The image shows a face-on galaxy with a bright round core and graceful arms that wind outward through a flat disk, with no straight bar across the center. How is it classified?

A galaxy image shows two spiral arms trailing from the ends of a long, bright, straight core. What class best matches this shape?

The image shows a smooth, oval, yellow-white galaxy with no spiral arms, dust lanes, or clumpy star-forming regions. How should it be classified?

A galaxy in the image looks ragged and clumpy, with scattered star-forming patches but no clear disk, arms, or oval outline. What is its shape class?

An edge-on galaxy image shows a thin glowing disk crossed by a dark dust lane and a bright central bulge. Which class does this evidence support?

A galaxy image shows a nearly round, featureless glow made mostly of old-looking yellow stars, without a flattened disk. What shape class is shown?

The image shows two spiral galaxies linked by a stream of stars as their gravity pulls on each other. If the pull tears both apart into one ragged cloud of stars with no arms or disk, what class will it then fit?

Use the Milky Way diagram. The Sun symbol sits on label C. What structure is label C?

Use the Milky Way diagram. Which broad structure of the galaxy contains the Sun?

Use the face-on Milky Way diagram. Which statement matches the Sun's position?

Use the Milky Way diagram. The Sun lies in three of these structures. Which one does it NOT lie in?

Use the Milky Way structure diagram. What structure is label C?

Our solar system orbits the Milky Way's center while embedded in which named small arm or spur of the galaxy?

A student says a light-year is a unit of time because it contains the word year. What quantity does a light-year actually measure?

The Milky Way's disk is more than 100,000 light-years across. Why do astronomers often use light-years instead of kilometers for galaxy distances?

Proxima Centauri is 4.24 light-years away. When its light reaches a telescope tonight, about how long has that light traveled?

A small galaxy is 80,000 light-years wide. At the speed of light, how long would light take to cross that width?

A telescope image shows a galaxy as it looked 2 million years ago because its light has just arrived. What distance statement follows from that light-time?

From a dark site, the Milky Way appears as a faint, milky band arcing across the sky. What does that appearance show about our location?

Astronomers cannot take a single outside photograph of the whole Milky Way face-on. What is the main reason?

Most stars and dust seen from Earth concentrate near one great circle on the sky called the galactic plane. What Milky Way structure does that pattern support?

Maps of globular clusters show many old clusters above and below the Milky Way's flat disk. Which structure do those clusters help trace?

The Milky Way, Andromeda, and over 50 nearby smaller galaxies are gravitationally associated. What is this neighborhood called?

Galaxy groups and clusters are both held together by gravity. A structure with thousands of galaxies is best called what?

The Local Group is part of a larger cosmic web region that also includes the Virgo Cluster. What larger-scale structure does NASA identify for our region?