- The Atacama Large Millimeter/submillimeter Array (ALMA) is the world’s most powerful observatory for studying the universe at the long-wavelength millimeter and submillimeter range of light.
- It’s designed to spot some of the most distant, ancient galaxies ever seen, and to probe the areas around young stars for planets in the process of forming.
- The opening of the telescope array is being celebrated in an inauguration ceremony on Wednesday (March 13) at its observation site in Chile’s Atacama desert. Here are six things you should know about the ambitious, not to mention immense, astronomy project.
- The observatory is among the highest instruments on Earth, at an altitude of 16,570 feet (5,050 meters) above sea level. Its perch high atop the Chajnantor plateau puts it above much of the Earth’s atmosphere, which blurs and distorts light.
- ALMA’s location in Chile’s Atacama desert, the driest place in the world, means almost every night is clear of clouds and free of light-distorting moisture. Some weather stations in the desert have never received rain, and scientists think the Atacama got no significant rainfall between 1570 and 1971.
- The surfaces of its dozens of radio dishes are almost perfect, with none deviating from an exact parabola by more than 20 micrometers (20 millionths of a meter, or about 0.00078 inches).
- This prevents any incoming radio waves from being lost, so that the resulting picture captures as much distant cosmic light as possible.
- The radio dishes, which weigh about 100 tons each, are made of ultra-stable CFRP (Carbon Fiber Reinforced Plastic) for the reflector base, with reflecting panels of rhodium-coated nickel.
Carbon fiber reinforced polymer:
- An extremely strong and light fiber-reinforced plastic which contains carbon fibers.
- The spelling ‘fibre’ is common in British Commonwealth countries.
- CFRPs can be expensive to produce but are commonly used wherever high strength-to-weight ratio and rigidity are required, such as aerospace, automotive, civil engineering, sports goods and an increasing number of other consumer and technical applications.
- The binding polymer is often a thermoset resin such as epoxy, but other thermoset or thermoplastic polymers, such as polyester, vinyl ester or nylon, are sometimes used.
- The composite may contain other fibers, such as an aramid (e.g. Kevlar, Twaron), aluminium, ultra-high-molecular-weight polyethylene (UHMWPE) or glass fibers, as well as carbon fiber.
- The properties of the final CFRP product can also be affected by the type of additives introduced to the binding matrix (the resin).
- The most frequent additive is silica, but other additives such as rubber and carbon nanotubes can be used.
- The material is also referred to as graphite-reinforced polymer or graphite fiber-reinforced polymer (GFRP is less common, as it clashes with glass-(fiber)-reinforced polymer). In product advertisements, it is sometimes referred to simply as graphite fiber for short.