Experts say that future expeditions to the Moon may face quite a few dangers. One of them is meteorite attacks. The Moon has practically no atmosphere that would have braked the flights of meteorites, and the possibility that a meteorite may seriously injure an astronaut or damage a spaceship or another faciliy is rather high on the Moon. However, experts also suggest some measures to minimize these risks.

Within the last 8 years, scientists have been holding a constant monitoring of the Moon's surface. Every hit of a meteorite against the Moon's surface (as a rule, these hits are accompanied with light flashes) is fixed by telescopes on the Earth. Within this period, more than 300 such flashes have been registered.

The most powerful one took place in September 2013. Recently, its details were published. The meteorite's weight was 400 kgs, and it flew at the speed of 17 kms per second. The energy from its blow, as scientists say, was equal to an explosion of 15 tons of tritol.

The meteorite's fall produced a crater with the diameter of 40 meters on the Moon's surface. For observers from the Earth, the flash from this blow was as bright as, say, the Polar Star. One can only imagine what would have remained from a house if it experienced such a blow.

However, the possibility that such a huge asteroid may hit an astronaut or a space facility on the Moon is nearly equal to nil - this may happen only once in several thousand years.

"However, there are much more chances that astronauts on the Moon may be hit by a much smaller particle," Oleg Malkov from the Russian Institute of Astronomy says.

"A microscopic grain flying at a very high speed is able to perforate an astronaut's spacesuit, and the astronaut may suffocate. The Moon is being bombarded by small particles from space practically every moment. We cannot see this from the Earth because these particles are too small. But astronauts on the Moon would feel it sooner or later."

Some 40 years ago, the US, within the framework of the Apollo program, sent several expeditions to the Moon with people's landings on the Moon's service. At that time, the danger of small meteorites' attacks was underestimated. Fortunately, no one of the astronauts has suffered, but this was a mere accidence.

"Future missions to the Moon would necessarily undertake protective measures," another Russian astronomer, Vladimir Surdin from the Moscow State University, says.

"If a long-term dwelling site is built on the Moon, it would be better to build it under the ground, at the depth of at least 2 or 3 meters," Vladimir Surdin says.

"This would protect this facility from meteorites' attacks. Judging from the frequency of meteorite blows on the Moon, the facility would experience such blows once in several years. It would be quite easy to dig the Moon's ground because it is rather soft and the gravity on the Moon is week. Space agencies that are planning expeditions to the Moon are already taking this into account. Quite likely, underground facilities for astronauts will start to be built on the Moon already in the foreseeable future."

Being under the ground would also protect people from radiation, which is rather strong on the Moon, as well. But what should be done if a person still needs to come up to the Moon's surface? To put on a spacesuit with a thick cover of armor?

Well, even if this is physically possible, this would hardly be useful because even a small meteorite flying at a high speed can perforate any armor. It looks like the only way to protect oneself from meteorite attack on the Moon is to take to the surface as rarely as possible and to use robots, instead of people, for working on the surface.

"It would probably be useful to send expeditions to the Moon to the places where large meteorites have recently fallen," Vladimir Surdin continues.

"This would be very useful for examining the Moon's subsurface resources. So far, no one has drilled pits deeper than about 2 meters on the Moon. Meanwhile, a fall of a large meteorite can make a several-dozen-deep pit on the Moon's surface, and the only thing left to geologists is to take samples of soil from the Moon's depths right from this pit - fresh and earlier unexamined samples."

Scientists are gradually collecting more and more information about meteorite attacks on the Moon. For nearly 5 years, NASA's satellite has been rotating around the Moon. From March 2013 till this March, this satellite has "noticed" more than 20 earlier unknown craters and more than 200 traces from meteorites' fragments on the Moon's surface.

It was especially important to discover that fragments of the Moon's ground that scatter as a result of a meteorite's blow may fly within the radius of several dozen kilometers, creating a wide dangerous zone. The planners of future expeditions to the Moon will now take this into account.

Source: Voice of Russia