Amber Reed's Quiz

What does our galaxy look like?
Our galaxy consists of a disk of stars and gas, with a bulge of stars at the center of the disk, surrounded by large spherical halo.

How do stars orbit in our galaxy?
Stars in the disk orbit in circles going in the same direction with a little up and down motion. Also, orbits of halo and bulge stars have random orientations.

How is gas recycled in our galaxy?
Gas from dying star mixes new elements into the interstellar medium, which slowly cools, making the molecular clouds where stars form. Those stars will eventually return much of their matter to interstellar space.

Where do stars tend to form in our galaxy?
Active star forming regions contain molecular clouds, hot stars and ionization nebulae .Much of the star formation in our galaxy happens in the spiral arms. 

What do halo stars tell us about our galaxy's history?
Halo stars are all old, with a smaller proportion of heavy elements than disk stars, indicating that the halo formed first.

How did our galaxy form?
Our galaxy formed from the huge cloud of gas, with the halo stars forming first and the disk stars forming later, after the gas settled into a spinning disk. 

What lies in the center of our galaxy?
Orbits of the stars near the center of our galaxy indicate that it contains a black hole with 4 million times the mass of the Sun.

Who is Andrea M. Ghez?
She is an American astronomer and professor in the Department of Physics and Astronomy at UCLA.

Who observed stars moving close to the speed of light in the center of our galaxy?
Andrea M. Ghez
Where was Dr. Ghez born? 
She was born in New York City on June 16 1965.