Where Do Stars Come From? Space 'Yellow Balls,' Of Course

 (CBS) –  Where do stars come from? You might say they start out as yellow balls.

At least that is the name given to star cocoons spotted by volunteers who combed through infra-red photos of the Milky Way.

Adler Planetarium Astronomer Grace Wolf-Chase says the yellow space balls are an important step in star formation.

First come great dark clouds of gas that clump into filaments of very young stars. Then come the yellow space balls -- cocoons incubating the young stars -- and lastly come the giant expanding clouds of green gas blown off by the new stars.

Wolf-Chase says the Adler Planetarium and Oxford University jointly run "Zooniverse," whose volunteers examined thousands of infra-red photographs from the Spitzer Space telescope to discover the yellow space balls.

The space balls appear small in the photos but are actually thousands of times larger than our own solar system.

So far, volunteers have found 900 of these yellow space balls, as part of the Milky Way project.

In:
• Dallas Stars
• Adler Planetarium
• John Cody