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Milky Way Galaxy

Our home galaxy. The Milky Way is a spiral galaxy with four major arms containing young bright stars, gas, and dust. The mass of the Milky Way is estimated to be between 400 billion and one trillion times the mass of the Sun. The Milky Way’s diameter is about 100,000 light-years, with the Sun orbiting about 27,000 light-years from the galactic center. However, most of the galaxy’s mass consists of “dark matter” which encircles the Milky Way’s disk in a vast halo. Dark matter may account for 90 percent of the Milky Way’s mass.

Resources

Facts and Figures June 10, 2010
The Sun and our solar system lie in the "thin disk" of our galaxy.

The Milky Way May 21, 2010

Radio Programs

Close Clusters Two star clusters that stick together May 12, 2018

Camelopardalis Darkness above the Milky Way April 8, 2018

Streamers New arrivals in the Milky Way April 3, 2018

Galactic Empire The hub of a galactic empire March 27, 2018

Milky Way Clusters Families of stars in the Milky Way March 11, 2018

Winter Milky Way Gazing beyond the starry Milky Way February 12, 2018

Milky Way Center Discovering the galaxy’s distant heart August 26, 2017

Black-Hole Blobs A black hole fires some rockets August 12, 2017

Far, Far Away Mapping the distance to the galactic center July 22, 2017

Heading North Heading north through the Milky Way May 26, 2017

Event Horizon Telescope Looking for a giant black hole April 4, 2017

Local Group IV A collision course for the Milky Way January 12, 2017

Local Group III A faint satellite of the Milky Way January 11, 2017

November Milky Way Looking toward the galactic rim November 19, 2016

Doomed Pleiades A beautiful but doomed cluster November 17, 2016

Old Clusters Scanning for the distant past September 30, 2016

Milky Way Halo Extending our home galaxy September 29, 2016

The Milky Way Mapping out the Milky Way galaxy September 28, 2016

Shredded Cluster Shredding an ancient star cluster August 17, 2016

Dark Downtown? The glow of the galaxy’s busy downtown August 16, 2016

Smith’s Cloud A big cloud falls toward the Milky Way August 14, 2016

Milky Way Hiding behind a cosmic haze July 29, 2016

Scutum Arm Wrapping an arm around the galaxy July 25, 2016

Hydra I A faint companion to the Milky Way April 1, 2016

Winter Milky Way Adding to the winter Milky Way January 27, 2016

Sculptor Looking into a galactic well December 10, 2015

Faintest Cluster A faint cluster that’s doomed October 3, 2015

Far, Far Away Mapping the distance to the galactic center August 13, 2015

Galactic Hub Visiting downtown Milky Way August 12, 2015

Sagittarius Steaming up the center of the galaxy August 11, 2015

Fermi Bubbles Blowing bubbles in the Milky Way July 19, 2015

Stellar Metals A difference between young and old stars July 14, 2015

Omega Centauri Alien visitors from other galaxies May 25, 2015

M92 An ancient family of stars May 12, 2015

North Poles Looking north from the Milky Way May 8, 2015

Orion Arm A short “arm” of the Milky Way February 17, 2015

Winter Milky Way Looking toward the galaxy’s outskirts February 16, 2015

Survivor The heart of the galaxy stays quiet January 11, 2015

Featured Images

A swirl of stars at the center of the Milky Way contains a supermassive black hole

Looking for Darkness April 4, 2017
sequence of images depicting the merger of M31 and Milky Way galaxies

Crash Course January 11, 2017
Labeled structure of the Milky Way galaxy

Arming the Milky Way September 28, 2016
Map of the Milky Way's spiral arms

Starry Arms July 25, 2016
Multi-wavelength view of the center of the Milky Way galaxy

Galactic Hub August 13, 2015
Artist's concept of Fermi bubbles

Blowing Bubbles July 20, 2015
Hubble Space Telescope view of the core of M13, a globular cluster in Hercules

Old Sparklers May 12, 2015
G2 survives its swing around the black hole at the center of the Milky Way

Narrow Escape March 27, 2015
The Milky Way galaxy's spiral arms

Arming the Milky Way February 18, 2015
Artist's concept of hot gas funneling toward black hole at center of Milky Way

Dark Center July 29, 2014
A view of the busy Milky Way

Busy Galaxy July 24, 2014
The Milky Way glows above the Nevada desert

Dig Site March 24, 2014
Artist's concept of the Milky Way galaxy and its dark matter halo

Illuminating the Darkness February 9, 2013
Multispectral view of giant star-forming regions at the center of the Milky Way

Molecule Factory November 13, 2012
Andromeda and the Milky Way head for a galactic pile-up

Collision Course September 12, 2012
Artist's concept of stars and a gas cloud near the Milky Way's central black hol

Snack Time March 29, 2012
Two globular clusters; a previously known one at right, and a new one in circle

Star City October 19, 2011
Stars and gas swirl around the black hole at the center of the Milky Way

Swirling Center September 27, 2011
Artist's concept of a free-floating planet in the Milky Way galaxy

Free Agent May 19, 2011

Cold Fingers March 19, 2010