A meteor crossed the New York City region in broad daylight on July 16, 2024, creating a sonic boom as it passed south of the Statue of Liberty. Minutes later, a meteorite weighing more than two pounds crashed through the roof of a home in Hillsborough, New Jersey. An international team of scientists has analyzed the recovered fragments, revealing rare evidence of salty fluids, organic compounds and ancient chemical activity on the surface of a primitive asteroid. The findings were published in Science Advances.
“A forensic study of the fragments revealed that they contained preserved bits from near the surface of a primitive asteroid where it experienced concentrated salty fluids— a process not previously known from this type of proto-planet world,” said lead author Peter Jenniskens, a meteor astronomer with the SETI Institute and NASA’s Ames Research Center in California’s Silicon Valley.
Hillsborough Meteor Tracked Across the Northeast
The space rock that entered Earth’s atmosphere was approximately the size of a heavy airline bag and traveled at 32,000 miles per hour (14.4 kilometers per second). Sixty people in New York, New Jersey, Connecticut, Rhode Island and Pennsylvania reported seeing the meteor to the American Meteor Society. Another 16 witnesses in New York and New Jersey reported feeling its shockwave.
“Our cameras in Northford, Connecticut, and Douglassville, Pennsylvania, as well as a doorbell camera in Wayne, New Jersey, captured the meteor, and from that we measured its trajectory,” said American Meteor Society operations manager Mike Hankey. “The path traced back to low in the asteroid belt.”
The incoming asteroid fragment was fragile and rapidly broke apart while passing through Earth’s atmosphere. It vanished from view at an altitude of about 22 miles (35 kilometers). Shortly afterward, Doppler weather radar at Newark Airport detected an elongated cloud of falling pebbles stretching from Staten Island into New Jersey.
Hillsborough was near the far end of the predicted debris path, where the largest meteorite fragments were expected to land. Only one meteorite was recovered, largely because it announced its arrival by crashing through a house.
The homeowner described the impact: “I was at home at the time, heard a loud crash and found a hole in the ceiling of the master bedroom. I smelled a strong sulfur-like odor and saw many black fragments along with debris and black dust that covered my bed, carpet and surrounding areas.”
He immediately documented the scene and took steps to prevent contamination. Wearing disposable gloves, he collected the meteorite fragments with aluminum foil and stored them in glass jars.
An Exceptionally Rare Primitive Meteorite
Laboratory testing identified the Hillsborough meteorite as a primitive CM-type carbonaceous chondrite. The “M” refers to the Mighei meteorite, which fell in Ukraine in 1889.
Mike Zolensky, a paper coauthor and meteoriticist at NASA’s Johnson Space Center in Houston, found that portions of the Hillsborough meteorite had undergone more extensive water-related alteration on their parent asteroid than is typically seen in CM2 carbonaceous chondrites.
Scientists classified the meteorite as a CM1/2 carbonaceous chondrite, placing it between the petrographic CM1 and CM2 categories.
The Hillsborough meteorite represents only the 22nd observed fall of a CM-type meteorite. It is even rarer as just the second witnessed fall of a CM1/2 carbonaceous chondrite. The first was the Kolang meteorite, which fell in North Sumatra, Indonesia, in 2020. All other witnessed CM meteorite falls have involved CM2 material, while no CM1 meteorite fall has ever been observed.
“Thanks to the homeowner’s quick reaction, these are the most pristine CM1/2 meteorites we know of,” Jenniskens said.
Evidence of Ancient Asteroid Brines
Scientists are studying the Hillsborough meteorite to better understand how water shaped the chemistry of primitive asteroids. Another important group of primitive carbonaceous chondrites is called CI, with the “I” referring to the Ivuna meteorite, which fell in Tanzania in 1938.
Samples from related primitive asteroids have also been brought directly to Earth by space missions. Japan’s Hayabusa2 mission returned material from asteroid Ryugu, while NASA’s OSIRIS-REx mission collected samples from asteroid Bennu. Both samples contain substantial evidence that salty fluids once flowed just beneath the surfaces of their parent asteroids.
Zolensky and colleague JangMi Han discovered tiny CM1 fragments rich in salt within the Hillsborough meteorite. The finding suggests that this material originated near the surface of its parent asteroid, where liquid water evaporated and became increasingly concentrated with dissolved salts.
The research team is now working to identify the specific salt minerals in the Hillsborough meteorite. The results could help scientists compare the meteorite with samples returned from Ryugu and Bennu.
This chemistry may offer important clues about the conditions that helped form molecules connected to the origins of life. Highly concentrated brines can keep phosphate dissolved and encourage chemical reactions involving organic compounds and minerals that form as solutions evaporate.
Organic Molecules and Ingredients for Life
“Isotope studies of carbon and nitrogen suggest that primitive carbonaceous chondrites, including CM-types, delivered organic matter to the early Earth,” said cosmochemist Queenie Chan of Royal Holloway University of London and biogeochemist Nana Ogawa of the Biogeochemistry Research Center at the Japan Agency for Marine-Earth Science and Technology. “The Hillsborough meteorite contained 1.8% by weight of carbon and 0.07% of nitrogen, and had carbon and nitrogen isotopes typical for CM-type meteorites.”
Scientists also identified a wide variety of soluble organic compounds in the meteorite. The diversity of these molecules provides additional evidence that the Hillsborough material experienced more extensive water alteration than most other CM-type meteorites.
“A high fraction of compounds were the product of organic chemistry with minerals,” said Phil Schmitt-Kopplin, an organic mass spectrometry specialist at the Technical University of Munich. “We do not know if these magnesium organic compounds were contributed by brine chemistry or were simply left over from earlier impact shock processes.”
Organometallic compounds are essential to living systems, including processes involved in blood and photosynthesis. Researchers also found numerous amino acids among the soluble organic compounds in the Hillsborough meteorite. These amino acids resembled those previously identified in CM2 chondrites that experienced less extensive water alteration.
Astrobiologist Danny Glavin of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and scientists in Goddard’s Astrobiology Analytical Lab concluded that CM-type asteroids may have delivered amino acids, carboxylic acids and other soluble organic molecules to the early Earth. This delivery could have contributed to the reservoir of prebiotic organic material that existed before life emerged.
The analysis also indicates that the meteorite’s complex mixture of amino acids formed within its parent asteroid. Briny fluids likely helped drive at least some of those chemical reactions.
A Rare Asteroid Sample Preserved for Science
Some fragments of the Hillsborough meteorite will eventually be curated by the American Museum of Natural History in New York City. Their preservation will allow scientists to study this unusual asteroid material for years to come.
“We are thrilled that nature delivered such a precious asteroid sample on our doorstep,” said curator Denton Ebel.
Source: www.sciencedaily.com