Spiral Galaxy Messier 101 in High-Definition from Hubble

This Hubble Space Telescope image of the face-on spiral galaxy Messier 101 (M101) is one of the largest and most detailed views of a spiral galaxy that has ever been released from Hubble. This galaxy's portrait is actually composed of 51 individual Hubble images, in addition to elements from images from ground-based photos (visible near the edges of the image).

The galaxy's spiral arms are sprinkled with large regions of star-forming nebulae. These nebulae are areas of intense star formation within giant molecular hydrogen clouds. Brilliant young clusters of hot, blue, newborn stars trace out the spiral arms.

M101 (also nicknamed the Pinwheel Galaxy) lies in the northern circumpolar constellation, Ursa Major (The Great Bear), at a distance of 25 million light-years from Earth. The galaxy fills a region in the sky equal to one-fifth the area of the full moon.

The final color image was assembled from individual exposures taken through blue, green, and red (infrared) filters.

See http://hubblesite.org/news_release/news/2006-10