Megascale engineering is concerned with the construction of structures on a huge scale, typically 1000 kilometers or more. However, nanotechnology is concerned with the almost atomic level of construction and design. Megascale engineering deals with huge structures, sometimes spanning the whole celestial bodies. It is also concerned with the colonization of planets and the transformation of celestial bodies into habitable places for the mankind. A Megastructure, as the name suggests, is a large man-made object that is visible even from the outer space. An example of a Megastructure is the Great Wall of China.
On the other hand, Astroengineering is a branch of Megascale engineering that deals with engineering on an astronomical scale. It is, however, fictional and best describes the construction of mega structures by the more advanced beings different from humans. These mega structures are “observable” from the earth and some examples include the planet-sized artificial worlds, like the Halo Array, Onyx, Shield 0459, Dyson Spheres, and installation 00.
Nanotechnology was discovered almost 30 years ago and it is projected to take over many industries as we advance technologically. The medical application of nanotechnology is known as nanomedicine. It is highly effective in drug delivery to some specific organs in the human body. With nanotechnology, cancer has already been cured in mice and is awaiting human testing.
Nano Biotechnology is another application of nanotechnology. It is the intersection of biology and nanotechnology. Nano biotechnology has helped scientists create and implement systems useful for research purposes in the field. Other applications of nanotechnology are involved in the energy sector (increased efficiency in production and significant reduction of consumption), Aerospace industry (reduction in weight of materials), vehicle manufacturing, foods, computing (memory and storage, integrated circuit chips, CPUS, quantum computers), environmental sanitization and filtration, tissue engineering and tissue culture in agriculture, construction sector and many more fields.