M20

The beautiful Trifid Nebula is a cosmic study in contrasts. Also known as M20, it lies about 5,000 light-years away toward the nebula rich constellation Sagittarius. A star forming region in the plane of our galaxy, the Trifid illustrates three different types of astronomical nebulae; red emission nebulae dominated by light emitted by hydrogen atoms, blue reflection nebulae produced by dust reflecting starlight, and dark nebulae where dense dust clouds appear in silhouette. The bright red emission region, roughly separated into three parts by obscuring dust lanes, lends the Trifid its popular name. But in this sharp, colorful scene, the red emission is also surrounded by the the telltale blue haze of reflection nebulae. Pillars and jets sculpted by newborn stars, below and left of the emission nebula's center, appear in Hubble Space Telescope close-up images of the region. The Trifid Nebula is about 40 light-years across.

This object was one of the first things I saw as a child looking through a book on astronomy. Of course that book was printed in the 60's or early 70's so the images were a lot less clear and detailed. But I remember looking at the picture and just wondering what else was in space. That got me started down the road to study astronomy in college. It is still fascinating to see these images, though now when I look at the picture I see the physics involved and understand the processes that are shaping these interesting objects in the sky.