Yesterday, astronomers operating a series of telescopes in South America released a pretty amazing image — the most detailed view we've ever had of a newly forming solar system.
This is a star called HL Tau, 450 light years away from Earth. It's surrounded by a disc of dust and gas, slowly rotating and coalescing into new planets:
(ALMA/ESO/NAOJ/NRAO)
In other words, if you looked at our own solar system a few billion years ago — before Earth or any of the other planets had been formed — this is probably what you would have seen.
Note that this isn't an artist's rendering or illustration — this is an image produced based off radio waves emitted by the system, and collected by an array of telescopes in the desert of Chile.
How solar systems form
An artist's rendering of the star system. (ESO/L. Calçada)
This solar system (like our own) began to form when the force of gravity pulled together ambient gas and dust into a disk. Over time, the huge amount of pressure at the at the center of disk creates a star.
Meanwhile, pieces of material orbiting at various distances gradually coalesce. As they get bigger, the force of their gravity sucks in the dust and gas nearby, forming ever-denser rings of material and carving out empty gaps in between them.
Over the course of millions of years, these rings eventually become a series of planets orbiting the star, and the gaps become the space between them.
With this new image, what we're seeing in detail for the first time is discrete rings of dust and gas. Check back in millions of years, and you'll see a mature solar system.
This video gives you an idea of how far away the new star system is. (ALMA/ESO/NAOJ/NRAO/NASA/ESA/N. Risinger)