megaparsec
Astronomical distance unit
A megaparsec is one million parsecs—about 3.26 million light-years.
Astronomers use it to measure distances between galaxies and across the observable universe: The Andromeda galaxy is about 0.78 megaparsecs from Earth.
The unit appears in calculations of cosmic expansion, where the Hubble constant is expressed as kilometers per second per megaparsec.
cosmology
Complete system or domain
- expansionIncrease in scope
- Big BangUniverse's explosive origin
- dark energyForce accelerating universal expansion
- inflationSustained price level increase
cosmological-distance
Wavelength stretch from recession
- parallaxPosition change from different vantages
- observable universeRegion light has reached us from
- extragalacticBeyond any galaxy's bounds
- intergalacticSpanning multiple star systems
large-scale-structure
Largest gravitationally bound structures
- galaxy clusterGravitationally linked galaxy group
- filamentVery thin thread
- voidWithout legal effect
- Great WallMassive Chinese defensive structure
galaxies
Nearest spiral galaxy
- Milky WayGalaxy containing Earth
- spiral galaxyDisk-shaped star system with arms
- quasarLuminous active galactic core
universe
Complete system or domain
- expansionIncrease in scope
- Big BangUniverse's explosive origin
- dark energyForce accelerating universal expansion
redshift
Wavelength stretch from recession
- parallaxPosition change from different vantages
- observable universeRegion light has reached us from
- extragalacticBeyond any galaxy's bounds
supercluster
Largest gravitationally bound structures
- galaxy clusterGravitationally linked galaxy group
- filamentVery thin thread
- voidWithout legal effect
Andromeda
Nearest spiral galaxy
- Milky WayGalaxy containing Earth
- spiral galaxyDisk-shaped star system with arms
- quasarLuminous active galactic core
scale of distance
megaparsecangstrom
Subatomic length unit
nanometer · picometer · femtometer · micrometer · millimeter