distance ladder
Astronomical measurement chain
A distance ladder (or cosmic distance ladder) is the sequence of methods astronomers use to measure increasingly remote objects in space.
No single technique works at all scales, so each method calibrates the next: parallax measurements establish nearby star distances, which calibrate certain variable stars, which in turn calibrate supernova brightness for measuring distant galaxies.
The distance ladder lets us estimate how far away objects are across the observable universe.
- parsecInterstellar length measure
- redshiftWavelength stretch from recession
- variable starCelestial body with fluctuating brightness
- parallaxPosition change from different vantages
- supernovaExploding massive star
cosmology · rung · magnitude · Hubble · luminosity · measurement · measuring tape · astronomy · galaxies · deep space · expansion · universe · stellar · calibration · brightness · scale · faraway · cosmic
- astronomystars, moon, sun, planet, planets
- cosmic distanceslight-years, parsecs, megaparsec, light years, astronomical units