Galaxy clusters are the largest known gravitationally bound structures in the universe, containing hundreds to thousands of galaxies, hot plasma, and a large amount of invisible dark matter. They are key probes of the large-scale structure and evolution of the cosmos.
Laniakea is the galaxy supercluster that is home to the Milky Way and approximately 100,000 other nearby galaxies. It spans 520 million light-years and illustrates the large-scale structure of the universe.
Laniakea is the galaxy supercluster that is home to the Milky Way and approximately 100,000 other nearby galaxies. It spans 520 million light-years and illustrates the large-scale structure of the universe.
Gravitational Wave
GW170817 detected from NGC 4993
GW170817 was a gravitational wave signal observed by the LIGO and Virgo detectors on 17 August 2017. The signal originated from the elliptical galaxy NGC 4993, representing the first ever observation of a binary neutron star merger.
Date: 17 Aug 2017
Source: NGC 4993
Type: Neutron Star Merger
Galaxy Cluster
Largest Known Structures
Galaxy clusters are the largest known gravitationally bound structures in the universe, containing hundreds to thousands of galaxies, hot plasma, and a large amount of invisible dark matter. They are key probes of the large-scale structure and evolution of the cosmos.
Members: 100-1000+ galaxies
Diameter: 10-30 million ly
Mass: 10^14-10^15 M☉
Dark Matter
The Invisible Scaffold
Dark matter is a hypothetical form of matter that appears to account for approximately 85% of the matter in the universe. It does not interact with electromagnetic radiation, making it invisible, but its existence is inferred from its gravitational effects on visible matter.
Universe %: 27% of total
Detection: Gravity only
Type: Non-baryonic (unknown)
Dark Energy
The Universe's Accelerant
Dark energy is an unknown form of energy that affects the universe on the largest scales. It is the primary evidence for the observation that the expansion of the universe is accelerating. It is estimated to make up roughly 68% of the total energy in the observable universe.