Table of Contents
What is the evidence that we live in a spiral galaxy?
The concentration of stars in a band adds to the evidence that the Milky Way is a spiral galaxy. If we lived in an elliptical galaxy, we would see the stars of our galaxy spread out all around the sky, not in a single band.
Is our sun located on one of the spiral galaxy arms?
Orion Arm
Bottom line: The sun is about 1/3 the distance from the center of the Milky Way galaxy to its outer edges. It’s located in a smaller spiral arm, between two large arms, called the Orion Arm.
How did humans determine the shape of the Milky Way galaxy?
We can’t travel outside the galaxy to take pictures. A space probe moving at near light speed would take thousands of years to get far enough away to take a parting snapshot. But we can infer the shape of our galaxy by looking outward into space – toward tens of billions of other galaxies.
What evidence supports the existence of a very massive black hole at the center of our Galaxy?
What evidence supports the existence of a black hole at the center of our galaxy? The motions of the gas and stars at the center indicate that it contains 4 million solar masses within a region only 3 light-years across. What is the most common form of gas in the interstellar medium? What is a shock wave?
How did astronomers determine where Earth is located within the Milky Way?
The Earth’s place in the galaxy was determined largely by an astronomer named Harlow Shapley. Thanks to the regular periods of these stars and their presence in globular clusters, Shapley was able to map the distances to a number of clusters.
How do we know the shapes of galaxies?
The clues we have to the shape of the Milky Way are: 1) When you look toward the Galactic Center with your eye, you see a long, thin strip. This suggests a disk seen edge-on, rather than a ellipsoid or another shape. 3) The gas fraction, color, and dust content of our Galaxy are like other spiral galaxies.