This is the Carina Nebula, an interstellar cloud of dust, hydrogen, helium and other ionized gases. It lies within our own Milky Way galaxy, about 6,500-10,000 light-years from Earth. Like many nebulae, it is a star-forming region, and contains two of the most massive and luminous stars in our galaxy, along with multiple O-type stars. Our galaxy itself is estimated to contain 200-400 billion stars, and roughly ten times as many planets.
Jewel of the southern sky, the Great Carina Nebula, also known as NGC 3372, spans over 300 light-years, one of our galaxy's largest star forming regions. Like the smaller, more northerly Great Orion Nebula, the Carina Nebula is easily visible to the unaided eye, though at a distance of 7,500 light-years it is some 5 times farther away.
This is probably the most amazing photo you will see of the Orion nebula's center, a cloud of gas and dust known as M42. The work was created by Adam Block at the Mount Lemon Sky Center observatory in Arizona. Image: Adam Block/Mount Lemmon SkyCenter/University of Arizona