Cosma / Communication / Knowledge / Realm / Physical / Universe / Galaxy / Andromeda
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Introduction1
NASA Goddard (YouTube Channel)
NASA Goddard Space Flight Center (Official Website)
Encyclopedia
Andromeda Galaxy, also known as Messier 31, M31, or NGC 224, is a spiral galaxy approximately 780 kiloparsecs (2.5 million light-years) from Earth, and the nearest major galaxy to the Milky Way. Its name stems from the area of the sky in which it appears, the constellation of Andromeda.
The 2006 observations by the Spitzer Space Telescope revealed that the Andromeda Galaxy contains approximately one trillion stars, more than twice the number of the Milky Way’s estimated 200 to 400 billion stars. The Andromeda Galaxy, spanning approximately 220,000 light-years, is the largest galaxy in our Local Group, which is also home to the Triangulum Galaxy and other minor galaxies. The Andromeda Galaxy’s mass is estimated to be around 1.76 times that of the Milky Way Galaxy (~0.8-1.5×1012 solar masses vs the Milky Way’s 8.5×1011 solar masses). — Wikipedia
Andromeda (Encyclopædia Britannica)
Andromeda (COSMOS: The SAO Encyclopedia of Astronomy)
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Inspiration
This video begins with a ground-based view of the night sky, before zooming in on a Hubble image of the Andromeda galaxy — otherwise known as M31. The Hubble image of the galaxy is the biggest Hubble image ever released and shows over 100 million stars and thousands of star clusters embedded in a section of the galaxy’s pancake-shaped disc stretching across over 40 000 light-years.ESA/Hubble
Zooming in on the Andromeda Galaxy (ESA/Hubble)
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Innovation
Science
Extragalactic Astronomy is the branch of astronomy concerned with objects outside the Milky Way galaxy. In other words, it is the study of all astronomical objects which are not covered by galactic astronomy. The closest objects in extragalactic astronomy include the galaxies of the Local Group, which are close enough to allow very detailed analyses of their contents (e.g. supernova remnants, stellar associations). — Wikipedia
The Milky Way and Andromeda galaxies are expected to collide in ~4.5 billion years, merging to form a giant elliptical galaxy or a large disc galaxy. With an apparent magnitude of 3.4, the Andromeda Galaxy is among the brightest of the Messier objects — making it visible to the naked eye on moonless nights, even when viewed from areas with moderate light pollution. — Wikipedia
ScienceAtNASA (YouTube Channel)
NASA Science (Official Website)
This animation depicts the collision between our Milky Way galaxy and the Andromeda galaxy. Hubble Space Telescope observations indicate that the two galaxies, pulled together by their mutual gravity, will crash together about 4 billion years from now. Around 6 billion years from now, the two galaxies will merge to form a single galaxy. The video also shows the Triangulum galaxy, which will join in the collision and perhaps later merge with the Andromeda/Milky Way pair.
NASA Video (YouTube Channel)
NASA (Official Website)
Colliding Galaxies Videos (ViewSpace, Space Telescope Science Institute)
Interacting Galaxies: Future of the Milky Way Interactives (ViewSpace, Space Telescope Science Institute)
The Once and Future Stars of Andromeda (NASA Science)
Messier 31: The Andromeda Galaxy (Hubble’s Messier Catalog, NASA)
Andromeda Galaxy Videos (ViewSpace, Space Telescope Science Institute)
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Preservation
History
Dec. 30, 1924: Hubble Reveals We Are Not Alone (Randy Alfred, Wired Magazine)
Library
Subject: Andromeda Galaxy (Library Thing)
Subject: Andromeda Galaxy (Open Library)
Subject: Andromeda Galaxy (WorldCat)
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Participation
Education
MERLOT: Multimedia Educational Resource for Learning and Online Teaching
OER Commons: Open Educational Resources
Community
News
Andreomeda Galaxy (JSTOR)
Andreomeda (EurekaAlert, AAAS)” target=”_blank” rel=”noopener”>Andromeda Galaxy (EurekaAlert, AAAS)
Andromeda Galaxy (Astronomy Magazine)
Andromeda (Phys.org)
Recent News from Phys.org …
- Hubble reveals spiral galaxy 53 million...
on April 30, 2026 at 4:20 pmIn this new image by the NASA/ESA Hubble Space Telescope, a spiral galaxy glittering with star clusters is the center of attention. NGC 3137 is located 53 million light-years away in the constellation Antlia (The Air Pump). As a nearby spiral galaxy, this target offers astronomers an excellent opportunity to study the cycle of stellar birth and death, as well as giving researchers a glimpse of a galactic system similar to our own.
- ALMA reveals giant molecular clouds across Needle...
on April 28, 2026 at 12:20 pmAn international team of astronomers has employed the Atacama Large Millimeter/submillimeter Array (ALMA) to perform high-resolution observations of the Needle galaxy. Results of the new observational campaign, presented April 15 on the arXiv preprint server, provide more insights into the properties of molecular gas in this galaxy.
- Astronomers discover Andromeda XXXVI, an...
on April 7, 2026 at 12:10 pmBy analyzing the data from the Pan-Andromeda Archaeological Survey (PandAS), European astronomers have discovered a new satellite of the Andromeda galaxy. The newfound object, which received the designation Andromeda XXXVI, appears to be an ultra-faint dwarf galaxy. The finding is reported in a paper published March 30 on the arXiv preprint server .
- New Henrietta spectrograph to probe alien...
on March 30, 2026 at 4:00 pmFinding life beyond our solar system goes beyond measuring an exoplanet's size, as rocky, Earth-sized worlds might not have the conditions for life as we know it. While exoplanets can be directly imaged by blocking their star's glare, these images are fuzzy and lack resolution to provide enough details about the habitability. Therefore, astronomers are limited to studying an exoplanet's atmosphere, and this has proven to be quite beneficial in teaching scientists about an exoplanet's formation […]
- Strange cosmic burst from colliding galaxies...
on March 10, 2026 at 2:00 pmA recently detected flash of energy appears to have emanated from the wreckage of colliding galaxies, according to an international team of astronomers led by Penn State scientists. The burst, known as GRB 230906A, was likely caused by the collision of two neutron stars hundreds of millions of years ago and is now shedding light on how the universe creates some of its heaviest elements.
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Related
Here are links to pages about closely related subjects.
“Fundamentals”
Law (Constant) Relativity
Force Gravity, Electromagnetism (Light, Color)
Matter (Microscope) Molecule, Atom (Periodic Table), Particle
“Space”
Universe (Astronomical Instrument)
Galaxy Milky Way, Andromeda
Planetary System Star, Brown Dwarf, Planet, Moon
Our Neighborhood
Solar System Sun
Terrestrial Planet Mercury, Venus, Earth (Moon), Mars
Asteroid Belt Ceres, Vesta
Jovian Planet Jupiter, Saturn, Uranus, Neptune
Trans-Neptunian Object
Kuiper Belt Pluto, Haumea, Makemake
Scattered Disc Eris, Sedna, Planet X
Oort Cloud Etc. Scholz’s Star
Small Body Comet, Centaur, Asteroid
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Notes
1. The resources on this page are are organized by a classification scheme developed exclusively for Cosma.