In science, a phenomenon known granular convection, also known as the Brazil nut effect. The essence of it is that by shaking the container with the largest heterogeneous nuts are always at the top. Vibration leads to the formation of voids, which fail smaller nuts ... The same thing is happening on the surface of planets and asteroids.
Of course, it#39;s not just about nuts. For example, in the same way, a layer of sand on the banks of earth ponds: turn on the largest grains and at the bottom - the ones smaller ... In this process, the intensity can be varied depending on the gravity. Recently Güttler Karsten and his colleagues from Technical University of Braunschweig (Germany) decided to see how it will look the Brazil nut effect beyond Earth.
The same granular array first tested in the laboratory and then on board a wide-bodied cargo aircraft A-300, which excrete a variety of parabolic maneuvers in the form of a parabola, simulating gravity that is present on the surface of the Moon and Mars, as you know, lower than Earth. During the experiments, the researchers placed on the container bottom green glass beads with a diameter of 8 millimeters, and the remaining volume filled with balls with a diameter of 1 millimeter. A special device for shaking ensured mixing balls.
After comparing the results obtained in different conditions. It was found that, in laboratory experiments, that is, the earth#39;s gravity, the effect of granular convection appear to be strong. In this case, we could speak of a linear relationship. That is, in terms of the Moon and Mars, nuts or any large sized rocks composed of large particles in areas of seismic activity would have been at the top is not as fast as on Earth.
Early last year, co-owner of the company Space Adventures and a member of the supervisory board of the Civil NASA Richard Garriott on the SXSW conference in Austin (TX) has proposed to seek minerals ... on asteroids. The current level of technology allows the identification of valuable substances and ore, after which it will be possible to organize an expedition for the purpose of delivering them to Earth, he said. Establish production from the bowels of the asteroid platinum, iridium and rhodium proposed company Planetary Resources. In the coming years, Planetary Resources plans to launch two to five space-based telescope Arkyd-101, which will help to find the most suitable for this purpose asteroid. A major phase of the project is scheduled for the 30 years.
In turn, the company Deep Space Industries proposed to use to search for minerals on asteroids orbiting robotic explorers that will determine the value of the cosmic body in terms of availability of rare earth materials. The first such device is planned to start in two years. Speaking of the average outer body weight of 500 tons, it will contain approximately 200 tons of silicates, 100 tons of water, 100 tons of carbon compounds, and finally, 90 tons of metals such as iron, nickel and cobalt. This container with minerals could be used for the construction of the space base in the Lagrange point L2, which is located in the 61,000 kilometers of the moon.
The most promising yet recognized project proposed Deep Space. The first model will be called the geological robot FireFu Firefly. Robots weighing about 25 pounds to go into space in 2015. Their term of between 2 to 6 months. However, according to the researchers, the weaker the gravity, the less has to say about the principle of linearity. Thus, the gravity on asteroids is hundreds of times smaller than the Earth, and the cohesive forces between the particles of the individual species play a greater role than gravity.
Therefore, if humanity will ever develop the asteroids, the effects of shock deformation may differ significantly from those to which they are accustomed earth experts on mining. Therefore the safety of asteroid and comet drilling may be different than on Earth. All this means that the geological processes associated with granular convection with a low level of gravity can be much slower than in the world. Consequently, scientists can make mistakes in dating geological formations of the Moon and Mars, not to mention the smaller space bodies.
