Astronomy
Properties and Evolution of Protoplanetary Disks
Quick fact
A protoplanetary disk can contain up to a few percent of the star's mass in gas and dust, and it typically lasts only a few million years—barely a blink in a star's lifetime—yet it is where all planets are born.
Why this is interesting
Every planet in your solar system once lived inside a swirling cloud of gas and dust around the young Sun. How did that chaotic, glowing disc become the ordered family of worlds we orbit today?