In science fiction, a megastructure is an artificial construct of enormous size, the product of megascale engineering. They are typically measured in at least hundreds of miles in at least one dimension and are commonly space habitats of some sort. Megastructures often play a major part in the plot of science fiction movies and books.

Existing megastructures

• The Great Barrier Reef, at 2 Mm in length, is an artificial megastructure (albeit one not assembled by humans).
• The Great Wall of China is a human-built megastructure, 6.7 Mm in length.

Space-based science fiction megastructures

Megastructures that are larger than planets include:

• Alderson disk
• Culture Orbital
• Dyson sphere
• Ringworld

Sub-planetary structures include:

• Death Star
• Lofstrom loop

Orbital Structures include:

• Space elevator/Orbital tower
• Skyhook/Rotovator
• Orbital ring

Other science fiction megastructures

• In the manga Blame! the Megastructure is a vast and chaotic complex of metal, concrete, stone, etc, that covers the whole Earth and assimilates even the Moon. The Megastructure continues to expand by itself, being built by robots called builders . The whole history of the manga takes place deep inside of the structure, where there is no sea or sky, and the characters find themselves climbing up thousand of kilometers of labyrinths searching for Net Terminal Genes.
• Mega-City One and several other cities in the Judge Dredd comic book series are megascale constructs.
• In the game Necromunda from Games Workshop huge, stalagmite-like cities form the setting of various conflicts based in the larger Warhammer 40,000 universe.

External links

• Megastructures