esearchers have analyzed carbon-rich meteorites (carbonaceous chondrites) and found amino acids, which are used to make proteins. Proteins are among the most important molecules in life, used to make structures like hair and skin, and to speed up or regulate chemical reactions. They have also found components used to make DNA, the molecule that carries the instructions for how to build and regulate a living organism, as well as other biologically important molecules like nitrogen heterocycles, sugar-related organic compounds, and compounds found in modern metabolism.
This photo compares the sample size typically used in meteorite studies (yellow oval) to the sample size used with the new equipment (blue circle) in Goddard's Astrobiology Analytical Laboratory. Image Credit: Michael Callahan
This equipment is used by Goddard's Astrobiology Analytical Lab to analyze very small samples. On the right is the nanoelectrospray emitter, which gives sample molecules an electric charge and transfers them to the inlet of the mass spectrometer (left), which identifies the molecules by their mass. Image Credit: Michael Callahan
However, these carbon-rich meteorites are relatively rare, comprising less than five percent of recovered meteorites, and meteorites make up just a portion of the extraterrestrial material that comes to Earth. Also, the building-block molecules found in them usually have been at low concentrations, typically parts-per-million or parts-per-billion. This raises the question of how significant their supply of raw material was. However, Earth constantly receives other extraterrestrial material – mostly in the form of dust from comets and asteroids.
"Despite their small size, these interplanetary dust particles may have provided higher quantities and a steadier supply of extraterrestrial organic material to early Earth," said Michael Callahan of NASA's Goddard Space Flight Center in Greenbelt, Md. "Unfortunately, there have been limited studies examining their organic composition, especially with regards to biologically relevant molecules that may have been important for the origin of life, due to the miniscule size of these samples."
Callahan and his team at Goddard's Astrobiology Analytical Laboratory have recently applied advanced technology to inspect extremely small meteorite samples for the components of life. "We found amino acids in a 360 microgram sample of the Murchison meteorite," said Callahan. "This sample size is 1,000 times smaller than the typical sample size used." A microgram is one-millionth of a gram; 360 micrograms is about the weight of a few eyebrow hairs. 28.35 grams equal an ounce.
"Our study was for proof-of-concept," adds Callahan. "Murchison is a well-studied meteorite. We got the same results looking at a very small fragment as we did a much larger fragment from the same meteorite. These techniques will allow us to investigate other small-scale extraterrestrial materials such as micrometeorites, interplanetary dust particles, and cometary particles in future studies." Callahan is lead author of a paper on this research available online in the Journal of Chromatography A.
Analyzing such tiny samples is extremely challenging. "Extracting much less meteorite powder translates into having much lower amino acid concentration for analyses," said Callahan. "Therefore we need the most sensitive techniques available. Also, since meteorite samples can be highly complex, techniques that are highly specific for these compounds are necessary too."
The team used a nanoflow liquid chromatography instrument to sort the molecules in the meteorite sample, then applied nanoelectrospray ionization to give the molecules an electric charge and deliver them to a high-resolution mass spectrometer instrument, which identified the molecules based on their mass. "We are pioneering the application of these techniques for the study of meteoritic organics," said Callahan. "These techniques can be highly finicky, so just getting results was the first challenge."
"I'm particularly interested in analyzing cometary particles from the Stardust mission," adds Callahan. "It's one of the reasons why I came to NASA. When I first saw a photo of the aerogel used to capture particles for the Stardust mission, I was hooked."
"This technology will also be extremely useful to search for amino acids and other potential chemical biosignatures in samples returned from Mars and eventually plume materials from the outer planet icy moons Enceladus and Europa," said Daniel Glavin of the Astrobiology lab at Goddard, a co-author on the paper.
This technology and the laboratory techniques that the Goddard lab develops to apply it to analyze meteorites will be valuable for future sample-return missions since the amount of sample likely will be limited. "Missions involving the collection of extraterrestrial material for sample return to Earth usually collect only a very small amount and the samples themselves can be extremely small as well," said Callahan. "The traditional techniques used to study these materials usually involve inorganic or elemental composition. Targeting biologically relevant molecules in these samples is not routine yet. We are not there either, but we are getting there."
The research was funded by the NASA Astrobiology Institute, the Goddard Center for Astrobiology and the NASA Cosmochemistry Program.Bill Steigerwald
Bill Steigerwald | EurekAlert!
APEX takes a glimpse into the heart of darkness
25.05.2018 | Max-Planck-Institut für Radioastronomie
First chip-scale broadband optical system that can sense molecules in the mid-IR
24.05.2018 | Columbia University School of Engineering and Applied Science
The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.
Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...
A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.
The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
25.05.2018 | Event News
02.05.2018 | Event News
13.04.2018 | Event News
25.05.2018 | Event News
25.05.2018 | Machine Engineering
25.05.2018 | Life Sciences