Composition of Murchison meteorite

By -

Composition of Murchison meteorite

Introduction:

During the early days of the formation of the Earth, carbon-rich meteorites played a significant role in delivering organic molecules. Apart from enriching the crust of Earth with organic molecules, these meteorites also played a critical role in developing and evolving our home planet's atmosphere. Of the uncountable meteorites that fell on Earth, here we will discuss a particular one, the Murchison meteorite, in-depth.

Overview of Murchison:

In 1969, a meteorite with more than 100 kg of mass fell on the Australian village of Murchison. It was named Murchison (derived from its impact site). The meteorite was full of organic molecules and today it is one of the most studied meteorites of all the meteorites. The Murchison meteorite is older than the Earth and even the Solar System. More than 15 amino acids have been discovered from the Murchison till today. Silicon Carbide, the oldest material found on Earth was also detected in the Murchison meteorite. Advance studies proposed that the Murchison is full of carboxylic acids, hydrocarboxylic acids and fullerenes.

Chemistry of Murchison:

The diversity of organic compounds discovered on the Murchison helped researchers to understand the chemistry of early interstellar objects that existed before or at the time of the birth of the Solar System. More than 70% of the carbon content of the Murchison has been classified as (macromolecular) insoluble organic matter (IOM) of high aromaticity. This IOM is actually a major component of almost all interstellar objects. The high aromaticity can be directly linked to the high stability of these molecules.  

 
Composition of Murchison meteorite
Example of IOM found from Murchison

The samples of IOM from Murchison were studied by both, destructive and non-destructive methods. The destructive method includes chemical and thermal degradations followed by the GC/MS (gas chromatography/ mass spectrometry). Non- destructive methods mainly include various spectroscopic techniques like Fourier Transform Infrared Spectroscopy [FTIS], X- Ray Absorption Near Edge Spectroscopy [XANES] and Nuclear Magnetic Resonance [NMR].

Now let's understand this in easy language. Thermal degradation means the breaking of a molecule (or molecular chains) using heat. Similarly, chemical degradation uses chemical reactions to degrade or break the molecule. Gas chromatography is a technique used to separate and analyze the compounds that can be vaporized. Mass spectrometry is another analytical technique used to measure the mass to charge ratio of ions. In GC/MS, the applications of both techniques are combined for a more detailed analysis of the compound. 

FTIR as the name suggest is used to obtain the infrared spectrum of compounds. The implementation of this technique is a bit similar to the GC/MS. However, FTIR is now widely used due to its less sensitivity than the GC/MS. NMR is used to measure the magnetic field of the atomic nuclei of various compounds. The aromatic nature of the IOM compounds found from the Murchison was detected by the FTIR technique. 

Another technique that helped researchers to study the chemistry of Murchison was High-Resolution Transmission Electron Microscopy (HRTEM). HRTEM is a very efficient technique for the direct imaging of the atomic structure of any compound. Carbon-carbon bonding (especially sp² bonding). 

Further analysis of the meteorite samples using GC/MS resulted in the detection of xanthine, adenine, hypoxanthine, uracil and guanine. Xanthine is mainly found in human tissues and many plant cells. Guanine and Adenine are the building blocks of DNA. Uracil is a building block of RNA. The detection of these compounds revealed that the origin of life on Earth is highly impacted by the influence of extraterrestrial objects that fell on Earth. We can say that it is due to these meteorites that today we advanced and complex chemistry on Earth. The synthesis of protein on Earth is also believed to start after the impact of such meteorites. 

Composition of Murchison meteorite
Murchison meteorite at the The National Museum of Natural History (Washington)
Source : Wikimedia 

One can say that the meteorites like Murchison are the reason for the origin of organic compounds (and eventually life) on Earth. Apart from these compounds, various amino acids, nucleobases and different forms of sugar are also identified as major components of Murchison. It is important to note that xanthine and uracil are capable of self-association in monolayer structure. Continuous addition of meteoritic uracil and xanthine and some other nucleobases on land might have influenced prebiotic organic reactions necessary for the origin of life on Earth. One can say that the meteorites like Murchison are the reason for the origin of organic compounds (and eventually life) on Earth. Apart from these compounds, various amino acids, nucleobases and different forms of sugar are also identified as major components of Murchison.   

Comments

Post a Comment

Please do not use foul language while commenting. We will appreciate your suggestions and reviews in the comments.

Read Also

Deep Neural Networks for ADMET properties' prediction

By -
Image
Introduction The absorption, distribution, metabolism, excretion and toxicity properties of any compound contributes to its potential as an orally administered drug. A set of criteria defined by Rule of Five or the Pfizer's Rule of Five stats that any compound meeting these criteria are more likely to have ADMET properties. The importance of these properties has increased in modern medicinal chemistry and new machine learning techniques are employed to predict these properties. The predictive ADMET models have helped in discovery of small molecules with improved safety and dose. Deep Neural Networks are showing usefulness in such predictions due to improved computational efficiency, larger datasets and adaption of image processing in the chemistry. Early Models The early DNNs employed showed improved prediction performance. Many researchers raised concerned that this improvement is in fact has no relation with better computational capacity, rather it is result of mere memorizing of
Read more

Marine eDNA Analysis using DL techniques

By -
Image
Introduction Environmental DNA (eDNA) is the genetic information or material released by an organism into its surroundings through activities like skin shedding, mucus, urine or other secretions. These materials contain DNA fragments that can be found in soil, water or air samples. The concept of eDNA is based on the fact that organisms constantly leave organic traces behind them. By analysing the eDNA, researchers can detect the presence of any species in that area. This method is a valuable technique for biodiversity monitoring and ecological research.    Unlike traditional methods that involve direct observation or capturing of organisms, eDNA analysis allows researchers to study biodiversity without directly interacting with the species. This non-invasive approach is particularly useful for studying elusive or endangered species. eDNA analysis has been applied in various ecosystems, including freshwater, marine, and terrestrial environments. It is used to study aquatic organisms, t
Read more

Assisting Neuroimaging through DL

By -
Image
Introduction: In recent years, neuroimaging has been a research attraction, especially due to fMRI (Functional Magnetic Resonance Imaging) advancements. The fMRI data comprises of often several individuals. This data is used by researchers to study the association between the cognitive states of an individual and the underlying brain activities. The fMRI data used for neuroimaging is ideally suited for deep learning applications. The large, structured datasets of fMRI can be used for representation-learning methods of the DL. Generally, DL can be defined as a learning method with multiple levels of abstraction, where at each level the input data is transformed by a simple non-linear function which enables the model to recognize complex patterns. With higher-level representation, DL methods can associate a target variable with variable patterns in input data. Also, DL techniques can independently acquire these transformations from the data, eliminating the need for a comprehensive preex
Read more

What is Terraforming?

By -
Image
  Humans are working more and more on extraterrestrial habitations. A few decades back we were planning to settle on the Moon and now we are planning the same on Mars. Many researchers also proposed many theories on such habitations as O'Neill Cylinder, McKendree Cylinder, and many more. One such famous hypothetical theory is Terraforming. But what does the term terraforming mean? Terraforming is the process of transforming the atmosphere, topography, temperature and other factors of any moon or planet to make it habitable and similar to the Earth. It was Carl Sagan who first proposed the theory of terraforming. He proposed the terraforming of Venus. He thought of seeding Venus with algae. The algae will convert nitrogen and carbon dioxide to organic matter and eventually, the greenhouse effect will reduce to a comfortable, habitual level.  However, later studies revealed that the clouds of Venus are full of sulphuric acid. Also, the atmosphere of Venus is very thick, any carbon co
Read more