The results show that kitchen sponges do shed measurable amounts of microplastics over time. However, the researchers found that the biggest environmental burden associated with hand washing dishes is not the plastic particles themselves. Instead, water use accounts for the vast majority of the overall impact.

Kitchen Sponges as a Source of Microplastics

Although kitchen sponges are used daily in millions of households, their role as a source of microplastics has received relatively little attention. The research team set out to measure how much plastic is released as sponges wear down during normal use and to evaluate the environmental consequences through a life cycle assessment (LCA).

To gather realistic data, the study combined laboratory testing with citizen science. Households in Germany and North America volunteered to use one of three sponge types as part of their regular dishwashing routines while documenting how the sponges were used.

Researchers weighed each sponge before and after use to determine how much material was lost over time. They also conducted controlled laboratory experiments using an automated testing system known as “SpongeBot,” which reproduces the mechanical stress that sponges experience during dishwashing.

How Much Microplastic Do Sponges Release?

The study found that every sponge tested lost material during use, resulting in the release of microplastics. Depending on the sponge type, annual emissions ranged from about 0.68 grams to 4.21 grams of microplastics per person.

Sponges made with lower amounts of plastic released significantly fewer particles than those with higher plastic content.

Citizen science played an important role in the project because participants used the sponges under real household conditions. This allowed researchers to capture realistic dishwashing habits and usage patterns, leading to more accurate estimates than laboratory testing alone could provide.

Water Consumption Has the Largest Environmental Impact

While the amount of microplastic released by an individual sponge may seem small, the totals become much larger when scaled up. The researchers estimated that if a particular sponge type were used in every German household, annual emissions could reach as much as 355 tonnes of microplastics.

Although wastewater treatment plants capture a large share of these particles, several tonnes could still enter rivers, lakes, oceans, and soils each year.

Even so, microplastics were not the primary driver of environmental damage in the study. The environmental assessment found that approximately 85 to 97 percent of the total impact of manual dishwashing comes from water consumption. Compared with water use, microplastic emissions contributed a much smaller share of overall ecosystem damage.

How Consumers Can Reduce Their Environmental Footprint

The researchers identified several practical steps consumers can take to lessen the environmental impact of washing dishes:

• Use less water while washing dishes, since this provides the greatest environmental benefit.
• Choose sponges with lower plastic content to reduce microplastic release.
• Keep sponges in use for longer periods, as extending their lifespan lowers overall resource consumption.

Research Team and Publication

The study involved researchers from the Institute of Organismic Biology (BIOB) at the University of Bonn, the Fraunhofer Institute for Environmental, Safety and Energy Technology UMSICHT, and Leiden University.

The findings were published in Environmental Advances in the paper From sink to sea: Microplastic release from kitchen sponges and potential environmental effects by Leandra Hamann, Christina Galafton, Peter T. Rühr, Alexander Blanke, and Nils Thonemann.

“What comes next is the first time this one-of-a-kind aircraft will fly supersonic,” said Cathy Bahm, project manager for NASA’s Low Boom Flight Demonstrator. “We are starting toward the mission conditions test point that X-59 was designed for.”

Following months of flight testing, the X-59 team reviewed its progress in late May and is now preparing for a new phase that will push the aircraft to greater altitudes and higher speeds. These flights are intended to show how the aircraft performs under the operating conditions required for NASA’s Quesst mission, which aims to collect data on quiet supersonic flight.

First Supersonic Flights Ahead

NASA expects the X-59 to exceed the speed of sound for the first time during test flights scheduled for early June. The aircraft is expected to fly at more than 630 mph at an altitude of about 43,000 feet, marking a major milestone in the program.

The aircraft will then attempt a “mission conditions” flight, reaching Mach 1.4 (925 mph) at approximately 55,000 feet. Those performance targets are important because they match the conditions NASA plans to use when flying the X-59 over U.S. communities. During those future flights, researchers will gather public feedback about the aircraft’s quieter sonic “thump” and evaluate how people respond to it.

Although the X-59 was designed to minimize the disruptive sonic boom typically associated with supersonic aircraft, these initial supersonic flights are not intended to demonstrate that capability. A conventional supersonic chase aircraft will accompany the X-59, and the louder sonic booms produced by the chase plane will mask any quieter sound generated by the experimental jet.

During supersonic testing this summer, the chase aircraft will also carry a specialized shock-sensing probe that will collect the first measurements of the X-59’s shock waves.

What NASA Learned From Earlier Flights

The aircraft’s first phase of testing successfully met a number of important objectives and produced valuable data for engineers.

After its maiden flight in October 2025, the X-59 underwent a planned maintenance period before returning to flight testing in March 2026. Since then, the aircraft has completed 14 additional flights and achieved several notable milestones, including:

• Completing its first gear swing, retracting its landing gear and revealing its distinctive aerodynamic profile in flight.
• Reaching altitudes of up to 43,000 feet and speeds approaching the sound barrier at Mach 0.95, roughly 627 mph.
• Conducting its first dual-flight day and later making multiple flights per day a routine part of testing.
• Transitioning from increasingly fast and high-altitude flights to slower, lower-altitude testing to evaluate performance across a wider range of operating conditions.

Information gathered during these flights has helped engineers evaluate key systems, including fuel delivery, hydraulics, environmental controls, and the aircraft’s eXternal Vision System. This unique camera-based system replaces a traditional forward-facing windshield by providing the pilot with a live display view ahead of the aircraft.

Teams also closely monitored how the X-59 performed during takeoffs, landings, and flight operations. Strain gauges installed throughout the aircraft measured structural loads and recorded how the airframe responded to various forces encountered during testing.

Expanding the Flight Envelope

The next set of flights will challenge the aircraft in a new way. Pilots will continue working through planned test points while engineers evaluate performance in true supersonic conditions.

“Flying at supersonic speeds is a major milestone for the X-59 team,” Bahm said. “Every step of envelope expansion brings us closer to demonstrating the quiet supersonic capability that is at the heart of the Quesst mission. Completing the first mission-conditions flight is especially meaningful — it’s the moment where we begin validating the aircraft in the environment it was designed for.”

Along with reaching mission conditions, the aircraft is expected to achieve its top planned performance targets during this testing phase, including a maximum speed of Mach 1.6 (1,218 mph) and a maximum altitude of 60,000 feet.

Even so, not every flight will take place at supersonic speed. Engineers will continue conducting a mix of subsonic and lower-altitude flights to monitor the aircraft’s behavior under a variety of conditions.

“These flights not only deepen our confidence in the X-59’s performance — they mark our progression toward the future phases of the mission that will ultimately help shape the future of supersonic travel,” Bahm said.

Preparing for Phase 2 of the Quesst Mission

All flights completed so far, along with the upcoming test campaign, are part of Phase 1 of NASA’s Quesst mission. This stage focuses on proving the aircraft’s performance and airworthiness.

Some flights will also involve the early use of specialized equipment, including a probe mounted on one of NASA’s F-15 research aircraft. The instrument is designed to measure the X-59’s unique shock wave signature.

The information collected during these early measurement flights will help engineers prepare for Quesst Phase 2, scheduled to begin later this year. During that stage, teams will directly measure the aircraft’s supersonic flight signature to confirm that it is producing the quiet supersonic thump it was designed to generate.

“Aviation pioneer Otto Lilienthal said, ‘To design a flying machine is nothing. To build one is something. But to fly is everything.’ The 15 X-59 flights we’ve accomplished since March have been everything to this team and the mission,” Bahm said. “Every flight has pushed the boundaries of what’s possible, steadily expanding the envelope and strengthening our confidence in the aircraft.”

However, Bahm emphasized that the team remains focused on the work ahead.

“As we look ahead to the upcoming flights, we’re poised to open the envelope even further — moving boldly toward the mission test point this aircraft was built to achieve,” Bahm said. “Flying supersonic and reaching these milestones isn’t just progress; it’s the realization of years of perseverance, innovation, and teamwork. Each step brings us closer to Phase 2, and to the future of commercial supersonic flight.”

What makes Roman especially exciting is where it will look. Most exoplanet discoveries to date have come from relatively nearby regions of the galaxy. Roman, however, will search largely unexplored areas of the Milky Way, offering a much broader view of planetary systems across our galaxy.

“Our galaxy is home to a variety of different environments, but when it comes to hunting for exoplanets, we’ve really only explored one: our own neighborhood,” said Elisa Quintana, an exoplanet researcher at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Quintana leads a team focused on building software and simulations to help prepare for Roman’s exoplanet transit observations. “Roman will extend the search far enough to encompass other galactic habitats, which could help us learn how planet formation varies across different regions of the Milky Way.”

Today, most known exoplanets are located within a few thousand light years of Earth. One of Roman’s primary surveys will look far beyond that range, examining stars through the Milky Way’s densely packed central bulge and extending all the way to the far side of the galaxy.

Searching the Milky Way for New Worlds

Roman will continuously monitor stars across a large section of the Milky Way, looking for changes in their brightness.

One technique relies on planetary transits. When a planet passes in front of its star from our perspective, it blocks a small amount of starlight, causing the star to dim temporarily.

The telescope will also use a second technique called microlensing. In these events, the gravity of a foreground star and any accompanying planets magnifies the light of a more distant background star, briefly making it appear brighter.

Each method is sensitive to different kinds of planets.

The transit technique, which is expected to uncover roughly 100,000 worlds, is particularly effective at detecting large, extremely hot planets. These planets block more light from their stars and complete their orbits more frequently, making them easier to spot.

Microlensing, which is expected to reveal more than 1,000 worlds, excels at finding planets farther from their stars, including systems that resemble our own solar system. It can detect planets as small as Earth and Mars, both within habitable zones and at greater distances from their stars. Many of these worlds are extremely difficult, or even impossible, to find using other detection methods.

Together, these complementary approaches will allow scientists to investigate how planets form throughout the galaxy, including in the region where our own solar system may have originated.

Clues to Earth’s Origins

Today, our solar system lies about 27,000 light years from the center of the Milky Way. Researchers believe it likely formed roughly 10,000 light years closer to the galactic center before gradually moving outward to its current location.

Evidence for this idea comes largely from the Sun’s chemical composition.

Astronomers use the term heavy elements to describe all elements other than hydrogen and helium, which were produced shortly after the universe formed. Heavier elements are created inside stars and become more abundant over time as successive generations of stars live and die.

Stars located in the galaxy’s outer regions generally contain fewer heavy elements. By contrast, stars in the galactic bulge are older and tend to be richer in elements such as silicon, oxygen, and magnesium.

These chemical differences may influence the types of planets that form around stars. Some systems could produce larger planets, rockier worlds, or perhaps more planets overall. In some cases, stellar composition may even affect whether planets form at all.

Astronomers have already found evidence that such relationships exist among nearby stars.

“Stars with more heavy elements tend to host more planets, especially giant ones,” said Robby Wilson, a postdoctoral fellow at NASA Goddard, who led a study about Roman’s expected transiting planet yield.

By examining entirely different populations of stars and planets across the Milky Way, Roman could greatly expand these studies and help reveal how common planetary systems like our own really are.

“Roman will be especially powerful because it will observe hundreds of millions of distant stars, letting scientists compare faraway planet populations to those found nearby,” said Wilson. “All of that data will give us a lot to comb through, so we’re prepping by creating synthetic data, detecting simulated planets, and using machine learning to filter out false positives. That way we’ll be ready to go right away when real data comes pouring in.”

All data collected by Roman will be publicly available, allowing researchers and citizen scientists alike to participate in the search for new worlds.

Studying Alien Atmospheres and Weather

Roman could also provide atmospheric information for thousands of the transiting planets it discovers.

“Roman won’t analyze atmospheres in the same in-depth way as missions like NASA’s James Webb Space Telescope, but it will gather different information on a much larger scale,” Wilson said.

While the James Webb Space Telescope focuses on detailed chemical analyses of individual planets, Roman will examine broader temperature and climate patterns across thousands of worlds. This large statistical dataset could identify important trends and help guide future observations by Webb and other observatories.

One area of focus will be “hot Jupiters,” giant planets roughly the size of Jupiter that orbit extremely close to their stars. Since Jupiter is about 11 times wider than Earth, these worlds are enormous and often complete an orbit in just a few days. Their high temperatures allow them to emit detectable infrared radiation.

Roman’s infrared instruments will be able to observe these glowing planets and study how their brightness changes over time.

When a hot Jupiter passes in front of its star, astronomers see one dip in brightness. A second, smaller dip occurs when the planet moves behind the star and its light is temporarily blocked.

“That secondary dip tells us how bright, and therefore how hot, the planet is,” said Wilson. “By tracking how the planet’s brightness changes over its orbit, Roman can also see differences between the day side and night side, and even detect shifts in where the hottest region is on the planet. That tells us about atmospheric winds and heat circulation.”

A New Era for Exoplanet Discovery

NASA’s Kepler mission transformed exoplanet science by monitoring roughly 100,000 stars and demonstrating that planets are extraordinarily common throughout the Milky Way.

“NASA’s now-retired Kepler mission’s survey of 100,000 stars revolutionized the field of exoplanets over a decade ago, and taught us that planets are even more common than stars in our galaxy,” said Jorge Martínez-Palomera, an astronomer at NASA Goddard who is helping prepare for Roman’s exoplanet data.

Roman is expected to take that legacy much further. Its galactic bulge survey alone will observe approximately 100 million stars while exploring regions of the Milky Way that remain largely uncharted.

“Roman’s galactic bulge survey will observe around 100 million stars and probe underexplored areas of our galaxy, which will provide a foundational dataset that will likewise revolutionize what we know about other worlds and our place in the Universe.”

The findings were published in two papers in the same issue of Nature and challenge decades of assumptions about the thymus. The results indicate that the organ remains important throughout adulthood and could eventually help guide disease prevention strategies and cancer treatment decisions.

“The thymus has been overlooked for decades and may be a missing piece in explaining why people age differently, and why cancer treatments fail in some patients,” said Hugo Aerts, PhD, corresponding author on the papers and director of the Artificial Intelligence in Medicine (AIM) Program at Mass General Brigham. “Our findings suggest thymic health deserves much more attention and may open new avenues for understanding how to protect the immune system as we age.”

What the Thymus Does

Located in the chest, the thymus helps train T cells, a type of immune cell that helps defend the body against infections and disease. Because the organ gradually shrinks after puberty and produces fewer new T cells over time, many scientists assumed it played only a limited role in adult health.

As a result, the thymus has received relatively little attention in large population studies. Earlier research connected T cell diversity to aging and declining immune function, but those studies were typically small and focused on blood samples.

The new research took a much broader approach. Investigators analyzed data from more than 25,000 adults participating in a national lung cancer screening trial, along with more than 2,500 people enrolled in the Framingham Heart Study, a long-running study that tracks the health of generally healthy adults.

AI Reveals Links to Longevity and Disease Risk

Using artificial intelligence (AI) to evaluate routine CT scans, the researchers measured the size, structure, and composition of the thymus. From those measurements, they created a “thymic health” score.

People with higher thymic health scores experienced significantly better outcomes. Compared with individuals who had poorer thymic health, they had about a 50% lower risk of death from any cause, a 63% lower risk of death from cardiovascular disease, and a 36% lower risk of developing lung cancer. These relationships remained strong even after accounting for age and other health factors.

The researchers believe that declines in thymic health may reduce T cell diversity, making it harder for the immune system to recognize and respond to new threats such as cancer and other diseases.

Their analysis also identified several factors associated with poorer thymic health, including chronic inflammation, smoking, and higher body weight. These findings suggest that lifestyle factors and ongoing inflammation may affect the immune system’s ability to remain resilient over time.

Thymus Health and Cancer Immunotherapy

In a separate study, the team examined CT scans and clinical outcomes from more than 1,200 cancer patients treated with immunotherapy.

The results showed that patients with healthier thymuses tended to respond better to treatment. They faced about a 37% lower risk of cancer progression and a 44% lower risk of death, even after researchers adjusted for differences in patients, tumors, and treatment approaches.

According to the researchers, these findings highlight a potentially important but previously underrecognized role for the thymus in determining how effectively modern cancer immunotherapies work.

More Research Needed

The scientists emphasize that additional studies will be needed to confirm the results. They also note that the imaging technique used to measure thymic health is not yet ready for routine use in clinical practice.

Although lifestyle factors were associated with thymic health, the studies did not investigate whether changing those factors can directly improve thymus function.

The research team is continuing to explore other influences on thymic health. One ongoing study is examining whether unintended radiation exposure to the thymus during lung cancer treatment could affect patient outcomes.

“Improving our understanding and monitoring of thymic health could eventually help physicians better assess disease risk and guide treatment decisions,” said Aerts.

In addition to Aerts, study co-authors of the overall adult health paper include Simon Bernatz, Vasco Prudente, Suraj Pai, Asbjørn Kjær, Yumeng Cao, Jiachen Chen, Asya Lyass, PhD, Borek Foldyna, Leonard Nürnberg, Christopher Abbosh, Charles Swanton, Mariam Jamal-Hanjani, MD, PhD, Michael T. Lu, Joanne M. Murabito, Kathryn L. Lunetta, and Nicolai J Birkbak.

Aerts’ co-authors of the immunotherapy outcomes paper include Simon Bernatz, Vasco Prudente, Suraj Pai, Asbjørn Kjær, Alessandro Di Federico, Andrew Rowan, Selvaraju Veeriah, Lars Dyrskjøt, Leonard Nürnberg, Joao V. Alessi, Patrick A. Ott, Elad Sharon, Allan Hackshaw, Nicholas McGranahan, Christopher Abbosh, Raymond H. Mak, Danielle Bitterman, Mark Awad, Biagio Ricciuti, Charles Swanton, Mariam Jamal-Hanjani, and Nicolai J Birkbak, PhD.

This research received funding support from the National Institutes of Health, European Research Council, Deutsche Forschungsgemeinschaft (DFG, German Research Foundation), Lundbeck Foundation, Novo Nordisk Foundation, and Savvaerksejer Jeppe Juhl og Hustru Ovita Juhl Research Stipend.