Answer to Question 1
A galaxy is a great cloud of stars, gas, and dust bound together by the combined gravity of all the matter. In the night sky, you see our Galaxy from the inside as a great, cloudy band of stars ringing the sky as the Milky Way, and our Galaxy is called the Milky Way Galaxy. Astronomers use evidence to guide their explanations as they envision what our Galaxy looks like. Artists can then use those scientific descriptions to create a painting. Our Sun would be invisible in such a picture, but if you could see it, you would find it about two-thirds of the way from the center to the edge.
Answer to Question 2
Our Galaxy contains more than 100 billion stars, and, like many others, has graceful spiral arms winding outward through the disk. Spiral arms are long spiral patterns of bright stars, star clusters, gas, and dust. Stars are born in great clouds of gas and dust as they pass through the spiral arms.
The three stages of a specific immune response.
The elliptical galaxy Centaurus A at visible, far-infrared and x-ray wavelengths.
Ultraviolet mosaic of Mira's bow shock and tail obtained using NASA's Galaxy Evolution Exp
Galaxy
Elliptical Galaxy M32
Dose-Response Curves for Morphine