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Historical record · A changing planet

Earth

Follow the planet from its formation through changing rocks, atmosphere, life and climate.

Primary topic: Nature & the Universe

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Scope of this guide

A selective planetary history, with rounded geological ages and existing life chapters reused. Formation models and ancient climates retain uncertainty. The modern endpoint is NASA’s temperature record through 2025, reported in February 2026.

Actual source-review status

5 completed · 1 partial · 4 pending chapter reviews in this subject.

The factual audit is unfinished. These counts come from recorded chapter reviews, not legacy “reviewed” wording, confidence labels or image checks. A completed source review retains scientific and historical uncertainty.

Key chapters

  1. c. 4.54 billion years ago

    Earth takes shape →

    Rock and metal gather around the young Sun.

    Full chapter source review pending. Confidence labels are editorial assessments.
  2. c. 720–635 million years ago

    Ice reaches ancient tropical regions →

    Geological evidence points to severe glaciation.

    Chapter source review completed: 2026-10-11 · Codex expansion source review. Scientific uncertainty is retained in the evidence note.
  3. 2025

    A measured record of a warmer planet →

    2023, 2024 and 2025 form NASA’s three warmest recorded years.

    Chapter source review completed: 2026-10-11 · Codex expansion source review. Scientific uncertainty is retained in the evidence note.

Connected roads

These are authored connections in the existing catalogue, not an automatically inferred family tree.

All chapters & review records

Sources

Sources cited by the existing chapters. Listing a source does not mean every claim has been verified.