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

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

How Visual Cortex inspired the Convolutional Neural Networks

By -
Image
Introduction Since the 1960s, after the successful development (at least with respect to the existing technologies of that time) of the first perceptron by Frank Rosenblatt, researchers around the world have been trying to make computers more brain-like. In other words, they are constantly trying to develop programs and hardware that work much like our brains. However, creating a machine that thinks and programs like a human brain is still impossible, given the limitations of present technologies. But, we are successful in this direction up to an agreeable extent. The perceptron developed by Rosenblatt can be considered one of the first implementations of neural networks. It was a huge hardware model, rather than a Python program like today's perceptrons.  Rosenblatt's perceptron was a simple binary input-output system, with various limitations. It was not trainable for different patterns, rather but for simple image recognization. The major drawback was its inability to perfor
Read more

Exoplanets' Structures

By -
Image
Exoplanets' structures In the coming decade, observational campaigns will help us further our understanding of planet structure, both within and outside of our solar system. The long-standing question of how much water there is in Jupiter should be answered thanks to the Juno mission, which will offer critical new insights into Jupiter's interior structure. The recently authorized Transiting Exoplanet Survey Satellite will locate several planets outside of our solar system that is located around stars that are close enough and bright enough to allow for follow-up studies from the ground or using the James Webb Space Telescope. Our knowledge of these planets' bulk compositions and architectures will be influenced by what we learn about their masses (through radial velocity measurements) and atmospheres. Finally, in some circumstances, large exoplanets, like those in the HR 8799 system, that are sufficiently remote from their stars and sufficiently self-luminous, may be dir
Read more

Confronting Biodiversity Challenges in Marine Video Monitoring

By -
Image
Introduction Our current generation is facing the challenges of climate change and global warming. The series of feedback events due to the constant degradation of the environment resulted in anthropogenic defaunation and declination in the quality of the entire ecosystem. For centuries, humans have been keeping a watch on species using various methods like drawings, writings and paintings. Then photographs and videos were introduced to study and track various species. The introduction of video tracking played an impactful role in studying marine biodiversity. Oceans cover 71% of the Earth, which is around 361 million sq km. Monitoring marine species has been a challenge for researchers for decades. Ocean provides a home to a wide range of species, some are even yet to be discovered. Video surveys are making things easy for the researchers. They have the capability to monitor underwater activities with much greater accuracy and precision. These surveys can search for species and monito
Read more