Question

Which feature is used to classify galaxies?

age
color
shape
size

Answer 1

The feature most commonly used to classify galaxies is **shape**. Galaxies are typically categorized into different types based on their morphological characteristics, such as spiral, elliptical, and irregular shapes. However, other features like color, size, and age can also provide additional information about galaxies, but shape is the primary criterion for classification in the Hubble sequence.