Blooming IrisSpring flowers are blooming—even in space. This recently released picture shows NGC 7023, also called the Iris nebula for its floral appearance, as seen from Kitt Peak National Observatory in Arizona.The cosmic flower is actually what's known as a reflection nebula. The interstellar cloud of dust and gas glows not because its material is being heated, but because it's reflecting light from nearby stars.For instance, the bright glow in the middle of the nebula comes from a hot, massive star that gives off blue light, which then gets scattered by dust, lending the nebula its distinctive color.
Image courtesy T. A. Rector/UAA, H. Schweiker/WIYN, and NOAO/NSF

Space Pictures This Week: Cosmic Flower, Inside-Out Star

An "iris" blooms among the stars, auroras paint Norway, a supernova gets mapped, and more in the week's best space pictures.

April 7, 2012