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Stars, planets, comets, and nebulas are made of the same atoms we see on Earth: the same periodic table seems to govern all ordinary matter, everywhere. Astrochemistry is the way for researchers to study how those atoms react with each other across wildly different environments, producing both familiar and exotic molecules. Those molecules constitute the dust that makes planets, and organic compounds that are the precursors to life.

Our Work

Center for Astrophysics | Harvard & Smithsonian astronomers and astrochemists study the chemistry of astronomical objects in a variety of ways:

  • Detecting organic molecules in interstellar space. These molecules are often very complex, so finding and characterizing them is important for describing the chemistry of the region between stars — including the raw materials for building new stars and planets.
    GBT Detection Unlocks Exploration of 'Aromatic' Interstellar Chemistry

  • Tracing the origins of molecules in the Solar System and beyond. Some molecules may have formed with the Solar System, but others may have come from earlier chemical processes. Comets and asteroids are relatively pristine relics of the early days of the Solar System, so studying their chemistry and comparing it with the chemical makeup of newly forming star systems helps us learn which is which.
    Astronomers Discover Traces of Methyl Chloride around Infant Stars and Nearby Comet

From Very Small to Very Large and Back Again

Quantum physics tells us that every atom and molecule has a distinct spectrum of light emission and absorption, based on interactions between the electrons and nuclei. By studying the colors of light produced and absorbed by stars, nebulas, and other astronomical objects, astronomers have learned they are made up of the same stuff as matter on Earth.

Environments across the universe can be radically different than Earth, though. Chemistry takes place at very hot or cold temperatures, under huge pressures or low densities, in the presence of intense radiation from stars or inside dark nebulas. As a result, astrochemists study the way chemical bonds form under interstellar conditions which are very alien to us, using astronomical observations, theoretical calculations, and laboratory experiments.

One particular area of interest is the formation of organic molecules, which are compounds including the element carbon. Beyond its essential role in all known life, carbon is one of the most common elements in the universe, and it forms molecules with many other elements. In interstellar space, carbon is the main ingredient of dust: aggregates of molecules that form wispy clouds. Dust is an important component of new stars and planets; knowing how it forms and behaves is necessary for understanding our own origins, as well as other planets.

Astrochemistry also plays a role in studies of the atmospheres of stars and planets. Current and upcoming observatories are designed to detect the chemical elements making up planetary atmospheres, looking for molecules like water and carbon compounds.


drawing of organic molecules discovered in interstellar space

Artistic depiction of polycyclic aromatic hydrocarbons (PAHs), complex organic molecules discovered in an interstellar cloud. These molecules provide a connection between astrochemistry and similar molecules common on Earth.

B. McGuire, B. Saxton (NRAO/AUI/NSF)