Abstract
Carbon and its compounds have been already observed in the early Universe. It is very important to figure out the prebiotic reservoirs that exist on the earth. During cosmic times, many galaxies have undergone star formation and thanks to this many heavy elements like carbon, oxygen, nitrogen, silicon and iron additionally as some complex molecules like carbon monoxide gas and polycyclic aromatic hydrocarbons are detected within the system. During the extreme bombardment of the phase, many large amounts of extraterrestrial materials were transported to young planetary surfaces via asteroids, comets. We also comment that they guide us to expand our knowledge to other habitable worlds.
Introduction
The study of evolution of organic matter describes a cosmic question for a stronger understanding of the chemical origins, starting with the large bang theory up to interstellar clouds, the solar nebula, the formation of the sun and planets, the origin of life on earth. There are a range of sources for prebiotic organic molecules, including those from the earth’s atmosphere, in hydrothermal vents within the Earth’s ocean and a variety of extra-terrestrial sources.
Image 1 - Inter-relationships between various bodies in the chemical evolution of the solar system.
Prebiotic organic molecules don't seem to be produced by living things and so do not have any biological origin.
Image 2 - Helix Nebula.
Complexity of Organic Matter in Space
Some of the researchers reported that the complexity of organic compounds exists throughout the universe in which organic compounds are the mixture of aromatic and aliphatic components.The compounds are so complex that they need resemblance to those of coal and oil.the complex organic compounds might be synthesized in space when no living things are present. Stars called Novae, shows that stars produce complex organic compounds on a brief continuance like weeks, which stars not only produce these complex organic compounds, but also expel them into the part,between the stars.
Image 3 - Star Dust
Interstellar Clouds
An Interstellar Cloud is a combination of gas, plasma, dust within the galaxies. it's a denser region where matter and radiation exists within the space between the star systems in an exceedingly large galaxy. Interstellar clouds, also called dark nebulae, interstellar clusters, are made of grains of dust. Interstellar gas and mud clouds frame to 50% of galactic matter and also accommodate Hydrogen (H) and Helium (He).
There are two kinds of Interstellar clouds:-
Dark and dense clouds:- they're rich in dust, molecular hydrogen is the dominant species and also the gas concentration varies from 103 to 107 molecules/cm3.
Very diffuse clouds:- Contains atiny low amount of dust, the concentration of hydrogen may be a dominant species, and also the gas concentration is incredibly low.
Image 4 - Interstellar Clouds
Many of the organic compounds are observed and sampled in our solar system, including interplanetary dust, comets, asteroids, planetary surfaces. Asteroid 2008 TC3 recently revealed interesting insights into the chemistry of asteroids.
Image 5 - Asteroid 2008 TC3
Meteorites: Key Building Block of Organic Molecules
The researchers discovered a prebiotic molecule, hexamethylenetetramine (HMT), in three different carbon rich meteorites. It confirms that HMT could even be a crucial molecule within the formation of organic compounds in an interstellar environment.
The two parent bodies of the many meteorites, formaldehyde and ammonia, are accustomed to explain the formation of meteoritic molecules like amino acids and sugars. The HMT on meteorites confirms that ammonia and formaldehyde are stable sources on asteroids. HMT breaks down into building blocks, formaldehyde and ammonia, which successively produce other biological molecules including amino acids, proteins, etc. These biological molecules are wont to build structures like hair and nails and it also accelerates or regulates the chemical reactions.
The most important meteorites for the research area are carbonaceous chondrites, stony meteorites that contain high proportions of water and organic compounds. Experiments have proven that the aggregation of water, ammonia and methanol while subjected to photochemical and thermal conditions in an extra-terrestrial environment, offers rise to several natural compounds along with the most common natural compound, HMT.
Image 6 - Murchison meteorite
The scientists evolved a way that mainly extracted HMT from meteorites with minimum breakdown which allowed them to isolate massive portions of HMT and HMT derivatives from the meteorites:- Murchison, Murray and Tagish Lake.
Image 7 - Daniel Glavin powdering the Murchison
meteorite in a HEPA filtered laminar flow bench
Where did Organic Compounds come from?
The first organic compounds have been fashioned from the carbon injected into the interstellar medium beneath the effect of cosmic rays and Ultraviolet light. Hydrocarbons together with Hydrogen (H), Oxygen (O2), Sulphur (S) and many other compounds are fashioned on this cloud of dust and molecules.
Carbon in Universe
All the carbon within the universe is created of fusion reactions present within the stars. Carbon-13 (13C) is made late within the lives of red giant stars, where the formation of the Helium catalyzed by 12C ends up in the formation of 13C, 14N and 15O via the CNO cycle.
Image 8- Outline of the CNO cycle
Conclusion
The cycle of beginning and demise of stars continuously will increase the abundance of heavy elements within the interstellar space. Observations of the oldest stars suggests that Carbon has been shaped already within the very early universe. The extra-terrestrial contribution arrived via comets, asteroids and tiny fragments during the LHB phase 3.9 Gyr (billion years) ago.How heavy elements gather to make complex molecules and evolve in interstellar regions and the way they're incorporated into forming planetary systems to make life are investigated under the interdisciplinary umbrella of astrobiology.