The above image is, to me, one of the most astounding astrophotographs in awhile. To the layperson, it may not seem like much, but the photograph is a time machine to four and a half billion years ago, back when our solar system was just a fetus. More succinctly, the photograph comes from the ALMA Observatory, and is a direct image of a protoplanetary disk. A protoplanetary disk is the beginning stages of planet formation around a young star.
Stars condense from interstellar clouds of gas and dust, often from nebulae such as the one in the constellation Orion, along with many other stars. The baby stars will often have an orbiting disk of gas and dust that will collect into clumps and eventually form planets. This was how our own solar system, and the others out there in the universe, formed.
We’ve seen much more vague images of solar system formation in the past, but never in such detail. ALMA captured the image of the disk surrounding the star HL Tau, and what was particularly astonishing about the image is the speed at which planet formation is happening within this solar system, as HL Tau as a star is only a million years old (which, for a star, means it’s umbilical cord was just cut.) Catherine Vlahakis of ALMA spoke about the image, saying,
“HL Tauri is no more than a million years old, yet already its disc appears to be full of forming planets. This one image alone will revolutionize theories of planet formation.”
Images like this will better help us understand our own origins. But, knowledge aside, looking at this image to me is kind of like looking at an ultrasound. It makes me wonder what sort of planets this star will harbor in the future, and what sort of potential comes with them. Will they harbor life someday? Will those planets grow civilizations similar to ours? One can only wonder…