Welcome to The Deep science and technology column where we cover topics from the deep sea to deep space and beyond.
Water. When you live on an island, you’re surrounded by it and you tend to take it for granted. But there have been years when more people drowned than died in car wrecks here on Guam and I have always maintained that all beaches should have signs posted on them that say, “Mama Ocean does not forgive.”
We all must have water, we’re walking bags of the stuff and water has long been THE limiting factor of space exploration. It has for years cost about $10,000 a pound to put anything in low Earth orbit (LEO). You can quickly figure how much it would cost to put you in orbit.
But the figures quoted by the Russians to put tourists into LEO are in the multiple millions. Why? Because you have to eat in space, and most importantly you must drink and water weighs eight pounds a gallon. Every human on Earth consumes roughly five gallons of water every day. No, you don’t drink that much, but you water your lawn, eat meat from animals that drank water, eat fruits and vegetables that had to have water to grow and you go to the bathroom.
Although the bathrooms in space are different, space exploration and most importantly colonization, requires those five gallons of water every single day for every single person on the trip. Let’s see, that’s $80,000 for every gallon of water boosted into space and $400,000 for one day’s water ration for everybody involved. No wonder the Russians want all that money!!
That’s why the new water reclamation system on the International Space Station is so important and why scientists have been SO interested in trying to locate water on the Moon. If you can find water where you’re going, you don’t have to take so much with you.
As I’ve mentioned before, the Moon has a very harsh environment. It gets up to +250 degrees in the daytime and to –250 degrees at night. If you make your colonies underground, the average temperature is zero, which helps things out as far as easily making an Earth-normal environment, but doesn’t help you at all with the water requirements.
Now most people think that the Earth is the only place in the solar system with water, but that’s not true. Water is made from two elements, oxygen and hydrogen. Oxygen is fairly common in the solar system although its state as a free gas is found only on Earth because oxygen combines with almost everything and free oxygen has to be continually generated.
Hydrogen is THE most common element in the universe, not just the solar system. Probably somewhere between 98 and 99 percent of ALL the atoms in the universe are hydrogen which should give you some idea of how rare the rest of the elements truly are.
Water, it turns out is very common in our solar system, but virtually all water exists in the form of ice. And not just ice-as-we-know-it. Water is a very malleable molecule and there are at least 15 forms of solid water; some of them are not ice at all, but what we would call rocks. Earth is one of the few places in the solar system (but not the only one) that has the right temperatures to support lots of liquid water.
The Moon has no atmosphere and that 500-degree temperature range mentioned earlier virtually guarantees that when the Sun shines on the lunar surface, the +250 degree heat boils all the water off into space. The Moon is as dry as . . . well, anywhere where there is NO water. And despite the old ‘dark side of the Moon’ legend, the Sun does shine everywhere on the Moon. Well, almost everywhere.
The Moon rotates virtually straight up and that means that the area around both poles would be strange worlds indeed. The Earth rotates tilted and that means that the north pole gets sunlight half the year and darkness half the year. Ditto the south pole.
If you’re a billiard ball and you spin straight up and down, you’d see the Sun endlessly circle your horizon at each pole; but the Moon is not a billiard ball. It’s a big hunk of rock that’s been battered by other rocks for 4 or 5 billion years. One of the largest craters in the solar system is located at the Moon’s south pole.
Hmmmm . . . . big deep hole . . . that would be a place where literally, the Sun don’t shine. And if the Sun never shines there and that big deep hole happened to be made by a comet (read ‘great big iceberg’) then at the bottom of that hole, there could be . . . . water ice.
And it’s apparently true. Three different spacecraft have independently confirmed the presence of water on the Moon. Not only is there water at the poles, there are hydroxyl ions over the entire surface. Scientist still don’t know how those survive the heat of the Sun, but ice on the Moon means that you don’t have to take all your water with you at $400,000 per human per day. Even recycling can’t keep the cost down that much. Water on the Moon makes lunar colonization possible.
But what about beyond? You have to take your water with you when you go to the Moon, but the trip would last, at most two days. If you want to explore further; say travel to Mars, you’re looking at a six-month journey minimum. Go ahead; figure out how much that costs at $400,000 per human per day. Of course, recycling would be the norm, and we know how to do it, but what happens once you get to Mars and want to settle there?
I’ve always been amused by the frequent stories about how we’ve recently discovered that there’s WATER on Mars. We’ve known there’s water on Mars since at least the mid-1800’s. Mars has ice caps, and the one at the north pole is made mostly of water ice. The one at the south pole is made mostly of frozen carbon dioxide or dry ice which should make you readers with experience with dry ice realize just how cold it is on Mars.
But as near as we could tell, water on Mars was basically confined to the polar regions which severely limits the location of your colony. Mars does spin tilted and has definite seasons. Living near the north pole so you could harvest the water introduces a whole new world of risks.
But we know more about the surface of Mars than we do about the surface of the Earth because we’ve put several increasingly sophisticated satellites in orbit around the Red Planet. (And why do we know more about Mars than Earth? Most of the land on Earth is covered by that liquid water stuff and orbiting satellites can’t see it!)
These satellites have been orbiting Mars for years and comparing current data with the old pictures has revealed some interesting things. In a report in the journal Science, NASA says that its Mars Reconnaissance Orbiter has spotted ice in the bottom of five new Martian craters that were made by meteor impacts. And these craters aren’t at the poles; they’re in the middle latitudes. And they’re small and shallow, which means the water isn’t very deep below the surface.
Above: A fresh crater on Mars photographed on Oct. 18, 2008, and again on Jan. 14, 2009, by Mars Reconnaissance Orbiter’s HiRISE camera. The crater is about 15 feet wide and 4 feet deep.
So far, the MRO camera team has found bright ice exposed at five Martian sites with new craters that one and half to eight feet deep. None of the craters existed in earlier images of the same sites. The bright patches of exposed ice darkened within weeks as the ice vaporized into the thin Martian atmosphere.
Right: The patch of ice exposed at this late-2008 crater was large enough for the orbiter’s spectrometers to take readings and confirm that it is water.
An image taken by the MRO on 10 August 2008, showed a new crater that appeared after an image of the same ground was taken 67 days earlier. The opportunity to study such a fresh impact site prompted a look by the orbiter’s higher resolution camera on 12 September 2009, confirming a cluster of small craters.
The bright material at that site didn’t cover enough area for the MRO’s spectrometer to determine what it was made from. But the team quickly discovered another crater with a much larger area of bright material.
Above: This map shows five locations where fresh impact craters have excavated water ice from just beneath the surface of Mars (sites 1 through 5) and the Viking Lander 2 landing site (VL2), in the context of color coding to indicate estimated depth to ice.
The ice exposed by these fresh impacts suggests that NASA’s Viking Lander 2, digging into mid-latitude Mars in 1976, might have struck ice if it had dug only 4 inches deeper. The Viking 2 mission, which consisted of an orbiter and a lander, was launched in September 1975 and became one of the first two space probes to land successfully on the Martian surface. The Viking 1 and 2 landers also conducted on-the-spot biological tests for life on another planet. The results of some of those tests have never been adequately explained.
What if the Viking 2 arm had dug that extra four inches and revealed unmistakable evidence that there is life on Mars? Would we be there already? Probably. But we’ll get there eventually, and water, water everywhere will certainly help us make the trip!