Hubble’s 100,000th Pass Showcases Star Birth
Battling "Cellular Littering" Critical for a Longer Life

Video Tour of the Andromeda Galaxy

Andromeda, a spiral galaxy approximately 2.5 million light-years away in the constellation Andromeda is the nearest spiral galaxy to our own, the Milky Way. Andromeda and the Milky Way are approaching one another at a speed of 100 to 140 kilometers per second (62–87 miles/sec). However, this does not mean it will definitely collide with the Milky Way, since the galaxy's tangential velocity is unknown. If they do collide, the two galaxies will likely merge to form a monster elliptical galaxy.

Andromeda, home to the evil Kelvans in an early Star Trek episode, was believed to be the largest galaxy of the Local Group of galaxies, which consists of the Andromeda Galaxy, the Milky Way Galaxy, and the Triangulum Galaxy, and about 30 other smaller galaxies. But scientists now believe that the Milky Way contains more dark matter and may be the most massive in the grouping. 

However, recent observations by the Spitzer Space Telescope revealed that Andromeda contains one trillion stars, greatly exceeding the four billion stars in our own galaxy. The wide, detailed Spitzer Space Telescope view of Andromeda at the top of the page features infrared light from dust (red) and old stars (blue).

This X-ray image, made with the Chandra X-Ray Astronomy Center's Advanced CCD Imaging Spectrometer, shows the central portion Andromeda. The Chandra X-ray Observatory is part of NASA's fleet of "Great Observatories" along with the Hubble Space Telescope.

M31cxo The blue dot in the center of the image is a "cool" million degree X-ray source where Andromeda's massive central object, with the mass of 30 million suns, is located, which many astronomers consider to be a super-massive black hole. Most of these are probably due to X-ray binary systems, in which a neutron star (or perhaps a stellar black hole) is in a close orbit around a normal star.

Posted by Casey Kazan.


Great, beautiful, insipring and amazing. It's just the beginning of what we know. Where we go from here only GOD knows.

This is not the andromeda galaxy. It is our galaxy the milky way you morons.

No, it is the Andromeda according to the text. The colour choices are arbitrary, I think, but it makes a glorious show, doesn't it?
Thanks so much for this, it's inspiringly beautiful and much more an expression of the brilliance of homo sap. than any more nebulous entity.

I believe there is a typo error. The Milky way galaxy has 400 billion stars not 4 billion has stated in this article. If the super massive black hole in the Andromeda galaxy is 30 million solar masses versus 4 million of Sagittarius A in the milky way then Andromeda is still a bigger galaxy.

Verify your Comment

Previewing your Comment

This is only a preview. Your comment has not yet been posted.

Your comment could not be posted. Error type:
Your comment has been posted. Post another comment

The letters and numbers you entered did not match the image. Please try again.

As a final step before posting your comment, enter the letters and numbers you see in the image below. This prevents automated programs from posting comments.

Having trouble reading this image? View an alternate.


Post a comment

Your Information

(Name is required. Email address will not be displayed with the comment.)