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.


Facts and Figures The biggest, farthest and fastest in the...
The Milky Way The Milky Way consists of a bulge of stars in...

Radio Programs

Winter Milky Way Adding to the winter Milky Way Wednesday, January 27, 2016
Sculptor Looking into a galactic well Thursday, December 10, 2015
John Stanley Plaskett Taking the measure of the Milky Way Tuesday, November 17, 2015
Busy Galaxy The busy, beautiful Milky Way Saturday, November 7, 2015
Faintest Cluster A faint cluster that’s doomed Sunday, October 4, 2015
Far, Far Away Mapping the distance to the galactic center Friday, August 14, 2015
Galactic Hub Visiting downtown Milky Way Thursday, August 13, 2015
Sagittarius Steaming up the center of the galaxy Wednesday, August 12, 2015
Fermi Bubbles Blowing bubbles in the Milky Way Monday, July 20, 2015
Stellar Metals A difference between young and old stars Wednesday, July 15, 2015
Omega Centauri Alien visitors from other galaxies Tuesday, May 26, 2015
M92 An ancient family of stars Wednesday, May 13, 2015
North Poles Looking north from the Milky Way Saturday, May 9, 2015
Orion Arm A short “arm” of the Milky Way Wednesday, February 18, 2015
Winter Milky Way Looking toward the galaxy’s outskirts Tuesday, February 17, 2015
Survivor The heart of the galaxy stays quiet Monday, January 12, 2015
Distant Neighbors The Milky Way’s lonely outskirts Wednesday, December 17, 2014
Distant Hub Looking into the past of our home galaxy Tuesday, September 30, 2014
WIMP-y Glow Bright evidence of dark matter Wednesday, July 30, 2014
Dark Center Darkness in the heart of the galaxy Tuesday, July 29, 2014
The Brick Building a future stellar nursery Monday, July 28, 2014
Galactic Track A roller-coaster ride around the galaxy Sunday, July 27, 2014
Sagittarius A steaming teapot in the southern sky Thursday, July 24, 2014
Magellanic Collision New stars from a galactic collision Tuesday, July 15, 2014
Magellanic Clouds A new view of two close neighbors Monday, July 14, 2014
North Galactic Pole Gazing away from the Milky Way Saturday, April 12, 2014
Runaway Stars Stars that are leaving home in a hurry Friday, April 11, 2014
Moon in the Middle Bright stars packed around the Moon Saturday, April 5, 2014
Spring Milky Way The Milky Way brackets the night sky Friday, March 28, 2014
Galactic Archaeology Digging into the history of the galaxy Monday, March 24, 2014
Gaia II Mapping a billion stars Friday, October 4, 2013
Local Arm Wrapping our arms around our home galaxy Wednesday, September 4, 2013
Counting Stars Counting the stars in the Milky Way Friday, July 26, 2013
Black Hole Beacon A black hole announces its presence Thursday, July 25, 2013
Galactic Bubbles Keeping food from a black hole Wednesday, July 24, 2013
Good Neighborhood A good neighborhood for young stars? Tuesday, July 23, 2013
Sagittarius A teapot in the southern sky Monday, July 22, 2013
The Antennae Seeing the future of the Milky Way Tuesday, April 16, 2013
Groombridge 1830 An interloper from a distant realm Sunday, March 31, 2013
Milky Way Matters The Milky Way bulks up Saturday, February 9, 2013
M2 A distant home for old stars Sunday, January 6, 2013
Star Populations Segregating the stars of the Milky Way Monday, December 3, 2012
Collision Course Taking aim at another galaxy Wednesday, September 12, 2012
Andromeda Galaxy A galactic twin in the evening sky Tuesday, September 11, 2012
Arcturus Tracing a star’s origins Tuesday, August 28, 2012
Pipe Nebula Lighting up a dark nebula Sunday, June 17, 2012
Future Neighbor A future close neighbor to the Sun Thursday, June 14, 2012
‘Milky’ Way The “milky” band of the Milky Way Sunday, June 10, 2012
Hercules Cloud Piling up stars in the outer galaxy Thursday, May 24, 2012
Cosmic Clocks The ticking of cosmic clocks Thursday, April 12, 2012
Snack Time Snack time for a giant black hole Thursday, March 29, 2012
Alien Clusters Alien visitors from other galaxies Friday, March 23, 2012
Galactic Streams Blending into the Milky Way Thursday, March 22, 2012
Sagittarius Dwarf A galactic tug-of-war Wednesday, March 21, 2012
Satellite Galaxies Satellite galaxies for the Milky Way Tuesday, March 20, 2012
Winter Milky Way III Getting armed for a trip through the galaxy Friday, February 17, 2012
Winter Milky Way II Enlivening the galactic suburbs Thursday, February 16, 2012
Winter Milky Way Following a galactic pathway Wednesday, February 15, 2012
Alpha Persei Cluster Tracing a galactic cataclysm Sunday, October 9, 2011
Robert Trumpler Filling the space between the stars Sunday, October 2, 2011
Milky Way’s Heart V Youngsters at the heart of the Milky Way Friday, September 30, 2011
Milky Way’s Heart IV The flashy heart of the Milky Way Thursday, September 29, 2011
Milky Way’s Heart III Confirming the dark heart of the Milky Way Wednesday, September 28, 2011
Milky Way’s Heart II A sky-spanning marquee of stars Tuesday, September 27, 2011
Milky Way’s Heart Taking a peek at a busy downtown Monday, September 26, 2011
Thomas Wright Giving birth to a galaxy Wednesday, September 21, 2011
M2 An ancient family of stars Saturday, September 17, 2011
Future Skies The universe in the year one trillion Tuesday, August 30, 2011
Speedy Star Measuring the Milky Way with a single star Friday, February 18, 2011
Winter Milky Way The bright and dark Milky Way Sunday, January 30, 2011

Featured Images

Multi-wavelength view of the center of the Milky Way galaxy
Galactic Hub Thursday, August 13, 2015
Artist's concept of Fermi bubbles
Blowing Bubbles Monday, July 20, 2015
Hubble Space Telescope view of the core of M13, a globular cluster in Hercules
Old Sparklers Tuesday, May 12, 2015
G2 survives its swing around the black hole at the center of the Milky Way
Narrow Escape Friday, March 27, 2015
The Milky Way galaxy's spiral arms
Arming the Milky Way Wednesday, February 18, 2015
Artist's concept of hot gas funneling toward black hole at center of Milky Way
Dark Center Tuesday, July 29, 2014
A view of the busy Milky Way
Busy Galaxy Thursday, July 24, 2014
The Milky Way glows above the Nevada desert
Dig Site Monday, March 24, 2014
Artist's concept of the Milky Way galaxy and its dark matter halo
Illuminating the Darkness Saturday, February 9, 2013
Multispectral view of giant star-forming regions at the center of the Milky Way
Molecule Factory Tuesday, November 13, 2012
Andromeda and the Milky Way head for a galactic pile-up
Collision Course Wednesday, September 12, 2012
Artist's concept of stars and a gas cloud near the Milky Way's central black hol
Snack Time Thursday, March 29, 2012
Two globular clusters; a previously known one at right, and a new one in circle
Star City Wednesday, October 19, 2011
Stars and gas swirl around the black hole at the center of the Milky Way
Swirling Center Tuesday, September 27, 2011
Artist's concept of a free-floating planet in the Milky Way galaxy
Free Agent Thursday, May 19, 2011
Cold Fingers Friday, March 19, 2010


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