When you are lucky enough to be in a place where there is little artificial light on a dark night, you can look out and see millions of stars. This incredible sight is dwarfed if you are lucky enough to go up into space and look out into its depths, where billions of stars and galaxies are visible.

Things were not always like this, though, at least according to a new report from Harvard astrophysicist Catherine Zucker.

This is because at some point between 12 and 15 million years ago, our solar system passed through what is known as the Radcliffe wave. The Radcliffe wave is a massive 9000 light-year-long area that is filled with young stars, gas, and dust.

According to Zucker, while moving through this area of space, far fewer stars would have been visible, and even the light from our sun wouldn’t have been as bright. There would have, however, been other impressive activities going on in space.

Specifically, Zucker told the Washington Post that there was, “…a festival of supernovae going off.”

This claim is further amplified by University of Vienna doctoral student, Efrem Maconi. They used information from the Gaia telescope, which is operated by the European Space Agency.

By looking at stars in the now distant Radcliffe wave, they were able to determine that the wave very likely passed through the area where our solar system was around 14 million years ago.

While 14 million years is a very long time, it is actually quite recent in geological and evolutionary terms. For context, dinosaurs are thought to have gone extinct about 66 million years ago. So, just 14 million years ago, the plants and animals roaming the Earth wouldn’t be too different than what we see today.

He talked about what things living back then may have seen when looking up at the sky in an interview with New Scientist.

“If we are in a denser region of the interstellar medium, that would mean that the light coming from the stars to you would be dimmed. It’s like being in a foggy day.”

Some researchers even believe that this may have caused climate cooling that is believed to have taken place during the Middle Miocene epoch, but that is far from proven at this point.

Whatever the case, it is interesting to remember that our night sky used to look very different, and it may look very different again in the future.

If you thought that was interesting, you might like to read about 50 amazing finds on Google Earth.