Meteorites & Asteroids Archives

High enantiomeric excesses (ee’s) of l-amino acids, including non-proteinogenic amino acid isovaline (Iva), were discovered in the Murchison meteorite, but the detailed molecular mechanism responsible for the observed ee of amino acids remains elusive and inconsistent, because Iva has an inverted circular dichroism (CD) spectrum with respect to α-H amino acids, e.g., alanine. To address this issue, we resort to accurate ab initio calculations for amino acids and their precursors in the Strecker synthesis. We evaluated their photolysis-induced ee in the range 5–11 eV including the Lyman alpha emission line (Lyα), the typical intensive 10.2 eV radiation ascribed to the early phase of galactic evolution. We show that only the aminonitrile precursors are characterized by positive ee in the Lyα region, explaining why right-handed circularly polarized Lyα (R-CP-Lyα) induces homologous l-amino acids. This study shows that the homochirality of amino acids is produced at the aminonitrile precursors stage.-- The Journal of Physical Chemistry Letters

Astrochemistry, Biochemistry & Organic Chemistry, Meteorites & Asteroids, Press Release

New Study Provides Novel Insights Into The Cosmic Evolution Of Amino Acids

by Keith CowingMay 26, 2023

All biological amino acids on Earth appear exclusively in their left-handed form, but the reason underlying this observation is elusive.

A small fragment of the Campo del Cielo iron meteorite. The same intense heat that partially melted the meteorite to produce the smooth surface visible here would have also evaporated and ablated iron, creating tiny, nanometer-sized particles. These particles could have acted as catalysts for producing the building blocks of life on the early Earth. © O. Trapp

Astrochemistry, Astrogeology, Meteorites & Asteroids, Origin & Evolution of Life, Press Release

A Role For Meteoritic Iron In The Emergence Of Life On Earth

by Keith CowingMay 25, 2023May 25, 2023

To the best of our current knowledge, life on Earth emerged a mere 400 to 700 million years after the Earth itself had formed.

Apollo 17 sample being handled by NASA curators in a a nitrogen-purged cold glovebox using gloves and protective gear. -- NASA/Robert Markowitz.

Meteorites & Asteroids, Missions & Hardware, Planetary Protection & Biosafety, Press Release

NASA Support for Planetary Sample Science (SPSS) Cooperative Agreement Notice (CAN) and Questions and Answers (Q&A) Released

by Keith CowingMay 11, 2023May 11, 2023

CAN/Q&A Release Date: May 11, 2023Number: NNH23ZDA017CStep-1 Proposals Due: June 12, 2023Step-2 Proposals Due: July 24, 2023Number: NNH23ZDA017C

A lightning strike in New Port Richey, Florida, led to a chemical reaction creating a new material, pictured here, that is transitional between space minerals and minerals found on Earth. CREDIT Matthew Pasek/University of South Florida

Astrochemistry, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biophysics, Meteorites & Asteroids, Origin & Evolution of Life, Press Release

Lightning Strike Creates Phosphorus Material For The First Time On Earth

by Keith CowingApril 11, 2023April 11, 2023

After lightning struck a tree in a New Port Richey neighborhood, a University of South Florida professor discovered the strike led to the formation of a new phosphorus material. It […]

Fusion-crusted individual piece of Aguas Zarcas. Top right of stone shows dirt from its impact with the Earth. Photo: ASU/CMS/L. Garvie.

Astrochemistry, Astrogeology, Biosignatures & Paleobiology, Comets and Asteroids, Meteorites & Asteroids, Press Release

Two Meteorites Are Providing A Detailed Look Into Astrochemistry

by Keith CowingMarch 27, 2023March 27, 2023

If you’ve ever seen a shooting star, you might have actually seen a meteor on its way to Earth. Those that land here are called meteorites and can be used […]

While not part of this study, this photo taken with a microscope shows the impact paths and bodies of small particles of comet debris from U.S. space agency NASA’s Stardust mission in 2004. The aerogel helps decelerate the particles without destroying them in the process. CREDIT ©2023 NASA/JPL CC-0

Astrochemistry, Astrogeology, Impact events, Interstellar, Meteorites & Asteroids, Panspermia, Press Release

Searching For Life With Space Dust

by Keith CowingMarch 22, 2023March 22, 2023

Following enormous collisions, such as asteroid impacts, some amount of material from an impacted world may be ejected into space.

Astrochemistry, Biochemistry & Organic Chemistry, Genomics, Proteomics, Bioinformatics, Meteorites & Asteroids, Missions & Hardware, Press Release

Uracil Has Been Found In Asteroid Ryugu Samples

by Keith CowingMarch 21, 2023March 21, 2023

Researchers have analyzed samples of asteroid Ryugu collected by the Japanese Space Agency’s Hayabusa2 spacecraft and found uracil—one of the informational units that make up RNA, the molecules that contain […]

Earth's water did not come from melted meteorites

Astrochemistry, Biogeochemical Cycles & Geobiology, Icy Worlds, Meteorites & Asteroids, Press Release, Water/Hycean Worlds & Oceanography

Where Did Earth’s Water Come From? Not Melted Meteorites

by Keith CowingMarch 15, 2023March 15, 2023

Water makes up 71 percent of Earth’s surface, but no one knows how or when such massive quantities of it arrived on Earth.

Cartoon illustrating our preferred scenario

Astrochemistry, Astrogeology, Comets and Asteroids, Meteorites & Asteroids, Status Report

Origin Of Isotopic Diversity Among Carbonaceous Chondrites

by Keith CowingMarch 8, 2023March 8, 2023

Carbonaceous chondrites are some of the most primitive meteorites and derive from planetesimals that formed a few million years after the beginning of the solar system.

Astrochemistry, Astrogeology, Meteorites & Asteroids, Status Report

Representation Of S-process Abundances For Comparison To Data From Bulk Meteorites

by Keith CowingMarch 3, 2023March 3, 2023

Analysis of bulk meteorite compositions has revealed small isotopic variations due to the presence of material (e.g., stardust) that preserved the signature of nuclear reactions occurring in specific stellar sites. […]