Distance indicator · Geometric rung
Water Megamaser Distances
A direct, geometric distance measured from water masers orbiting in the accretion disc around a galaxy's central black hole. By tracking their motion and acceleration, the physical size of the disc is found and compared with its angular size — a one-step distance that anchors the ladder without relying on standard candles.
Highlights
- ›A one-step geometric distance, independent of standard candles
Methods, objects & facilities
Knowledge connections
- Associated withThe Cosmic Distance Ladder
- Associated withThe Hubble Constant
Sources
The primary and reference sources this topic draws on.
- NASANational Aeronautics and Space Administration
Mission data, planetary science, space telescopes, and public-domain imagery.
Most NASA-produced imagery is in the public domain; individual items are checked for usage terms before publication.