Building planets from crystals?

Nasa"â„¢s Spitzer Space Telescope detected quartz-like crystals called cristobalite in young planetary systems. Cristobalite, shown here in this magnified view. Image credit: George Rossman/Caltech
Date:31 December 2008

It starts with crystallised grains of dust. It ends with… Us.

Shock waves around dusty, young stars might be creating the raw materials for planets, according to new observations from Nasa’s Spitzer Space Telescope. The evidence comes in the form of tiny crystals. Spitzer detected crystals similar in make-up to quartz around young stars just beginning to form planets. The crystals, called cristobalite and tridymite, are known to reside in comets, in volcanic lava flows on Earth, and in some meteorites that land on Earth. Astronomers already knew that crystallised dust grains stick together to form larger particles, which later lump together to form planets. But they were surprised to find cristobalite and tridymite. What’s so special about these particular crystals? Well, they require flash-heating events, such as shock waves, to form. The findings suggest that the same kinds of shock waves that cause sonic booms from speeding jets are responsible for creating the stuff of planets throughout the Universe.