Astrobiology is one of the branches of Astronomy, which aim is exploring the origin and spread of life on space objects besides Earth. Astrobiology is an interdisciplinary field combining chemistry, biology, physics, geography and astronautics.
One of the main sticking points in Astrobiology is the definition of life. Because of this issue, astrobiology is divided into two main areas - classical astrobiology and xenobiology. Astrobiology is engaged in the search for living organisms that are similar in chemical compound to the love organisms of the Earth (hydrocarbon composition, the presence of DNA). Xenobiology suggests that the existence of life forms based on a different chemical compounds is more likely, for example, on silicon, phosphorus, and nitrogen.
One of the main objectives of astrobiologists is the search for life or traces of life on the planets of the Solar System.
Despite the fact that the temperature difference makes the existence of complex organic life on other planets almost impossible, bacteria on Mars have already been discovered, and also the existence of traces of life on satellites of Jupiter and Saturn is possible. It is assumed that living things can also exist on Venus.
In addition, astrobiology is developing a hypothesis that life on Earth could have been brought from outer space. Traces of microorganisms were found on comets and meteorites, which supports this theory.
Students can choose Astrobiology specialization while studying Astronomy in university. Nowadays, more than twenty universities in USA hold study programs with specialization in Astrobiology.