Galaxies · Spiral galaxy
Andromeda Galaxy
2.5 million light-years · Light crosses it in 152,000 years
- Across
- 152,000 light-years
- Vs Earth
- 1.52× Milky Way
- Mass
- 1.5 trillion Suns
Open Andromeda Galaxy in Cosmic Scale
In the app, Andromeda Galaxy is part of the Beyond pack.
About
Andromeda is the nearest large galaxy and the most distant thing most people can see without a telescope. Its light left 2.5 million years ago, when our ancestors were first making stone tools.
Heading toward the Milky Way at 110 km/s — the two will merge in about 4.5 billion years.
At a glance
| Distance | 2.5 million light-years |
|---|---|
| Stars | About 1 trillion |
| Diameter | 152,000 light-years |
| Also known as | M31 |
Did you know
- It is approaching us at 110 km/s; the two galaxies will merge into one huge elliptical.
- The Persian astronomer al-Sufi described it as a 'small cloud' in AD 964.
- In 1923 Edwin Hubble showed it lies far outside the Milky Way, proving that other galaxies exist.
Simulations
- The Milky Way meets Andromeda — How our galaxy and its giant neighbour may merge into one, over billions of years
Real photos
- Hubble's largest photomosaic: 200 million stars across the Andromeda Galaxy, 2025 — NASA, ESA, B. Williams (University of Washington) (CC BY 4.0) · source
- Part of Andromeda's disk resolved into over 100 million stars, Hubble — NASA, ESA, J. Dalcanton (University of Washington, USA), B. F. Williams (University of Washington, USA), L. C. Johnson (University of Washington, USA), the PHAT team, and R. Gendler (CC BY 4.0) · source