Fly me to the moon...

It wasn't easy, bringing the stars indoors. The world's first planetarium opened 100 years ago, in Germany. It used the grainy imagery of the time, but elicited gasps nonetheless. Today, planetariums invite viewers to zoom through galaxies, tour clouds of asteroids, view meteors as they approach. And, a new future looms: explorations of tech, biology, even the human body - on domes so large and crystal-clear, they're helping astrophysicists learn about space

- Anesha George

It's 1925, and a small crowd has stepped into a pitch-black dome and heard the doors close behind them.

As they struggle to adjust to the darkness, the roof seems to disappear. An expanse of star-studded sky appears above them.

There are no models of ringed globes in this planetarium. No pinholes in the walls, with light shining through to mimic stars. Instead, there is a hub in the centre of the room, throwing out imagery of a dazzling night sky.

"It matters not whether the audience be made up of children or adults, professional people or laymen, the emotional experience is always the same," astronomer George Clyde Fisher wrote, in an essay in the journal Popular Astronomy. "When... the stars are 'turned on,' the audience gasps audibly... No one is prepared for anything so realistic and so dramatic."

Today's planetariums map swirling galaxies, zoom through clouds of asteroids, and add imagery of real meteors as they approach. We'll get to some of those in a bit. First, a look at why things changed, 100 years ago.

It all began with a German electrical engineer named Oskar von Miller, in 1913. von Miller was a busy man. Amid the race for electrification (which picked up pace in the 1880s), he had helped electrify major German cities. A passionate educator, he helped set up the Deutsches Museum in Munich in 1903, a rare institute dedicated to the history of science and technology, and served as its first director.

A decade on, artificial light and rising pollution levels had started to blot out the night sky. In an era of great strides for science, von Miller wondered, was there something he could do to bring people closer to the stars?

He reached out to the optics factory Carl Zeiss, makers of some of the world's best optical instruments since the 1840s. Could they make a machine that could project, indoors, real imagery of the night sky?