Stellar nurseries carry the stuff of life, long before stars

Organic compounds in nearby protostellar clouds point to star-planet evolution.

Miguel Adrover


ESA/Herschel/NASA/JPL-Caltech; R. Hurt (JPL-Caltech), CC BY-SA IGO 3.0

This mosaic of the Taurus Molecular Cloud is made from observations of nearby pre-stellar clouds, located 450 light-years from Earth. Young stars like HL Tauri — about 3 million years old — call these stellar nurseries home. But before the emergence of proper stars, all we have are massive regions of raw gas —

with lifespans of less than a million years. Driven by processes like turbulence and gravitational forces, the gas and dust in the molecular cloud collapses to form filaments, and it is within those filaments that the denser cores form.

Gravity and turbulence behave like cosmic thumbs and index fingers, weaving an intricate network of filaments, teeming with bright clumps: the seeds of future stars. The bright clumps of molecular threads — as long as 1,000 solar systems lined next to each other — are rich in molecules made out of elements that life requires: C, O, & H.

“The basic organic chemistry needed for life is present in the raw gas prior to the formation of stars and planets”

— Yancy Shirley

Volatile organic compounds that invade our noses when we wake up to the smell of coffee — or when we hike through a tropical rainforest, its floor littered with ripe fruit—are common in these molecular clouds. These compounds are methane and acetaldehydes.

“[H]ow precursors to life came into existence, how they migrate and enter solar systems at later stages of star formation”

— Samantha Scibelli

The simplest hydrocarbon, methane, does not require the heat and pressure that stars are famous for. In other words, statements such as Stars as hearths for the stuff of life have to be reviewed in light of these findings, which show an important chapter — or prologue — of the emergence of solar systems:

“Our solar system was born in a cloud like this, but the cloud is not there anymore for us…