Protostars shine in their dusty shrouds in this image of the molecular cloud associated with the Rosette Nebula from the European Space Agency's Herschel spacecraft.

Herschel, built in conjunction with NASA and launched last year, boasts the largest telescope mirror ever launched into space, 3.5 meters in diameter. Like NASA's James Webb Space Telescope, set to be launched in 2014 with an even larger 6.5-meter mirror, Herschel collects infrared light. Visibility in that range of the electromagnetic spectrum, which is greatly reduced on Earth due to atmospheric absorption, allows the observatory to peer at stars being created inside dusty molecular clouds. At the time of its launch, Paul Goldsmith, Herschel project scientist at the NASA Jet Propulsion Laboratory in Pasadena, Calif., told that Herschel's infrared view of star birth would be "analogous to using ultrasound to seeing what is going on in a mother's womb."

In the image above, Herschel reveals star formation in a region of the Milky Way's Rosette Nebula. About 4,500 light-years away in the direction of the constellation Monoceros, the nebula is large enough to be visible through small telescopes; if it were bright enough in the visible spectrum it could be seen by the naked eye, occupying several times as much of the sky as the full moon.