy crust.

The team’s analyses suggest that the surface of the moon can rise and fall by up to 10 metres during each orbit, says Iess. That degree of warpage suggests that Titan’s interior is relatively deformable, the team reports today in Science1. Several models of the moon’s internal structure suggest such flexibility — including a model in which the moon is solid but soft and squishy throughout. But the researchers contend that the most likely model of Titan is one in which an icy shell dozens of kilometres thick floats atop a global ocean. The team’s findings, together with the results of previous studies, hint that Titan’s ocean may lie no more than 100 km below the moon’s surface.

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According to this article, the water-ice discovered at Shackleton Crater is insufficient for human settlement.

8:44 am

The uncertainty of science: According to this article, the water-ice discovery announced yesterday at Shackleton Crater is insufficient for human settlement.

The latest LRO data indicate “that water is not there … in a way that would facilitate human exploration,” says planetary scientist Maria Zuber, who led the team analyzing the data.

If the signatures the team saw in the soils on the crater floor do indicate water, how much water might there be? Roughly 100 gallons – enough to fill two or three residential rain barrels – spread over a surface of about 133 square miles. Leave the swim-suit at home. “This is not like Mars,” says Dr. Zuber, a professor at the Massachusetts Institute of Technology in Cambridge, in an interview. On the red planet, explorers would find thick layers of icy soil in many locations just by turning over a shovelful or two of topsoil. [emphasis mine]

This story seems to answer my question about Zuber’s participation in the water in Shackleton paper as well as the previous paper saying there is much less water on the Moon than previously believed. It also raises questions about the journalism work of many of the other stories published in the past few days, which heavily touted the possibility of water in Shackleton.

I intend to dig into this story a bit more. Stay tuned.

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New data from Lunar Reconnaissance Orbiter suggests that ice may make up as much as 22 percent of the surface material in Shackleton Crater, located on the moon’s south pole. The uncertainty of science: New data from Lunar Reconnaissance Orbiter suggests that ice may make up as much as 22 percent of the surface material in Shackleton Crater, located on the moon’s south pole.

11:01 am

The uncertainty of science: New data from Lunar Reconnaissance Orbiter suggests that ice may make up as much as 22 percent of the surface material in Shackleton Crater.

What I find most interesting about this result is that the team leader of this paper, Maria Zuber, was also one of the co-authors of the paper I wrote about two days ago that said there was no water in Shackleton Crater.

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The Moon: a desert after all?

10:10 am

LEND data of lunar south pole

The uncertainty of science: A new science paper, published Saturday in the Journal of Geophysical Research – Planets,, has found that there is much less water ice trapped in the permanently shadowed craters of the lunar poles than previously thought. From the abstract:

This means that all [permanently shadowed regions], except those in Shoemaker, Cabeus and Rozhdestvensky U craters, do not contain any significant amount of hydrogen in comparison with sunlit areas around them at the same latitude.

And from the paper’s conclusion:

[E]ven now the data is enough for definite conclusion that [permanently shadowed regions] at both poles are not reservoirs of large deposits of water ice.

» Read more

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Is it snowing microbes on Enceladus?

8:22 pm

Is it snowing microbes on Enceladus?

“More than 90 jets of all sizes near Enceladus’s south pole are spraying water vapor, icy particles, and organic compounds all over the place,” says Carolyn Porco, an award-winning planetary scientist and leader of the Imaging Science team for NASA’s Cassini spacecraft. “Cassini has flown several times now through this spray and has tasted it. And we have found that aside from water and organic material, there is salt in the icy particles. The salinity is the same as that of Earth’s oceans.”

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Scientists have found more evidence that the streaks on Martian hillsides that darken in warm weather are caused by melting groundwater flowing downhill.

8:36 am

Liquid water on Mars! Scientists have found more evidence that the streaks on Martian hillsides that darken in warm weather are caused by melting groundwater flowing downhill.

Last summer, the team pointing the HiRISE camera on the NASA Mars Reconnaissance Orbiter (MRO) dropped that bombshell: it had identified 7 confirmed and 12 likely sites that contained hundreds of narrow streaks on steep slopes inside crater walls. During warmer seasons, as temperatures rose as high as 27 degrees Celsius, the streaks darkened, and then faded again. Salts could allow brines to be liquid at these temperatures. Today at the Lunar and Planetary Science Conference in The Woodlands, Texas, the HiRISE team announced that it now has doubled it stash of streaks, with the identification of 15 confirmed and 23 likely sites, all in the mid-latitudes of the Southern Hemisphere.

Additional analysis of the spectrographic data also suggests that water could be the cause of the darkening.

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Mars Express has found more evidence that Mars once had oceans.

10:00 am

Mars Express has found more evidence that Mars once had oceans.

Two oceans have been proposed: 4 billion years ago, when warmer conditions prevailed, and also 3 billion years ago when subsurface ice melted following a large impact, creating outflow channels that drained the water into areas of low elevation.

“MARSIS penetrates deep into the ground, revealing the first 60–80 metres of the planet’s subsurface,” says Wlodek Kofman, leader of the radar team at IPAG. “Throughout all of this depth, we see the evidence for sedimentary material and ice.” The sediments revealed by MARSIS are areas of low radar reflectivity. Such sediments are typically low-density granular materials that have been eroded away by water and carried to their final destination.

This later ocean would however have been temporary. Within a million years or less, Dr Mouginot estimates, the water would have either frozen back in place and been preserved underground again, or turned into vapour and lifted gradually into the atmosphere. “I don’t think it could have stayed as an ocean long enough for life to form.”

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On the way to its winter haven, Opportunity found more evidence of water on Mars

4:27 pm

On the way to its winter haven, Opportunity found more evidence of liquid water that once flowed on Mars, specifically a geological vein that they think might be gypsum.

The vein examined most closely by Opportunity is about the width of a human thumb (0.4 to 0.8 inch, or 1 to 2 centimeters), 16 to 20 inches (40 to 50 centimeters) long, and protrudes slightly higher than the bedrock on either side of it. Observations by the durable rover reveal this vein and others like it within an apron surrounding a segment of the rim of Endeavour Crater. None like it were seen in the 20 miles (33 kilometers) of crater-pocked plains that Opportunity explored for 90 months before it reached Endeavour, nor in the higher ground of the rim.

According to what project scientist Steve Squyres said at a press conference today at the AGU meeting, “This is the single most significant piece of evidence that liquid water once flowed on Mars.”

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Mountains and buried ice on Mars

9:03 am

Mountains and buried ice on Mars.

New images from the high-resolution stereo camera on ESA’s Mars Express orbiter allow a closer inspection [of the Phlegra Montes mountain range] and show that almost every mountain is surrounded by ‘lobate debris aprons’ – curved features typically observed around plateaus and mountains at these latitudes. Previous studies have shown that this material appears to have moved down the mountain slopes over time, and looks similar to the debris found covering glaciers here on Earth.

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