The Secrets Inside the Ancient Crystals of Long-Dead Stars

Presolar grains are solid minerals, on the scale of nanometers to micrometers, that crystallized in the gassy outflows and ejecta of stars that existed before the Sun was born 4.6 billion years ago .

Only senescent stars make presolar grains; main-sequence stars in the prime of their lives, like the Sun , do not shed enough gas into space to produce solid stardust.

By studying their compositions, scientists can match the origin of these grains to various types of stars.

Presolar grains have survived in much higher concentrations in primitive and unaltered bodies, like asteroids.

They open direct windows into the bellies of bygone stars, the environment of interstellar space, the origin of the solar system, and the evolution of specific bodies within it.

The grains can shed light on a host of open questions that touch on phenomena ranging from atomic to galactic scales.

Presolar grains survive in interstellar space long enough to be integrated into new star systems, like our own.

One compelling mystery is how presolar grains survived long enough in interstellar interstellar space.

“Every time I find a new grain, I get excited, it’s like: This was once a piece of a star!”.