NASA
Nasa: Spitzer Science Center: Story of Stellar Birth
Under the heading, "Story of Stellar Birth" this site examines specific details of an image displaying the apparent life cycles of young stars in the Cepheus constellation.
Khan Academy
Khan Academy: Activity: This Threshold Today
An activity for students to make connections between the universe during threshold 2 and the universe today. Students will learn that there are similarities in conditions that existed during threshold 2 with conditions that exist today.
California Institute of Technology
Spitzer Science Center: Towering Infernos
The "Towering Infernos" in the image at this site are actually nebulae or star-forming regions. The text under the image details the specifics of the picture.
California Institute of Technology
Nasa: Chaotic Star Birth
The Chaotic Star Birth image is part of a series of photographs taken from the Spitzer Space Telescope. The picture is accompanied by a textual overview of a groups of stars being born with specific attention given to the details of the...