A Lunar Exploration Neutron Detector (LEND) readied at the Space Research Institute of the Russian Academy of Sciences has been sent to the U.S. to be installed on the American Lunar Reconnaissance Orbiter (LRO), scheduled for launch in 2009. The aim of the mission is to map the Moon’s surface. The task of the Russian device is to look for hydrogen and hydrogen-bearing compounds, above all frozen water, in the lunar subsurface.
A companion event will be the “impacting” of the Moon to produce fresh information on the Earth’s natural satellite, and seek water resources, presumably of cometary origin. The launch vehicle and the instrument container will impact the Moon.
A similar technique was used in 2005 when scientists made a study of the Tempel-1 comet, into which a copper impactor weighing 369 kg was manoeuvred. Crashing into the comet at a speed of 170 metres a second, it gouged a crater the size of a football field and several dozen meters deep. The impact released energy equivalent to the explosion of 5 tonnes of TNT and caused the comet to eject a huge cloud of matter. This matter was analysed by instruments from the Deep Impact spacecraft.
Impacting is harmless for comets or the Moon. The Moon experienced the first effect of the kind in September 1959, when the Soviet Luna-2 probe crashed into it, or rather two separate machines crashed into it — the probe’s instrument package and the last stage of the launch vehicle. A dark round spot several kilometres across that erupted four seconds after the fall spread out to 40 km as observers watched. The results of the observation proved interesting but were never understood by astronomers.
Later, each abortive mission of lunar probes resulted in a hard landing on the Moon. But no special studies were made of their effects, or of the substances that were thrown up.
Lacking an atmosphere of its own, the Moon is constantly bombarded with solar wind and cometary or meteoritic particles. Near its southern pole there is an impact-formed crater, perhaps the largest of any in the Solar System.
The main aim of the NASA experiment is to validate a theory that the Moon may contain water, first voiced in 1998. Observations from artificial satellites have suggested that at least lenses of frozen water are imbedded in some craters around the poles, shadowed from the sun.
The Moon is the immediate possible next stage of human expansion in the universe and could be the first to host extra-terrestrial bases with an engineered environment. Future colonists will need both water and its components: oxygen and hydrogen, the former for breathing and the latter as rocket fuel, combined with oxygen. If water supplies are found on the Moon, there will be no need to deliver them from the Earth, and colonisation will be easier.
The search for water on the Moon is also important to understand the evolution of the Solar System. The most likely scenario is one in which water would collect in beds as comets fall on the moon. Each bed would chronicle a succession of cometary impacts over a billion or more years. This study would make it possible to trace the history of the system since its inception. One theory is of life having arrived on the Earth from space, brought by comets. A study of lunar cometary “leftovers” could yield fresh evidence favouring this view.
The impacting has been suggested by scientists from the Ames Research Centre in California. The idea of the project, code-named Blue Ice, is to use the reserve capacity of the Atlas-5 launch vehicle (its first stage is powered by the Russian RD-180 engine) to orbit a small additional research probe filled with optical, spectral and other equipment at the same time as the Lunar Orbiter. The probe is named the Lunar Crater Observation and Sensing Satellite, or LCROSS.
A distinctive feature of the Blue Ice craft is that the Russian-made LEND probe will do preliminary reconnaissance to determine the area of the most likely occurrence of water. It is into this region that the Centaur stage will smash. — RIA Novosti
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment