Humans have looked to the stars since the dawn of our existence. If they were lucky, they’d catch a glimpse of a streak of light slicing through the night sky. Through archeological research, we know now that these early humans would actually find these mysterious, metallic sky stones, and know that they were not of this world. In hieroglyphs, “iron” literally translates to “metal of the sky.” We’ve found daggers, bracelets, and a headrest in Tutankhamun’s tomb that have been confirmed to be of meteoritic origin. Fragments of the Gibeon meteorite in Namibia were used by the Nama people for centuries; iron axes made of meteorites have been found in China, dated to around 1,400 BC; arrowheads in Switzerland, dated to 900 BC, have been found to be of meteoritic origin; among many other examples, from many other continents.
An estimated 48.5 tons (44 tonnes) of meteoritic material fall to Earth each day. Most are vaporized in the Earth’s harsh atmosphere, so precious few make it to the Earth’s surface. Fewer still survive conditions on our planet—they deteriorate via a process called weathering. Having floated for millions, even billions of years through the cold vacuum of space, sudden exposure to Earth’s conditions, especially after having survived a fiery descent through our cruel atmosphere, can be devastating.
The survivors are then left to sit, until a human being, whether by luck or by design, discovers them. Of these, some are sent to academic institutions for study. Their compositions are determined and they are classified; separated into groups according to their properties.
The study of meteorites is a relatively young science. Prior to the L’Aigle meteorite fall on April 26, 1803 in Normandy, France, the mere existence of meteorites was hotly contested. Jean-Baptiste Biot, a young scientist from the French Academy of Sciences, investigated the event and wrote a paper describing his findings. The evidence was undeniable; the stone fragments, all identical, had undoubtedly fallen from the sky. This was corroborated by many witnesses, who observed “a rain of stones thrown by the meteor.” This event, along with Biot’s paper, gave birth to the science of meteoritics.
That interest waned into the 1930s, and it was Harvey Harlow Nininger, a self-taught and self-funded meteoriticist from Kansas, that would revive scientific interest in meteorites. November 9, 1923 was the date credited with igniting Nininger’s passion for meteorites, and the unique labor of recovering them. Nininger taught biology and geology at McPherson College in Kansas at the time, and on that night, he and a fellow professor were walking home from a lecture when a fireball streaked the sky above them.
Nininger’s unique tenacity on the subject would result in his amassing the world’s largest collection of meteorites at that time. A meteorite hunter himself, Nininger was also accounting for half of all the meteorite discoveries back then, according to Fletcher Watson of Harvard University.
H. H. Nininger was also instrumental in the studying of Meteor Crater in Northern Arizona. Though he didn’t discover it, he did collect many iron meteorite specimens that he felt proved the enormous depression in the earth was due to a meteorite impact. Today, the 1.18-kilometer-wide and 170-meter-deep hole is renowned as the best-preserved crater on Earth. Nininger even moved his meteorite business from Denver to the Meteor Crater Observatory, which he renamed the American Meteorite Museum. From that location, Nininger published books on his findings at the crater, which included the discovery of impactites and iron-nickel spherules related to the vaporization of the mass upon impact.
Born in 1887, Nininger lived to see the Moon landing in 1969—naturally fascinated by the Moon, he wondered at its features, particularly a lunar tunnel near the Messier and W. H. Pickering pockmarks. “If rocket-borne explorers from the earth ever land on the Moon, they may be grateful for this tunnel,” he mused to in a “Time” magazine interview in 1952. Nininger passed away in 1986 at 99 years of age, shortly after the arrival of Haley’s Comet.
Though the old American Meteorite Museum building is a crumbling ruin, Nininger’s memory and influence live on. For one, his book, “Find a Falling Star,” has been recently re-released in an expanded version, titled “In Search of Falling Stars.” Published in 1972, the original manuscript was reduced by about 50% at the suggestion of the publisher, who felt it was too long. The long out-of-print book was expanded, compiled from multiple original manuscripts, handwritten notes, and correspondence.
“In Search of Falling Stars” is the new, unabridged version of H. H. Nininger’s beloved book, “Find a Falling Star.” Currently available for purchase from Aerolite Meteorites, this book tells a fascinating tale of a classic adventure scientist’s single-minded persistence. Add it to your shelf today!Click to purchase *SIGNED & NUMBERED*
Today, meteorites are of great relevance to the topic of the human settlement and development of space. First, the study of meteorites helps inform what we know about asteroids; these intriguing celestial bodies, scientists hope, may be rich with resources that can be mined and leveraged for our future in space. The materials we need to manufacture semiconducting electronics are becoming increasingly limited on Earth, but may be available on asteroids.
Asteroids also have the potential to contain water ice that can be processed into fuel or used for life support, or materials that can be used to build spacecraft or other tools. Unlike meteorites, asteroids have not been mired by terrestrial conditions and remain untouched fragments of our early solar system, providing us much to study. Asteroids potentially contain scientifically valuable low-density material that would burn up in Earth’s atmosphere.
To that end, asteroid return sample missions have become a new focus for scientists seeking to better understand our solar system and how it formed. The OSIRIS-REx asteroid-study and sample-return mission launched in 2016 and rendezvoused with Bennu in 2018. Viewed as a “time capsule” from the birth of the solar system, Bennu is a primitive asteroid and has changed little since the time it was formed. Bennu also contains carbonaceous material, which is one of life’s key ingredients. The aim of the mission, then, was to study material from Bennu to better understand the formation and evolution of the solar system and the source of organic compounds that led to life on Earth.
The OSIRIS-REx mission was extended in 2022 and became OSIRIS-APEX (Apophis Explorer). The new target, near-Earth asteroid Apophis, will make a close pass to Earth in 2029. At that point, the spacecraft will attempt to rendezvous with the asteroid and collect a sample, in similar fashion to the sample collected from Bennu.
What scientists discovered about the composition of Bennu, after studying the return sample, was unprecedented. Pristine magnesium-sodium phosphates found in the Bennu sample suggests that the asteroid could have originated from a primitive ocean world. The team also found that Bennu is rich in nitrogen and carbon, which are vital for life as we know it.
Other notable sample return missions include the 2010 Japan Aerospace Exploration Agency (JAXA) Hayabusa probe, which returned micrograms of dust from the S-type asteroid Itokawa. Later, in 2018, the Hyabusa2 probe returned samples of the C-type asteroid Ryugu, which was found to contain thousands of different amino acids, aromatic hydrocarbons, and other carbon-based molecules. This discovery further supports the idea that organic material from space could have jump-started life here on Earth.
Sample-return missions circumvent the need to wait for meteorites to fall on Earth so we can study them; however, they are costly, of time and money. Meteorites can answer many of our most prescient questions in the interim. Nininger, recognizing the need to support interest in studying meteorites, endowed the Nininger Science of Meteortics fund to the Center for Meteorites Studies at Arizona State University. He and his wife, Addie, wanted to promote interest in meteorites and related topics among up-and-coming students.
The fund supports the Nininger Meteorite Award, which recognizes outstanding student achievement in meteorite studies. Dr. Dante Lauretta, the Principle of Investigator of the OSIRIS-REx mission, won the award in 2002.
Most recently, the award was given to a team of students for their research paper examining what can be learned of magnetism from aubrite meteorites. The paper describes the magnetic fields that permeate the universe, allowing rocky planets to collect a shield of charged particles around themselves, which in turn acts as a protective barrier against solar radiation.
The paper examines aubrites and assesses them as analogues for Mercury; as of yet, there are no known samples from the closest planet to the sun. Aubrites, sometimes called enstatite meteorites for their nearly monomineralic nature, provide a valuable opportunity to study highly reduced systems in our solar system, like Mercury. Understanding these environments is valuable to human efforts to better understand, and eventually settle, space.
