Four images of the Whirlpool galaxy (Messier 51, NGC 5194/5195). This is actually a pair of galaxies, located approximately 23 million light-years from Earth in the constellation Canes Venatici. At left is a visible light image from the Kitt Peak National Observatory 2.1-meter telescope. The next image combines two visible-light wavelengths (blue and green) and infrared light (red) from NASA's Spitzer Space Telescope, which illuminates the dark dust lanes. In the third image, three wavelengths of infrared light are shown. The blended light from the billions of stars in the galaxy is brightest at the shorter infrared wavelengths and appears as a blue haze. Dust, mostly composed of carbon, and is illuminated by the stars in the galaxy, is red. At right the infrared view is expanded to include light at a wavelength of 24 microns. The bright reddish-white spots are where new stars are forming and, in the process, heating their surroundings.