Rare meteorite provides snapshot of early solar system

A rare CM½ carbonaceous chondrite meteorite that crashed into a New Jersey home has revealed a diverse suite of extraterrestrial amino acids and evidence of ancient icy brines. According to a study published in Science Advances, the specimen provides a unique window into the subsurface of the original asteroid and the delivery of organic molecules to early Earth.

Hillsborough Meteorite: A Rare Glimpse into Early Solar System Water

The space rock, weighing over two pounds (1 kilogram), struck a master bedroom in Hillsborough, New Jersey, after a fireball was spotted across the Northeast on July 16, 2024. Peter Jenniskens, a senior research scientist at the SETI Institute and NASA’s Ames Research Center, identified the object as a primitive CM-type carbonaceous chondrite.

Researchers classified the sample as a CM½ because its composition sits between the two primary types of primitive CM meteorites, CM1 and CM2. The difference between these types depends on how much water altered the rock while it was part of a larger asteroid. Jenniskens noted this is only the second time a CM½ meteorite has been witnessed falling to Earth, and the first time scientists have studied such a pristine sample.

Extraterrestrial Amino Acids and the Origin of Life

The analysis uncovered a complex suite of amino acids—the building blocks of proteins—within water extracts of the meteorite. Dr. Danny Glavin, a senior scientist for the Sample Return in the Solar System Exploration Division at NASA’s Goddard Space Flight Center, stated that most of these amino acids are rare or nonexistent in life on Earth, confirming their extraterrestrial origin.

Glavin noted that the diversity of amino acids in the Hillsborough sample exceeds those found in pristine samples returned from the carbon-rich asteroids Bennu and Ryugu. This suggests that carbonaceous chondrites may have played a critical role in delivering the organic matter necessary for the origin of life on Earth.

Comparison of Asteroid Sample Sources

The Role of Icy Brines and Asteroid Evolution

The research team detected high levels of sodium, which they attribute to icy brines within the parent asteroid. As water evaporated, it left behind concentrated salt minerals. Peter Brown, a professor in the department of physics and astronomy at Western University in London, Ontario, described these as leftovers of “percolating water or ice.”

According to Jenniskens, the meteorite likely originated from a large collision in the inner asteroid belt between Mars and Jupiter. A smaller collision roughly 6 million years ago broke off a piece that eventually entered near-Earth orbit. That fragment broke further about 200,000 years ago before finally hitting Earth.

Preservation and Scientific Recovery

The scientific value of the Hillsborough meteorite was preserved by the homeowners’ immediate actions. Following guidance from Mike Hankey of the American Meteor Society, the owners used disposable gloves, aluminum foil, and glass jars to collect the fragments.

Jenniskens emphasized that patching the roof before rain fell that evening was crucial. Because the meteorite is porous and absorbs water from the air, rainfall would have contaminated the sample or caused it to disintegrate. Fragments are now curated at the American Museum of Natural History in New York City.

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