Ultraviolet radiation from stars, particularly high-energy photons, initiates chemical reactions by breaking molecular bonds and ionizing atoms.

Hydrogen (H2) is the most abundant molecule in the interstellar medium, comprising approximately 90% of its mass.

Chemical evolution refers to the processes by which simple molecules in the interstellar medium combine to form more complex organic molecules, including those essential for life.

Comets are known to contain a diverse range of complex organic molecules, including amino acids, which are the building blocks of proteins.

The detection of complex organic molecules in space has implications for the origin of life on Earth, the possibility of life beyond Earth, and our understanding of the chemical evolution of the universe.

Radiative association is the primary process responsible for the formation of water molecules in space, where a hydrogen atom and a hydroxyl radical combine under the influence of a photon.

Cosmochemistry is the study of the chemical composition of meteorites and other extraterrestrial materials, providing insights into the origin and evolution of the solar system.

The Strecker synthesis is a chemical reaction that is believed to be responsible for the formation of amino acids in space, involving the reaction of an aldehyde or ketone with hydrogen cyanide and ammonia.

Atmospheric chemistry is the study of the chemical composition and reactions occurring in planetary atmospheres, including the interactions between gases, aerosols, and radiation.

Polymerization is the process by which smaller molecules combine to form larger, more complex molecules, and it is believed to be responsible for the formation of complex organic molecules in planetary atmospheres.

Interstellar chemistry is the study of the chemical processes occurring in interstellar clouds, including the formation and destruction of molecules and the role of cosmic rays and ultraviolet radiation.

Ion-molecule reactions are believed to be responsible for the formation of carbon monoxide (CO) in space, where a positively charged ion reacts with a neutral molecule to form a new molecule.

Stellar chemistry is the study of the chemical composition of stars, including the abundance of elements and the processes responsible for their formation and destruction.

Ion-molecule reactions are believed to be responsible for the formation of hydrogen cyanide (HCN) in space, where a positively charged ion reacts with a neutral molecule to form a new molecule.

Geochemistry is the study of the chemical composition and processes occurring in planetary interiors, including the formation and evolution of rocks and minerals.