5 times more water on the moon

Permanently dark craters on the moon may raise hopes for settlement on the moon * Evidence of huge reservoirs of frozen water has been discovered at the poles of the moon * Human colonies could use them for drinking and producing oxygen

1.4.2003

By: Avi Blizovsky

Right: the division of the moon into geological components. about a billion tons of water; Left: The distribution of ice at the North Pole of the Moon

The moon may contain 5 times more water than previously thought, US scientists claim in an article published in the journal Nature. They doubled the estimate of the area of ​​the moon that sunlight never reaches. This is encouraging news for those in favor of establishing a human colony on the moon.
Any ice that accumulated in these areas, near the lunar poles millions of years ago may still be frozen there, explains Ben Bussey from the University of Hawaii who studied the issue.
A colony that will use water from the lunar reservoir will revive the US space program and its inhabitants may mine precious minerals. The water can also be split into hydrogen and oxygen to be used for rocket fuel.
The American spacecraft Lunar Prospector discovered signs of a huge amount of ice, perhaps hundreds of millions of tons in 1998 in permanently shadowed craters at the lunar poles. This finding now seems certain when the existence of an ice surface on the bottom of a deep crater in the South Pole was also confirmed, as first discovered by the Clementine spacecraft in 1996.
Bossi's group proposes a hypothesis according to which there may be about a billion tons of water ice on the moon.

The average temperature on the surface of the moon is minus 23 degrees Celsius. The surface heats up only in direct sunlight, however in areas that are always shaded the temperature never rises above 230 degrees. Water that reaches the moon from crashing comets and meteorites early in the moon's history and this ice can remain frozen ever since.
Since the Moon rotates on its axis almost perpendicular to the plane of the Earth's orbit around the Sun, the sunlight at the poles almost touch steeply and create long shadows. Therefore, the bottom of some craters near the poles always remain in the dark.
Bossi's team calculated the area of ​​the bottoms of the craters that always remain in the shade even when the seasons change. This is not easy because we do not have a complete and detailed map of the surface of the moon, therefore the researchers estimate the desired area through the study of several typical craters of several sizes at different latitudes.
They found that craters between one and 20 kilometers in diameter create about 7,500 square kilometers of permanent shadow near the North Pole and about 6,500 square kilometers around the South Pole area. And this is only the lower limit - the discovery of larger or more complex craters can add space to the permanently shaded area.
Previous estimates were 2,650 to 5,100 square kilometers of shadow craters around the North and South Poles respectively.
to the article in Nature

The dark side of the moon will provide water for the astronauts on the way
By Lior Kodner

Since the landing of the first man on the moon 34 years ago, estimates have been heard that in the 21st century humanity will succeed in establishing colonies in space. The Moon is the most natural candidate for the location of such a colony, mainly because of its proximity to Earth. The average distance between the Earth and the Moon is about 384,400 kilometers - a relatively short distance that will make it easier to send supplies. Following a study published this week by American scientists, the likelihood of establishing colonies on the moon in the near term is increasing. The research shows that the frozen water reservoirs on the surface of the moon are five times larger than what was estimated until now. The new research will speed up the establishment of the colonies, due to the lowering of the costs of staying on the planet: according to the researchers, the future inhabitants of the moon will be able to thaw the water reservoirs and use them for drinking and producing oxygen.

In an article published in the journal Nature, researchers from the University of Hawaii claim that millions of years ago large amounts of water accumulated at both poles of the moon. Since the sun's rays do not warm the two poles, the reservoirs remain frozen. As a result, the amount of water has not decreased over the years. As early as 1998, NASA scientists documented ice deposits on the moon. Their amount was then estimated at several hundred million tons; The new estimate claims that it is about a billion tons.

The diameter of the moon is about 3,476 kilometers, and its mass is 81 times lighter than that of the earth. According to the accepted theory, the moon was formed together with the earth about 4.6 billion years ago. Its origin is not known with certainty: according to one of the approaches, it was created from material that was detached from the Earth or from remnants, which were created as a result of the collision of another planet with the Earth.

The team of researchers from Hawaii was able to estimate the size of the cratered area found in the shadowy parts of the moon. These areas remain perpetually clear, regardless of the changing of the seasons and the movement of the star. The researchers first calculated the average size of the craters in different places on the surface of the moon, and estimated that their average diameter at the poles is 20-1 kilometers. From this they concluded that the size of the shaded area at the North Pole is at least 7,500 square kilometers, and at least 6,500 square kilometers at the South Pole.

According to the American team members, the water on the moon was formed after the collision of comets and meteorites in its territory. The average temperature on the surface of the moon is minus 23 degrees Celsius, but the temperature at both poles is 10 times lower (about 230 degrees Celsius below zero). The intense cold froze the water reservoirs in the shaded area, preventing them from evaporating. Therefore, the larger the shaded areas, the more this affects the amount of water on the moon.

In recent years, the study of water in space has gained significant momentum. Just about a month and a half ago, American researchers claimed that snow that fell on the planet Mars millions of years ago caused the formation of the water reservoirs flowing on the planet.

NASA intends to review the findings presented in both studies soon. It intends to send an all-terrain vehicle to the Red Planet to investigate the water sources at the end of the year. At the same time, after years in which lunar exploration was neglected, NASA - as well as the European Space Agency and the new Chinese Space Agency - intend to return and send astronauts to it in the coming years.