The raw ingredients for planets could be created by supersonic shock waves around young stars, a new study to appear in the Astrophysical Journal suggests.
NASA's Spitzer Space Telescope recently examined five baby solar systems with planets just beginning to form.
The observations revealed the presence of tiny quartz crystals that can only form after flash heating followed by rapid cooling, conditions that scientists think could be the result of shock waves of pressure, akin to those from jets that cause sonic booms.
The quartz crystals Spitzer found, called cristobalite and tridymite, are some of the building blocks of planets. During the early stages of planet formation, dust grains in the pancake-like disks of dust and gas surrounding young stars crystallize and stick together, eventually snowballing to form a planet.
Shock waves might arise when clouds of gas swirling around these planet-forming disks collide at high speeds. And this, scientists say, could jump start the process of birthing planets.
"By studying these other star systems, we can learn about the very beginnings of our own planets 4.6 billion years ago," astronomer William
Forrest of the University of Rochester who led the research, said in a release. "Spitzer has given us a better idea of how the raw materials of planets are produced very early on."
In fact, the observations of these star systems about 400 light-years away agree with findings in our own neighborhood. Ancient meteorites that fell to Earth have been found to harbor round grains called chondrules. These pebbles also require special circumstances to form, and shock waves in our solar system’s early disk could be responsible.
Image: NASA/JPL-Caltech
