Sky Surveys: Cataloging Billions of Stars and Galaxies

Sky surveys systematically scan the heavens to map stars, galaxies, and cosmic structures.
The first photographic surveys in the late 1800s created detailed star charts.
Modern digital surveys capture terabytes of data every night.
The Sloan Digital Sky Survey (SDSS) has cataloged millions of galaxies and quasars.
Gaia, launched by ESA, is mapping over a billion stars in 3D with incredible precision.
Surveys help discover exoplanets by tracking tiny dips in starlight.
They also uncover supernovae, asteroids, and other transient events.
Infrared and radio surveys reveal hidden structures invisible to optical telescopes.
Sky surveys are crucial for studying dark matter, dark energy, and the large-scale universe.
Together, they create the most comprehensive cosmic maps in human history.