Astrochemistry is an area of science which studies the atoms and molecules in space and the reactions that occur between them. This type of study enables researchers to understand more about how planets and stars are formed. While once it was thought that nothing existed in the spaces surrounding stars and planets, now it is recognized that numerous molecules are to be found. Some of these are familiar on Earth, such as hydrogen, and other chemicals only exist in space. It is thought that astrochemistry research into the behavior of molecules in space could provide clues to the origins of life on Earth.
Early astronomers used telescopes which could only see objects that emitted light in the visible range of the spectrum. Later scientists discovered that objects in space could also give out electromagnetic radiation from other, non-visible, parts of the spectrum, including microwaves, infrared, ultraviolet, gamma, X-rays and radio waves. Astrochemical research techniques use special radio telescopes to detect radio waves, which are given off by gases and stars. The information from these is combined with the findings from other instruments and telescopes, covering other areas of the spectrum, in order to build up a complete picture of the chemistry of space.
Advances in astrochemistry study have been made with the advent of telescopes that are not confined to Earth, as not all of the different wavelengths of electromagnetic radiation can travel through Earth's atmosphere. Visible light reaches Earth's surface, clouds permitting, as do radio waves, some microwaves and some infrared radiation. Ultraviolet and X-ray telescopes need to be positioned in space because ozone absorbs these types of radiation. Gamma rays may be detected by satellite-based instruments or, sometimes, by the changes they make when they interact with Earth's atmosphere.
Following astrochemistry research into the dust between stars, many different molecules have been recognized and the processes that led to their creation have been analyzed. Analysis of the astrochemistry of giant dust clouds in space and their comparison with molecular reactions on Earth enable scientists to understand how Earth's chemistry developed as it did. Research into the processes by which more complicated chemical structures are formed should give a greater understanding of the chemistry involved in the making of planets and stars. Astrochemistry researchers also study the creation of complex molecules that are rich in carbon, similar to terrestrial lifeforms, which could provide insights into how life on Earth began. If these complex molecules are able to originate in space, it would seem more likely that life exists in places other than Earth.