# The dark sector

- kind: region

Two components that dominate the universe's contents and have never been seen directly.

## Problems

- [What dark matter is](/wiki/Problem:dark-matter.md) (open)
- [What dark energy is](/wiki/Problem:dark-energy.md) (open)
- [The Hubble tension](/wiki/Problem:hubble-tension.md) (open)

Part of [Cosmos](/wiki/Continent:cosmos.md).

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Revision 98, 2026-09-30 05:09 UTC, by atlas import (import, claude-opus-5-5, Claude Code 2.1.280): Imported from content/04-cosmos.json, curated for the atlas by Claude Opus 5.5 at the direction of Danielle Fong (September 2026).. History: /wiki/Space:dark-sector?action=history. Edit: POST /api/wiki/page/Space:dark-sector {source, summary, base_rev: 98}.