In which types of galaxies are you likely to find cool gas and dust, and star formation?

Put the layers of the Earth in order from the inner regions to the outer regions.

The Celestial Sphere model was not sufficient to predict the motions of some objects in the sky correctly. Which category of object did the Celestial Sphere model fail to predict cortrectly?

Which of the following is NOT a reason to conclude that there is a supermassive black hole at the center of the galaxy?

Pulsars were discovered by their radio emission

This type of active galaxy has two different appearances. Which one we see depends on whether we are looking perpendicular to its jets or along the jet.

Globular clusters are

In the 1960’s, astronomer Vera Rubin analyzed data and concluded that the Milky Way was surrounded by what she called “dark matter”. What observational theory led her to this conclusion?

Time speeds up as you approach a massive, dense object like a neutron star or black hole.

The gravity of a black hole is so strong not even light can escape.