NASA Study of Pristine Meteorite That Crashed Through a New Jersey Roof Reveals Ancient Asteroid Brines and Life’s Building Blocks
Featured image: NASA/JSC image of a polished slice of the Hillsborough meteorite showing C1 clasts embedded in the CM2 matrix; credit: NASA/JSC
A meteorite that crashed through a New Jersey homeowner’s roof in July 2024 has turned out to be one of the most scientifically valuable space rocks ever recovered, preserving evidence of ancient brines that flowed through asteroids more than 4.5 billion years ago alongside a complex cocktail of organic molecules that may have seeded life on Earth.
A 31-author NASA study published July 15 in Science Advances reveals that the Hillsborough meteorite contains microscopic fractures filled with sodium-rich material left behind by ancient, salt-laden brines on the parent asteroid. It is the first time brine-related sodium-carbonate salts have ever been identified in a CM-type carbonaceous chondrite, bridging the gap between samples returned from asteroids Bennu and Ryugu and the meteorites that fall to Earth.
“Together, those complementary studies are helping scientists build one of the clearest pictures yet of how primitive asteroids such as the asteroid Erigone evolved chemically over billions of years,” said lead author Peter Jenniskens of NASA Ames and the SETI Institute.
A Fortuitous Fall and Rapid Recovery
On July 16, 2024, a daytime fireball lit up the sky over the New York metropolitan area. Fragments of the asteroid slammed into Hillsborough, New Jersey, with one piece punching through a residential roof. Crucially, the homeowner was an amateur astronomer who immediately recognized the fallen rock, wore protective gloves to handle it, and stored the fragments in aluminum foil and glass jars. That rapid recovery preserved delicate minerals and organic compounds that would have degraded within hours of exposure to Earth’s air.
“Thanks to the homeowner’s quick reaction, these are the most pristine CM1/2 meteorites we know of,” Jenniskens said.
The meteorite, classified as a CM1/2 carbonaceous chondrite, weighed about 1.35 kilograms total. It is only the second observed fall of this rare alteration type in history. Its trajectory was traced back to the inner asteroid belt, possibly to the Erigone asteroid family: home to asteroid Donaldjohanson, which NASA’s Lucy mission visited in 2025.
What the Meteorite Reveals
The NASA team found that the Hillsborough meteorite is a breccia (a rock made of fragments of other rocks) containing 95 to 98 percent CM2 clasts (moderately altered) alongside rare CM1 clasts (completely water-altered). It is these CM1 clasts that contain the scientific treasure.
Sodium-rich brines: The CM1 clasts contain more than 5 percent sodium oxide by weight, compared to just 0.09 to 0.36 percent in normal CM chondrites. The sodium is concentrated in fractures within dolomite crystals, interpreted as evidence of late-stage, salt-rich brines flowing through the parent asteroid at temperatures below -15 degrees Celsius.
“This is the first evidence we have of these kinds of brines in CM-type asteroids,” the team reported. The salts closely resemble those found in samples from asteroids Bennu (returned by NASA’s OSIRIS-REx mission) and Ryugu (returned by JAXA’s Hayabusa2 mission), showing that brine-driven chemical alteration was not unique to one asteroid class but was widespread across the early solar system.
“The chips of the most salt-rich bits of this meteorite are quite comparable to the samples returned by the Hayabusa2 and OSIRIS-REx missions,” said co-author Mike Zolensky of NASA Johnson Space Center. “They’re not identical. They’re different in some very interesting ways, but they’ve seen very similar processes.”
Complex organic chemistry: The Hillsborough meteorite also contains a rich array of amino acids (ranging from C2 to C11 chains), carboxylic acids, and organometallic compounds comparable to the legendary Murchison meteorite. The complex distribution of amino acids likely formed within the parent asteroid, assisted by the brine chemistry.
“One of the big surprises for me when we analyzed a small chip of the Hillsborough meteorite was the complexity of amino acids and other organic compounds,” said co-author Danny Glavin of NASA Goddard’s Astrobiology Analytical Lab. “It’s just more proof that the chemical building blocks of life could have been delivered, and are still being delivered, to Earth today by these carbonaceous asteroid fragments.”
A Window Into the Early Solar System
The Hillsborough meteorite offers a uniquely pristine Earth-based comparison sample for the Bennu and Ryugu materials, helping planetary scientists understand the full range of chemical environments on primitive asteroids. The presence of sub-zero brines suggests that liquid water existed and flowed beneath the surfaces of asteroids across the inner solar system, transporting elements and producing the chemical precursors of life.
“If you follow the water through the solar system, you’re actually following life,” Zolensky said. “Following the history of water through the solar system is an essential part of understanding the origin of life.”
The study, published open access in Science Advances (Vol. 12, Issue 29), represents a multidisciplinary effort involving NASA Ames, Johnson Space Center, Goddard Space Flight Center, the SETI Institute, ETH Zurich, Stanford University, and international partners. It combines fireball trajectory reconstruction, radar data, electron microscopy, isotope geochemistry, noble gas analysis, and organic chemistry into a comprehensive portrait of a single rock and its parent body.