The Milky Way from above

Imagine that you are looking at the Milky Way from another galaxy. No spacecraft can travel beyond our galaxy, so we can’t take an actual photo. Fortunately, the Gaia mission is creating the most accurate multi-dimensional map of the Milky Way, giving astronomers the data to infer what it would look like.

Gaia’s sky maps – in all three spatial coordinates (3D) plus three velocities (moving towards and away from us, and across the sky) – have revealed the precise motions and positions of millions of nearby stars. With this, the telescope has already revolutionised our view of the solar neighbourhood, allowing scientists to comprehensively map the stars and interstellar material near the Sun in a way they were unable to do before.

“Gaia provides the first accurate view of what our section of the Milky Way would look like from above,” explains Lewis McCallum, astronomer at the University of St Andrews, UK, and first author of two scientific papers explaining the new 3D model.

“There has never been a model of the distribution of the ionised gas in the local Milky Way that matches other telescope’s observations of the sky so well. That’s why we are confident that our top-down view and fly-through movies are a good approximation of what these clouds would look like in 3D.”

Lewis’s new map includes 3D views of the Gum Nebula, the North American Nebula, the California Nebula, and the Orion-Eridanus superbubble. It allows us to fly around, through, and above these areas containing stellar nurseries.