Edwin Powell Hubble (1889-1953) was a WWI veteran, lawyer, high school teacher and basketball coach. He fulfilled his childhood dream and became an astronomer at Mount Wilson Observatory in Pasadena, Calif., in the 1920s.

His research expanded the frontiers of the known universe.  He measured the distance to Andromeda using a Cepheid star — a star that appears to vary in brightness in a predictable pattern, like a lighthouse beacon. He realized that Andromeda was not a nearby nebula as previously thought but a distant galaxy. Astronomers once thought the Milky Way was the universe. Hubble revealed a universe with billions of galaxies, each containing billions of stars. He also observed that the farther a galaxy is from Earth, the faster it appears to move away. The universe itself has been expanding ever since the Big Bang.

For more than 25 years, the Hubble Space Telescope has expanded our view of the cosmos in the pioneering tradition of Edwin Powell Hubble. HST captured the drama of comet impacts on Jupiter. Astronomers have also learned about planet formation, supermassive black holes, organic molecules on exoplanets and even mysterious dark energy causing the universe to speed up in its expansion.

Telescopes are time machines. We see distant stars not as they are today but as they were when they released the light that has traveled to us. The deeper we peer into the cosmos, the further back in history we are looking. HST has shown us “baby pictures” of the universe by collecting ancient light, arriving from the farthest objects in the universe as they appeared billions of years ago.

Today you can be a citizen scientist and help astronomers pour through Hubble’s massive image archive to learn about galaxy formation. Hop online and classify galaxies by their shape at the Galaxy Zoo.

First Published: July 28, 2016, 4:00 a.m.