If you were in an unfamiliar city, and they showed you a map of that city with no other directions, would you be able to indicate your location?

The answer can only be NO, unless you owned a lot of other information, such as the street name or the proximity of particular, immediately recognizable monuments or buildings.

We encountered the same difficulty when, decades ago, we inhabitants of planet Earth set out to figure out what the position of our solar system is within the framework of our host galaxy: the Milky Way.

You know those cute little cartoons with a galaxy drawn, an arrow pointing to a spot … and the words,

You are here? Here–since the beginning of the last century, astronomers have been working hard to succeed in doing something like that.

Putting an arrow on the image of the Milky Way to answer the question, What is our place in the universe?