Water Ice on Pluto Portents a Bright Future for Sailing the Solar System



From NASA, comments follow:

“New data from NASA’s New Horizons spacecraft point to more prevalent water ice on Pluto’s surface than previously thought.

This false-color image, derived from observations in infrared light by the Ralph/Linear Etalon Imaging Spectral Array (LEISA) instrument, shows where the spectral features of water ice are abundant on Pluto’s surface. It is based on two LEISA scans of Pluto obtained on July 14, 2015, from a range of about 67,000 miles (108,000 kilometers).

The scans, taken about 15 minutes apart, were stitched into a combined multispectral Pluto “data cube” covering the full hemisphere visible to New Horizons as it flew past Pluto. A data cube like this is a three-dimensional array in which an image of Pluto is formed at each LEISA-sensitive wavelength.

Water ice is Pluto’s crustal “bedrock,” the canvas on which its more volatile ices paint their seasonally changing patterns. Initial New Horizons maps of Pluto’s water ice bedrock compared LEISA spectra with a pure water ice template spectrum, resulting in the map at left.

A disadvantage of that technique is that water ice’s spectral signature is easily masked by methane ice, so that map was only sensitive to areas that were especially rich in water ice and/or depleted in methane. The much more sensitive method used on the right involves modeling the contributions of Pluto’s various ices all together. This method, too, has limitations in that it can only map ices included in the model, but the team is continually adding more data and improving the model.

The new map shows exposed water ice to be considerably more widespread across Pluto’s surface than was previously known — an important discovery. But despite its much greater sensitivity, the map still shows little or no water ice in the informally named places called Sputnik Planum (the left or western region of Pluto’s “heart”) and Lowell Regio (far north on the encounter hemisphere). This indicates that at least in these regions, Pluto’s icy bedrock is well hidden beneath a thick blanket of other ices such as methane, nitrogen and carbon monoxide.”

Notes: As the article observes, this is a significant finding, but not just for the scientific value alone. We are increasingly discovering that although only one planet in our solar system features standing water throughout its year, the entire system is fairly well blanketed in water ice deposits which range from Mercury to Pluto and beyond. And while it might beggar the imagination to see how ice at Pluto could be of any practical use given the extreme distance and deep, deep cold on that far away world, it is still an indication of just how resource rich our neighborhood really is.

The reason why this matters is intimately tied to the advances in reusable rocketry being driven by SpaceX and Blue Origin. The various destinations in space we might want to visit, or more importantly, settle one day, can all be considered as being connected by the energy required to reach them.

To the extent automated resource extraction and storage is developed by companies such as Shackleton Energy, Deep Space Industries and Planetary Resources, many of those points within the range of effective solar power can eventually be joined into a robust transportation hub powered by rocket engines only marginally more sophisticated than we are using today.

Would advanced propulsion options such as thermal fusion powered “torch ships” be nice to have? Of course they would, and to do much of anything past the asteroid belt on a human scale, some form of nuclear energy is almost certainly a requirement, even if it is just to keep the hardware from locking up and the wetware from freezing to death. But even torch ships would still need reaction mass, which is where all that water comes in.


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1 Comment on "Water Ice on Pluto Portents a Bright Future for Sailing the Solar System"

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  1. PK Sink says:

    Excellent article. Bring on the nukes!

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