Protoplanetary disks are the source of planet formation, but until now we've only seen them as fuzzy blobs, or in artistic renderings. But in a new image from ALMA (the Atacama Large Millimeter/submillimeter Array), we see the disk left behind after a star birth in stunning new clarity.
Stars form when gas and dust are crushed together by gravity. The leftover particles gather around the new star, forming the concentric disks you can see in the image above. Over time, these tiny particles group together to form rocks, and eventually asteroids — and even planets — can be born from the dust.
Observing protoplanetary disks is important for obvious reasons: The closer we get to watching a planet actually being born, the better we'll understand our own planet's origins.
This particular disk surrounds a young star named HL Tau, located around 450 light years from Earth in the constellation Taurus. The incredible resolution of the image is impressive, but we could see ALMA's images get even more focused.
ALMA, which is run as an international partnership between Europe, North America and East Asia, is a telescope made up of 66 high-precision antennas that can be moved into different configurations. These antennas capture radio waves from space, and when their data is combined, they can create images with five times the resolution of the Hubble Space Telescope.
But while ALMA is close to its final configuration, it's not quite running at its maximum resolution yet. Researchers spaced the antennas as much as 15 kilometers apart to get the image above. In earthly terms, this configuration would allow the telescope to take a shot of a penny from 110 kilometers away.
In the near future, the satellites will be moved another full kilometer apart — further increasing the resolution.