WHAT IS ASTROCHEMISTRY? - SCIENCE - 2025

The Astrochemistry studies the composition and reactions of atoms, molecules and ions in space. It is a scientific discipline that combines knowledge of chemistry and astronomy.

Furthermore, astrochemistry investigates the formation of cosmic dust and chemical elements in the Universe by analyzing the electromagnetic radiation of celestial bodies.

Another important topic in astrochemistry is the study of prebiotic organic chemistry in order to understand the origin of life on Earth.

For a long time, man has always felt admiration and curiosity for space: Gods, theories and monuments were attributed to the cosmos with the intention of being able to explain it, something that is currently detailed in depth thanks to this science called astrochemistry.

The main techniques that astrochemists have to carry out the analysis of interstellar matter are radio astronomy and spectroscopy.

How does astrochemistry work?

The first step is to identify an element in space: analogous to the fingerprint, it is possible to identify a chemical element in space thanks to the reflected radiation as a function of wavelength; that is, thanks to its spectral signature (unique and unrepeatable).

Then, this information must be verified: if said spectral signature has already been analyzed in the laboratories using spectroscopy techniques, then the emitting molecule can be identified without problems. Otherwise, it will be necessary to resort to new chemical studies in the laboratories.

Finally, if you want to understand the functioning of the molecule, you must resort to chemical models and laboratory experiments carried out in ultra-high-vacuum chambers. These cameras simulate extreme conditions that exist in the stellar environment, such as:

• Formation of ice on the surfaces of dust grains.
• Aggregation of molecules to dust grains.
• Formation of dust grains in the atmospheres of evolved stars.

All these studies of astrochemistry help to understand the formation of planets, stars and of course, the origin of life on Earth.

Astrochemistry areas

Astrochemistry is a relatively new area, mainly studying molecules (formation, destruction, and abundance) in various environments. These environments can be:

• Planetary atmospheres.
• Kites
• Protoplanetary discs.
• Regions of Star Birth.
• Molecular clouds.
• Planetary nebulae.
• Etc.

Depending on the (physico-chemical) conditions of the environments, the molecules will be in the gas or condensed phase.

Astrochemistry can be divided into three sub-areas, which are:

1. Observational astrochemistry.
2. Theoretical astrochemistry.
3. Experimental Astrochemistry.

1- Observational astrochemistry

Mainly, molecules are observed through the length of radio and infrared waves. In the wavelength of millimeters, many characteristics of ionic and molecular neutral species are found.

For this, equipment is used that achieves high sensitivity and angular resolution, enabling the identification of a large number of molecules and the mapping of prebiotic molecules.

2- Theoretical astrochemistry

The main challenge of theoretical astrochemistry is to incorporate the complexity of the chemical reactions that take place on the surface of dust particles and grains.

Some of the questions studied in theoretical astrochemistry are the following:

• The main chemical reactions at a certain altitude within the atmosphere of a planet.
• The chemical evolution of the molecular cloud as a function of the initial atomic abundances of time.

From the observations, models are developed to describe different chemical or physico-chemical scenarios.

3- Experimental Astrochemistry

Experimental astrochemistry is a multidisciplinary science that investigates the presence, formation and survival of molecules in various environments.

This research is carried out through laboratory experiments, where simple molecules are processed, then forming pre-biotic organic molecules. These experiments involve the gas and condensed phases:

1. Experiments involving the gas phase: Astrophysical environments containing chemical species in the gas phase are simulated, such as the atmosphere of planets, comets and the gaseous component of the interstellar medium.
2. Experiments involving the condensed phase: environments that are at low temperatures are investigated. These temperatures are between ten and one hundred Kelvin (example: dust grains in protoplanetary disks).

In addition to the above, experimental astrochemistry also investigates moons, asteroids, frozen surfaces of planets, etc.

ALMA: the largest astronomical project in the world

Joint ALMA Observatory (JAO) - By ESO / B. Tafreshi (twanight.org) (http://www.eso.org/public/images/potw1238a/), via Wikimedia Commons

The Atacama Large Millimeter / submillimeter Array or ALMA is the largest astronomical project in the world carried out by an international association comprised of North America, Europe and part of Asia in collaboration with Chile.

It is an interferometer (optical instrument) comprised of sixty-six antennas designed to observe millimeter and submillimeter wavelengths; that is, to obtain well-detailed images of planets and stars at birth.

This project was built in Chile (Atacama desert) and although it was inaugurated in March 2013, the first images published by the press were in October 2011.

In summary

This science has its origins in 1963 and since then it has evolved considerably, due to the study of materials collected by rockets, the satellites sent to other planets and the advancement in the field of radio astronomy (study of celestial bodies by means of wavelength).

Through astrochemistry it has been possible to know the chemical composition of many materials in space, which helps to understand the mechanisms of the evolution of planet Earth (and many other planets).

In addition, through astrochemistry, similarities between Earth and other planets were discovered, such as rocky surfaces originated from chemical elements such as Iron and Magnesium.

References

1. Ardao, A. (1983). Space and intelligence. Caracas: Equinox.
2. University of Barcelona. (2003). Physics vocabulary: català, castellà, angles. Barcelona: Servei de Llengua Catalana of the University of Barcelona.
3. Ibáñez, C. & García, A. (2009). Physics and chemistry in the Colina de los Poplar: 75 years of research in the «Rockefeller» building of the CSIC (1932-2007. Madrid: Higher Council for Scientific Research.
4. Wikipedia. (2011). Applied Chemistry: Astrochemistry, Biochemistry, Applied Biochemistry, Geochemistry, Chemical Engineering, Environmental Chemistry, Industrial Chemistry. www.wikipedia.org: General Books.
5. González M.. (2010). Astrochemistry. 2010, from https://quimica.laguia2000.com Website:
6. Wikipedia. (2013). Disciplines of Astronomy: Astrobiology, Astrophysics, Astrogeology, Astrometry, Observational Astronomy, Astrochemistry, Gnomonics, Cele Mechanics. www.wikipedia.org: General Books.