Given the task definition and input, reply with output. Given a scientific passage and an answer, generate a question for the given answer.

Passage: The universe contains all the matter and energy that exists and all of space and time. We are always learning more about the universe. In the early 20th century, Edwin Hubble used powerful telescopes to show that some distant specks of light seen through telescopes are actually other galaxies. ( Figure below ) Hubble discovered that the Andromeda Nebula is over 2 million light years away. This is many times farther than the farthest distances we had measured before. He realized that galaxies were collections of millions or billions of stars. Hubble also measured the distances to hundreds of galaxies. Today, we know that the universe contains about a hundred billion galaxies. Answer: edwin hubble
Who discovered that the andromeda nebula is over 2 million light years away