Gaia Space Observatory

Mapping the Milky Way in unprecedented detail.

Overview

Gaia is an ESA space observatory launched to create the most precise three-dimensional map of the Milky Way. By repeatedly scanning the sky, Gaia measures the positions, distances, and motions of over a billion stars.

Its data releases have revolutionised stellar astronomy, galactic structure studies, and even helped discover exoplanets and near-Earth objects.

📌 Mission Facts

Agency: ESA

Launch: 19 December 2013

Orbit: L2 Lagrange point

Goal: Billion-star survey of the Milky Way

Status: Operational (with multiple data releases)

Mission Objectives

  • Measure precise distances to over one billion stars.
  • Track proper motions and radial velocities.
  • Map the structure and formation history of the Milky Way.
  • Detect variable stars, binaries, and exoplanet candidates.

Why Gaia Matters

By turning the galaxy into a dynamic, moving system instead of a static star chart, Gaia allows astronomers to rewind and fast-forward the Milky Way’s evolution. It is a cornerstone for almost every branch of modern stellar and galactic astronomy.

Visualising the Galaxy

🔗 ESA — Gaia mission visualisation.
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