An epic journey through cosmic history begins with a simple sketch


This drawing shows what the Museum’s Director of Astrovisualization Carter Emmart, who also directed Dark Universe, envisioned as one of the first stops on the Space Show’s cosmic journey: California’s famous Mount Wilson Observatory. The scene will illustrate the momentous discovery that took place in 1923.

At the time, some astronomers thought that the Milky Way galaxy constituted the entire universe. Over the course of the 19th century, astronomers had observed fuzzy patches in the night sky, which they called nebulae, and theories to explain these findings abounded. Were these images of stars being formed? Patches of lit-up gas? Or galaxies beyond our own? Astronomers set out to find out.


An epic journey through cosmic history begins with a simple sketch

Edwin Hubble was among those astronomers using the 100-inch Hooker Telescope at Mount Wilson. He looked for a type of very luminous star, called a Cepheid Variable, within a bright spiral nebula. Just a few years earlier, astronomers had determined that these types of stars could be used as distance markers. That’s because Cepheid Variable stars brighten and dim in predictable patterns over a number of days; the longer the time between the star’s peaks of brightness, the greater its luminosity. By measuring that period, astronomers can figure out the star’s luminosity and its distance to the Earth.

An epic journey through cosmic history begins with a simple sketch

Once Hubble found a Cepheid Variable star in the spiral nebula, he measured the time between its peak brightnesses to figure out its luminosity and distance from Earth: 1 million light years, more than three times the calculated diameter of the Milky Way at the time. The star was well outside of our galaxy, proving that the universe was a much bigger place than some had thought filled with galaxies beyond our own. Hubble went on to discover other Cepheid Variables in the spiral nebula and refine his measurements of the distance to our neighboring galaxy, now known as Andromeda. This was just the beginning, Andromeda became a gateway for Hubble and other astronomers to further discover the mysteries of vast universe.


Andromeda—and many other locations in our surprising, and ever-expanding universe—appear in Dark Universe in stunning, scientifically accurate visualizations created by Emmart and his team of artists.

An epic journey through cosmic history begins with a simple sketch

Check back next week to see more behind-the-scenes images from the making of Dark Universe.

All images © AMNH/C. Emmart