Milky Way - History, Structure Of The Milky Way, Formation Of The Milky Way, Nucleus Of The Milky Way
constellations fuzzy band sky
On a clear, moonless night, away from the bright lights of the city, the Milky Way is visible—a fuzzy, milky band stretching across the sky. The Milky Way is the plane of our galaxy, a vast spinning carousel of a few hundred billion stars. Our solar system is located about half way between the center and the edge of this 120,000-light-year diameter pancake shaped galactic disk. The "visible" Milky Way is simply the light from billions of faint stars blending into a fuzzy band across the sky.
In the northern hemisphere summer, the Milky Way passes through the constellations Scorpius and Sagittarius in the south and heads north through Aquila and Cygnus. In winter, the Milky Way slips between the hunting dogs, Canis Major and Minor, over the head of Orion the hunter, and through the feet of Gemini, the twins. In spring and summer, the Milky Way passes through the constellations Cassiopeia and Perseus.
Additional Topics
In the minds of the ancient Greeks, the Milky Way clashed with the perfection expected in the heavens, and as such they thought it had to be an atmospheric phenomenon. The first hint of the true nature of the Milky Way came in 1610 when Galileo examined it with his telescope, and realized that the Milky Way was composed of an uncountable number of faint, individual stars. In 1785, the musician tur…
The problem we face trying to deduce the structure of the Milky Way from our location within it is analogous to the problem faced by the Amazon Indians trying to map the rain forest while confined to its boundaries: it is simply too vast. To map the rainforest today we can simply fly over it in a plane; we cannot yet fly out of the galaxy in a spaceship to map its structure. We must find other met…
The nucleus and halo of our galaxy contain older stars from the first batch to form. The globular clusters in the halo are anywhere from 10 to 17 billion years old and are among the oldest objects in the galaxy. These older stars are called population II stars. The disk and spiral arms consist of younger, second to third generation stars (population I) as well as interstellar gas and dust. This di…
What is in the nucleus of the Milky Way? If we look with optical telescopes, we see nothing. The interstellar dust obscures the optical light. The center of the Milky Way does, however contain very strong sources of radio waves, infrared light, and x rays. One such source, called Sagittarius A*, appears to lie at the precise center of the galaxy, the point about which the entire system rotates. Th…
Citing this material
Please include a link to this page if you have found this material useful for research or writing a related article. Content on this website is from high-quality, licensed material originally published in print form. You can always be sure you're reading unbiased, factual, and accurate information.
Highlight the text below, right-click, and select “copy”. Paste the link into your website, email, or any other HTML document.
User Comments