WHAT IS A COSMIC VOID?
A cosmic void is a huge region of the
Universe where galaxies and matter are
much less concentrated than average.
They are not completely empty. Extremely
thin gas, dark matter and occasional
galaxies can still exist inside them.
Voids are surrounded by denser structures
such as galaxy filaments, sheets and
clusters.
THE COSMIC WEB
On the largest scales, matter in the
Universe forms a vast network known as
the cosmic web.
Galaxies gather along enormous filaments
and walls, while huge empty regions form
between them.
Gravity gradually pulled matter toward
denser regions, leaving some areas with
far fewer galaxies.
ARE VOIDS REALLY EMPTY?
No.
A cosmic void is not a perfect vacuum.
It can contain extremely diffuse gas,
dark matter and isolated galaxies.
The important difference is density:
there is dramatically less matter than
in the surrounding cosmic structures.
HOW DID VOIDS FORM?
Tiny variations in the density of the
early Universe grew under gravity.
Matter flowed away from underdense regions
and toward denser ones.
Over billions of years, these differences
became the enormous network of clusters,
filaments and voids that we observe today.
THE STRUCTURE OF THE UNIVERSE
GIANT SCALE
Some cosmic voids stretch across
hundreds of millions of light-years.
FEW GALAXIES
Galaxies are much less common inside
voids than in galaxy clusters and filaments.
DARK MATTER
Voids also contain less dark matter
than the surrounding cosmic web.
GALAXY WALLS
Dense sheets and filaments often form
the boundaries around cosmic voids.
ANCIENT STRUCTURE
Voids developed over billions of years
as cosmic matter evolved under gravity.
COSMIC MAP
Mapping voids helps astronomers understand
the large-scale evolution of the Universe.
DID YOU KNOW?
The Universe is not simply a collection
of galaxies scattered randomly through space.
On enormous scales, galaxies form a
cosmic web — and the vast emptiness between
its threads can be just as important as
the galaxies themselves.
VOIDS IN THE COSMIC WEB
Cosmic voids are enormous regions containing much less matter than the cosmic average, but they are not literally empty. Galaxies and diffuse matter can still exist inside them. Voids are surrounded by denser filaments, walls and clusters that together form the large-scale cosmic web.
Their sizes, shapes and galaxy populations provide information about how structure grew under gravity as the Universe evolved. Researchers also use statistical studies of voids alongside other cosmological observations to test models of matter and cosmic expansion.
Galaxies · Dark Matter · Dark Energy