If someone had been around to see it, this is what our Solar System probably looked like when it was only a million years old (for the record, it’s nearly 4.6 billion now, and counting). This image was taken by the giant ALMA telescope, located in the high desert of northern Chile, which sees in radio wavelengths. The detail here is far greater than anything even the Hubble could achieve.
The glowing disk is dust and gas whirling around the young star, known as HL Tauri, located about 450 light-years from Earth in the constellation Taurus. The dark gaps are almost certainly places where the gravity of newly forming planets has swept the dust clean — exactly as Earth, Mars and the other planets in our mature Solar System did long ago. It’s a strong clue that our theories of how planets form are very much on the right track.