Galaxies through time. 

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Telescopes allow us to see very far away. And also to see light that was emitted long ago, which is like looking back in time. By viewing the universe at different distances and eras we have evidence that galaxies change over time. They grow, collide and merge with each other, and form new stars. The most distant, earliest galaxies we have seen tend to be smaller and less structured than those in the nearby universe. 

How did galaxies evolve over billions of years? From the early universe to the era of our own Milky Way, how can we learn about the forces that drive this change? Using images of many different galaxies throughout the history of the universe astronomers can assemble something like a galactic flipbook. Patterns emerge. Some eras were big for mergers and new star formations, while during others astronomers see trends for growth into larger galaxies with supermassive black holes at their centers. 

Together, these images provide an outline of the average galaxy story. However, the opening chapters are still blank. This is because the universe is expanding. And as space itself stretches, so does the wavelength of the light from the first galaxies. Putting them beyond the detection of our most powerful telescopes. 

The story of the universe and its galaxies is like other stories, if you miss the beginning you lose a lot of understanding. Seeing the light of the first galaxies provides a more complete picture of galaxy evolution. NASA's James Webb Space Telescope was specially designed to detect the ancient, stretched light from the first galaxies. Webb will fill in the blank pages in the flip book of galactic history and examine the middle eras in new detail. Providing essential insight into some of our biggest questions. How does the universe work? And how did we get here?