“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 and meteor astronomer Peter Jenniskens of the SETI Institute and NASA’s Ames Research Center in California’s Silicon Valley.

A Meteor Tracked Across the Northeast

The object that entered Earth’s atmosphere that day was roughly the size of a heavy airline bag and was traveling at 32,000 miles/h (14.4 kilometers per second). Sixty people across New York, New Jersey, Connecticut, Rhode Island and Pennsylvania reported seeing the meteor to the American Meteor Society. Sixteen people in New York and New Jersey also reported feeling the 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 rock was fragile and broke apart quickly as it traveled through the atmosphere. It disappeared from view at an altitude of 22 miles (35 kilometers). Soon afterward, Doppler weather radar at Newark Airport briefly detected an elongated cloud of falling pebbles extending from Staten Island into New Jersey.

Hillsborough sat near the far end of that debris path, where the largest pieces were expected to reach the ground. Only one meteorite was recovered, largely because it made its presence impossible to miss by striking a house.

The homeowner recalled what happened: “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 quickly documented the scene and protected the material from contamination. Wearing disposable gloves, he used aluminum foil to collect the meteorite fragments and placed them in glass jars.

An Exceptionally Rare Primitive Meteorite

Laboratory analysis showed that the recovered rock belonged to a primitive meteorite family known as CM-type carbonaceous chondrites. The “M” refers to the Mighei meteorite, which fell in Ukraine in 1889.

Paper coauthor Mike Zolensky, a meteoriticist at NASA’s Johnson Space Center in Houston, found that some parts of the Hillsborough meteorite had experienced more extensive alteration by water on its parent asteroid than scientists usually observe in CM2 carbonaceous chondrites.

The meteorite was classified as a CM1/2 carbonaceous chondrite, placing it between the petrographic CM1 and CM2 categories.

The Hillsborough event is only the 22nd observed fall involving a CM-type meteorite. More remarkably, it is 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. Every other witnessed CM fall has involved CM2 material, and 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,” said Jenniskens.

Evidence of Ancient Asteroid Brines

Scientists are particularly interested in how water influenced the chemistry of primitive asteroids. Another major group of primitive carbonaceous chondrites is known as CI, with the “I” referring to the Ivuna meteorite that fell in Tanzania in 1938.

Pristine samples related to this type have also been returned directly from space. JAXA’s Hayabusa 2 mission brought material back from asteroid Ryugu, while NASA’s OSIRIS-REx mission returned samples from asteroid Bennu. Those samples contain substantial evidence that briny fluids once existed just beneath the surfaces of their parent asteroids.

Zolensky and colleague JangMi Han discovered small CM1 fragments rich in salt inside the Hillsborough meteorite. Their findings suggest that the material came from a region near the surface of its parent asteroid, where liquid water evaporated and left behind increasingly concentrated salts.

The researchers are now identifying the specific salt minerals in the meteorite so they can compare them with similar materials found in samples returned from Ryugu and Bennu.

This salty chemistry could have important implications for understanding the chemical conditions that helped produce molecules relevant to life. Highly concentrated brines can keep phosphate dissolved in solution and can promote chemical reactions involving organic compounds and minerals that precipitate from solution.

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, England, 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.”

Researchers also detected a broad range of soluble organic compounds in the meteorite. The diversity of those compounds provides further evidence that the Hillsborough material experienced more extensive alteration by water than most other CM-type meteorites.

“A high fraction of compounds were the product of organic chemistry with minerals,” said organic mass spectrometry specialist Phil Schmitt-Kopplin of Technical University 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 also play important roles in living systems, including in blood and photosynthesis. Scientists found numerous amino acids among the soluble organic compounds in the Hillsborough meteorite as well. They were similar to amino acids previously detected in CM2 chondrites that experienced more moderate water alteration.

Astrobiologist Danny Glavin of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and researchers in Goddard’s Astrobiology Analytical Lab concluded that CM-type bodies could have supplied the early Earth with amino acids, carboxylic acids and other soluble organic molecules. That delivery may have contributed to the collection of prebiotic organic material that existed before life emerged.

Their analysis also indicates that the meteorite’s complex assortment of amino acids formed inside its parent body. Briny fluids likely helped drive at least some of that chemistry.

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, preserving the unusual material for future research.

“We are thrilled that nature delivered such a precious asteroid sample on our doorstep,” said curator Denton Ebel.

The discovery comes from researchers at the U.S. National Science Foundation National Solar Observatory (NSF NSO), the Max Planck Institute for Solar System Research (MPS) in Germany, and the High Altitude Observatory (HAO) in the USA. The team combined observations from the NSF Daniel K. Inouye Solar Telescope, the world’s largest solar telescope, with advanced computer simulations. Built and operated by the NSO in Hawaii, the telescope provided images detailed enough to expose plasma motions that had never previously been visible.

“To detect the vortices, we needed to resolve structures on the solar surface about 20 kilometers in size. That is at the limit of what even the world’s largest solar telescope and state-of-the-art simulations can achieve,” said MPS scientist and co-author of the new publication Michiel van Noort, who contributed to the observations as well as the data reduction and image restoration. The researchers used a broadband imaging camera provided by the Max-Planck-Institute for Solar System Research (MPS).

Tiny Whirlpools Along Solar Granules

The newly detected vortices appear along the boundaries of structures known as granules, which densely cover the Sun’s visible surface. Individual granules are typically between 500 and 2,000 kilometers across.

Together, they create the Sun’s granulation, a constantly changing pattern that resembles bubbles in a boiling liquid. The comparison is fitting because granulation is produced by moving plasma. Hot plasma rises from deeper inside the Sun, cools near the surface, and then sinks back down.

For the first time, scientists were able to resolve extremely fine, fringe-like structures along the edges of these granules. The structures repeatedly develop swirling motions that resemble ocean waves as they begin to break.

Some of these “fringes” measure only slightly more than 20 kilometers across. Observing something that small on the Sun is roughly equivalent to identifying a one euro coin from 180 kilometers away.

Instabilities in the Solar Plasma

The researchers believe these swirling flows are evidence of Kelvin-Helmholtz instabilities, a familiar phenomenon in fluid dynamics.

Kelvin-Helmholtz instabilities develop when two fluids move alongside one another at different speeds. The difference in velocity produces shear forces where the two flows meet. Small disturbances at that boundary can then grow into waves or swirling vortices.

The same basic process appears in many environments and across vastly different scales — for example, on the surfaces of lakes or in ocean waves, in cloud formation, in the atmospheres of the giant gas planets Jupiter and Saturn, and in the interaction of the solar wind with planetary magnetospheres.

At the boundaries of solar granules, neighboring layers of plasma also appear to travel at different speeds. Those conditions could provide exactly what is needed for Kelvin-Helmholtz instabilities to form.

Tiny Vortices Could Twist Magnetic Fields

The newly observed plasma vortices may offer an important clue to how the Sun stores and releases energy within its magnetic field, including through tiny bursts of radiation called nanoflares.

Current theories suggest that magnetic energy builds up as the Sun’s magnetic field lines become twisted and coiled — similar to the mechanical energy stored in a tightly coiled metal spring. As the twisting increases, the magnetic configuration becomes both highly energetic and unstable.

Eventually, that stored energy can be released through a process known as “magnetic reconnection.” During reconnection, twisted magnetic field lines snap open and reconnect in a different arrangement.

One major unanswered question has been what causes those magnetic field lines to become twisted in the first place.

The newly discovered vortices could supply part of the answer. Because the researchers find that these small whirlpools appear continuously wherever the magnetic field is sufficiently strong, the vortices could provide a persistent mechanism for twisting the Sun’s magnetic field lines.

A Possible Clue to the Sun’s Magnetic Cycle

The analysis also indicates that the mini-vortices are highly effective at mixing magnetized and non-magnetized plasma at the solar surface. That mixing could help magnetic fields move quickly from the surface upward into the Sun’s atmosphere.

Changes in the Sun’s magnetic field drive its roughly eleven-year activity cycle — which is exceptionally rapid on a cosmic scale. For the Sun’s magnetic “framework” to change this quickly, magnetic flux must be transported efficiently away through the solar atmosphere.

Current models have difficulty explaining how this diffusion can happen so rapidly. The newly identified vortices could provide an important piece of that puzzle as well.

“The newly discovered plasma vortices impressively demonstrate how minute processes — at the limit of what we can resolve using all available techniques — significantly determine the nature of our star,” said Sami K. Solanki, director of the MPS and co-author of the new publication.

The findings raise questions about public health advice that encourages people to reduce sweet-tasting foods as a way to combat overweight and obesity. The researchers argue that the more important targets may be sugar intake and energy-dense foods rather than sweetness itself.

Sweetness Intake Did Not Change Taste Preferences

The study was conducted by researchers at Wageningen University and Research in the Netherlands and Bournemouth University in the UK. The findings were published in the American Journal of Clinical Nutrition.

“People have a natural love of sweet taste which has led many organizations, including the World Health Organization, to offer dietary advice on reducing the amount of sweetness in our diets altogether,” said Katherine Appleton, Professor in Psychology at Bournemouth University and corresponding author for the study. “However, our results do not support this advice, which does not consider whether the sweet taste comes from sugar, low-calorie sweeteners, or natural sources,” she added.

Researchers recruited 180 participants and divided them into three groups. One group ate a diet containing a high amount of sweet-tasting food, another ate a diet with a low amount, and the third followed a diet with an average level of sweetness.

The sweet taste in the foods came from several sources, including sugar, naturally occurring sweetness, and low-calorie sweeteners. This distinction matters because foods can taste sweet for very different nutritional reasons. Fruit, for example, contains naturally occurring sugars along with vitamins, fiber, and other nutrients, while some processed foods may contain added sugar without offering the same nutritional benefits.

Six Months of Testing Found Little Difference

After one month, three months, and six months, participants were asked whether their liking for sweet foods or their perception of sweetness had changed.

Researchers also tracked body weight and collected blood and urine samples. These samples were used to look for changes in markers associated with diabetes risk and cardiovascular health. Such markers can help researchers assess whether a dietary change is affecting processes linked to blood sugar control, metabolism, or heart health.

At the end of the six-month trial, the researchers found no significant differences among the three groups in any of the measures they examined. People who ate more sweet-tasting foods did not appear to develop a stronger preference for sweetness, while those who ate fewer sweet foods did not appear to lose their taste for it.

Participants also tended to return on their own to their previous levels of sweet food consumption after the study ended.

Researchers Question Advice to Reduce Sweet Foods

Based on the results, the research team says public health organizations may need to reconsider recommendations that broadly target sweet-tasting foods as part of efforts to address overweight and obesity.

The researchers emphasize that sweetness and sugar are not the same thing. A food can taste sweet because it contains sugar, a low-calorie sweetener, or naturally occurring sugars. At the same time, some foods that do not taste especially sweet can still contain substantial amounts of sugar.

“It’s not about eating less sweet food to reduce obesity levels,” Professor Appleton said. “The health concerns relate to sugar consumption. Some fast-food items may not taste sweet but can contain high levels of sugar. Similarly, many naturally sweet products such as fresh fruit and dairy products can have health benefits. Public advice therefore needs to concentrate on how people can reduce the amount of sugar and energy-dense foods they consume,” she concluded.

Energy-dense foods contain a relatively large number of calories in a small amount of food. Many highly processed foods fall into this category because they can be rich in added sugars, fats, or both.

The study suggests that simply reducing exposure to sweet tastes may not be enough to change people’s preferences or improve the health measures examined over six months. Instead, the researchers say dietary guidance may be more useful when it focuses on the nutritional quality of foods, particularly their sugar and calorie content, rather than whether they taste sweet.