If you've ever seen a shooting star, you may have seen a meteor heading towards Earth. Meteorites are meteorites that fall to Earth and can be used to peek into the furthest reaches of space or the first building blocks of life. The biological components of the two meteorites have recently been the subject of the most extensive research. Tens of thousands of molecular "puzzle pieces" have been found, including more oxygen atoms than anticipated.
At the spring meeting of the American Chemical Society, the researchers will present their findings. (ACS). The mixed ACS Spring 26 meeting to be held from March 30-2023 will feature more than 10.000 speeches on various scientific topics.
Mass Spectrometry Technique
The group, led by Doctor Alan Marshall, had previously studied complex mixtures of organic compounds, such as petroleum, found on Earth. Now the sky, or rather the objects falling from the sky, is in the focus of their attention. They're starting to learn new things about the universe thanks to their ultra-high-resolution mass spectrometry (MS) technique, which could eventually open a window into the origins of life.
"This analysis gives us an idea of what's out there, what we're going to encounter as we move forward as a 'space-dwelling' species," said graduate student Joseph Frye-Jones, who will present the findings at the meeting. Marshall and Frye-Jones are employees of the National High Magnetic Field Laboratory and Florida State University.
Thousands of meteorites strike our planet each year, but only a small fraction of them is "carbonaceous chondrite," the type of space rock with the highest concentration of organic or carbon-containing matter. The "Murchison" meteorite, which crashed in Australia in 1969 and has been extensively investigated since then, is one of the best known. A more recent example is the as-yet undiscovered “Aguas Zarcas,” which exploded in Costa Rica in 2019, shattering kennels and even back patios as it fell to the ground. By analyzing the organic composition of these meteorites, researchers can learn where, when and what the rocks encountered on their journey through space.
Complex Molecules in Meteorites
Scientists used the MS method to make sense of the complex molecular entanglements in meteorites. This method effectively reports the mass of each particle seen as a peak after breaking a sample into small particles. The collection of spectra, or peaks, can be studied by scientists to reveal the contents of the first sample. But often, instead of providing information about unidentified components, the resolution of the spectrum is only sufficient to confirm the presence of a chemical that is presumed already present.
This is where “ultra-high resolution” MS, also known as Fourier-transform ion cyclotron resonance (FT-ICR) MS, comes into play. It has exceptionally high levels of resolution and accuracy and can evaluate extremely complex mixes. It is particularly useful for examining mixtures such as petroleum or complex organic matter from meteorites. According to Frye-Jones, “With this device, we have the resolution to look at everything in many different samples.”
Murchison and Aguas Zarcas Meteorites
To perform ultra-high resolution MS analysis, the researchers first extracted organic matter from samples of the Murchison and Aguas Zarcas meteorites. They looked at all soluble organic material at a time, rather than one specific type of molecule at a time, such as amino acids. In this way, the team analyzed more than 30.000 peaks for each meteorite, and more than 60% of them were assigned a specific molecular formula. According to Frye-Jones, these findings are the highest-resolution examination of the Murchison meteorite and the first such analysis of the Aguas Zarcas meteorite. In fact, compared to earlier reports for the older meteorite, their team found almost twice as many molecular formulas.
Once the data was generated, they were grouped into different groups based on various factors, including whether they contained oxygen or sulfur, whether they contained ring structure or double bonds, and other factors. The high oxygen level they discovered in the compounds caught them off guard. According to Marshall, you wouldn't consider oxygen-containing organic matter to be a major component of meteorites.
Scientists will then focus on two more invaluable examples: a few grams of lunar dust from the Apollo 1969 and 1971 missions in 12 and 14, respectively. These examples are older than the FT-ICR MS developed by Marshall in the early 1970s. Since then the instrumentation has improved considerably and is now ideally prepared for evaluating these powders. Scientists will soon compare data from Moon samples with results from meteorite analyzes to learn more about the origins of the Moon's surface. “Were meteorites used? Rays from the sun? We'll be able to clarify that soon,” says Marshall.
Source: eurekalert.org/news-releases/982716
Günceleme: 26/03/2023 17:42