Astronomers find life's building blocks in a star's nursery

Astronomers find life's building blocks in a star's nursery

Astronomers have discovered an organic molecule, a potential building block for life, within the cold gas cloud of a star that hasn't even been born yet. The finding suggests that the raw ingredients for biology may be seeded into planetary systems from their very inception.

The team, led by astronomer Yuxin Lin, detected the molecule methanimine scattered throughout a dense pre-stellar core called L1544. This cloud, located 554 light-years away in the Taurus Molecular Cloud, is a future star-and-planet system in waiting.

Methanimine is a crucial chemical stepping stone

Methanimine (CH2NH2) is a relatively simple organic molecule. It is a key intermediate in the chain of chemical reactions that can transform basic atoms into complex amino acids, which are the molecules that combine to form proteins.

Astronomers have previously found it in extreme environments, from the hot cores of newborn stars to frigid interstellar ice. Its presence in a quiet, cold pre-stellar core is particularly significant for understanding how planetary systems get their starter kit for chemistry.

• It contains carbon, hydrogen, and nitrogen—three fundamental elements for life.
• It represents a halfway point between raw atoms and complex biomolecules.
• Finding it in a star's nursery means these ingredients are present before planets form.

The cloud is calm before a stellar storm

L1544 is part of a turbulent star-forming region, but it is currently in a remarkably quiescent state. Material is slowly drifting inward from its warmer outer edges toward an ultra-cold, dense center, but it has not yet begun the violent collapse that will ignite a new star.

This slow, cold environment is where the chemistry is happening. The researchers found that methanimine is forming in the cloud's warmer outer layers. As this material rains inward, it distributes the molecule across the entire pre-stellar core.

Molecules will be inherited by future planets

The process ensures that organic precursors like methanimine will be present right up to the moment of stellar collapse. They will then be incorporated into the swirling disk of gas and dust that surrounds the newborn star, from which planets will eventually coalesce.

"This demonstrates that key prebiotic nitrogen and carbon chemistry remains active even in the cold, quiescent phase preceding collapse," Lin and colleagues wrote. This guarantees that these organic precursors "can be inherited by the next generation of forming stars and planets."

If habitable worlds form in such a system, they may already contain the basic chemical ingredients needed for life to arise. The team published its findings in The Astrophysical Journal Letters.