LONG BEFORE

About

A very long story of Earth

LONG BEFORE helps children feel how much time Earth has had. It is not a dinosaur catalogue, a geology textbook, or a quiz.

Sit together if you can. A grown-up does not have to teach. Rewind is the toy. The picture changes. Wonder, then look. First look is enough. Keep looking is how we know, if you want more. This is not homework, and it is not a test.

The primary verb is rewind. Human history is the doorway where this story almost ends and a sister story about civilizations, Before Us, would begin.

Wonder Atlas looks out into the sky. This project looks backward through Earth. How Do We Know? teaches evidence more broadly. Could We Live There? asks about other worlds. LONG BEFORE’s office is deep time.

Method

  • Dates in deep time often have uncertainty. A number like ~66 million is a current estimate, not a birthday.
  • Some boundaries are defined by a golden spike in rock. Many biological changes happened over long intervals.
  • Reconstructions are models. Color, sound, and soft tissue are usually inferred.
  • A map of the past is a model, not a surveyed coast.
  • First life remains a question. We publish the oldest evidence we can defend, and we mark the rest as contested.

Sources

  • International Chronostratigraphic Chart v2026/06

    International Commission on Stratigraphy

    Eon, era, period, and epoch boundaries; Holocene 0.0117 Ma; K-Pg 66.00 Ma; Cambrian 538.8 ± 0.6 Ma

    Open source

  • The ICS international chronostratigraphic chart this decade

    Cohen, Harper, Gibbard and Car, Episodes 2025

    How the chart encodes numerical ages and uncertainty

    Open source

  • Age of the Earth

    U.S. Geological Survey

    Earth ~4.54 billion years; solar-system CAIs ~4.567 billion years

    Open source

  • Key facts about human origins

    Smithsonian Institution

    Homo sapiens ~300,000 years; branching hominin story

    Open source

  • Early life on Earth. Animal origins

    Smithsonian National Museum of Natural History

    Microbial signals ~3.7 Ga; stromatolites ~3.5 Ga

    Open source

  • What the earliest evidence for life tells us about the early Earth

    Royal Society / Westall 2025

    Dresser Formation stromatolites 3.48 Ga; contested older claims

    Open source

  • Oxygenation, life, and the planetary system

    Lyons et al. 2021

    Great Oxidation Event about 2.4 to 2.3 Ga; later Neoproterozoic rise

    Open source

  • How the Moon formed

    NASA

    Giant-impact context for a young Earth and Moon system

    Open source

  • The Earth seen from Apollo 17

    NASA

    Real photograph of Earth now, beside a drawing of Earth forming

    Open source

  • Grand Canyon from Hopi Point

    U.S. National Park Service

    Real photograph of the canyon now. Public domain U.S. government work

    Open source

  • Exit Glacier

    U.S. National Park Service

    Real photograph of a living glacier beside a drawing of Pleistocene ice

    Open source

Generated pictures of the past are interpretations, not photographs. No accounts. No ads. No precise location. Dates follow the ICS chart v2026/06 and USGS Earth-age guidance.