Hundreds of thousands of U.S. nonprofits provide vital services, such as running food banks and youth programs, supporting public health initiatives and helping unemployed people find new jobs. Although this work helps sustain local communities, obtaining the money and staff they require is a constant struggle for many of these groups.

That’s where AmeriCorps often comes in. The independent federal agency for national service and volunteerism has facilitated the work of approximately 200,000 people a year, placing them through partnerships with thousands of nonprofits that provide tutoring, disaster relief and many other important services.

But Americorps’ fate is now uncertain. In April 2025, the Trump administration canceled more than 1,000 grants, suddenly ending the stipends that were supporting more than 32,000 AmeriCorps volunteers. On June 5, a judge ordered that these grants be restored in Washington D.C. and 24 states in response to a lawsuit they had filed. The judge also ordered that all volunteers who had been deployed in those places be reinstated “if they are willing and able to return.”

The Trump administration has also put most of AmeriCorps administrative staff on leave and indicated that it wants to eliminate the independent agency, along with its US$1.2 billion annual budget. AmeriCorps doesn’t appear in a detailed 2026 budget request the administration released on May 30.

I’m a sociology and public affairs professor who has studied nonprofits and volunteering for decades. My research suggests that dismantling AmeriCorps would harm the organizations that rely on national service members and take a toll on the communities that benefit from their work.

What AmeriCorps does

AmeriCorps traces its roots to the mid-1960s, when Volunteers in Service to America, known as VISTA, was founded as a domestic counterpart to the Peace Corps. Several earlier service programs were consolidated when Congress passed the National and Community Service Trust Act in 1993. AmeriCorps was officially launched in 1994 – and VISTA became one of its programs.

Since then, AmeriCorps members have built housing and infrastructure, delivered disaster relief, tutored in low-income schools, provided health care and helped older adults age with dignity in both urban and rural communities across the nation.

AmeriCorps includes a variety of programs, each designed to address specific public needs. Some AmeriCorps volunteers provide direct services, such as tutoring, food delivery and in disaster response efforts. Others focus on building the long-term capacity of local nonprofits through volunteer recruitment, fundraising strategy and community outreach.

AmeriCorps volunteers, whom the agency calls “members,” are placed in thousands of nonprofits, schools and local agencies. Many of them are recent college graduates or early-career professionals. Some programs specifically ask people over 55 to serve. Those “senior” volunteers support children through the Foster Grandparents program, volunteer for organizations or assist other older people through the Senior Companions program.

Many AmeriCorps volunteers are paid a modest allowance for this work that runs about $500 per week. AmeriCorps senior volunteers receive smaller sums in hourly stipends to offset the costs of volunteering.

Helping nonprofits gain traction

AmeriCorps has long funded research that assesses its impact.

One such study found that every dollar invested in national service generates $11.80 in benefits for society, such as higher earnings, better mental and physical health, and economic growth. Additionally, every federal dollar spent on national service produces $17.30 in savings across other government programs through reductions in public assistance, health and criminal justice spending.

As part of AmeriCorps’ research grants program, I have received funding to study civic engagement and AmeriCorps programming.

In one of those studies, which I conducted with two former colleagues at the University of Texas at Austin in 2021, we found that VISTA volunteers were able to help nonprofits gain volunteers. After two years, an organization with that support had 71% more volunteers than those that didn’t participate in the VISTA program.

We also found that the longer a nonprofit had a staffer supported by the VISTA program, the more its overall pool of volunteers increased.

Nonprofits with VISTA volunteers also had three times as many donations two years later, compared with nonprofits without VISTA service members. But the total value of donations the nonprofit obtained didn’t always rise. That is, we found that VISTA builds people power, but not necessarily fundraising revenue.

Findings like these indicate that AmeriCorps hasn’t just helped the people it serves or the people who volunteer through the program. It also strengthens nonprofits and increases engagement within local communities, reinforcing the civic fabric that knits communities together.

As members of Congress and the White House decide whether to preserve AmeriCorps, I hope they consider the evidence that demonstrates this worthwhile program’s positive impact.

Pamela Paxton, Professor of Sociology, The University of Texas at Austin

This article is republished from The Conversation under a Creative Commons license. Read the original article.

The search for life beyond Earth is a key driver of modern astronomy and planetary science. The U.S. is building multiple major telescopes and planetary probes to advance this search. However, the signs of life – called biosignatures – that scientists may find will likely be difficult to interpret. Figuring out where exactly to look also remains challenging.

I am an astrophysicist and astrobiologist with over 20 years of experience studying extrasolar planets – which are planets beyond our solar system.

My colleagues and I have developed a new approach that will identify the most interesting planets or moons to search for life and help interpret potential biosignatures. We do this by modeling how different organisms may fare in different environments, informed by studies of limits of life on Earth.

New telescopes to search for life

Astronomers are developing plans and technology for increasingly powerful space telescopes. For instance, NASA is working on its proposed Habitable Worlds Observatory, which would take ultrasharp images that directly show the planets orbiting nearby stars.

My colleagues and I are developing another concept, the Nautilus space telescope constellation, which is designed to study hundreds of potentially Earthlike planets as they pass in front of their host stars.

These and other future telescopes aim to provide more sensitive studies of more alien worlds. Their development prompts two important questions: “Where to look?” and “Are the environments where we think we see signs of life actually habitable?”

The strongly disputed claims of potential signs of life in the exoplanet K2-18b, announced in April 2025, and previous similar claims in Venus, show how difficult it is to conclusively identify the presence of life from remote-sensing data.

When is an alien world habitable?

Oxford Languages defines “habitable” as “suitable or good enough to live in.” But how do scientists know what is “good enough to live in” for extraterrestrial organisms? Could alien microbes frolic in lakes of boiling acid or frigid liquid methane, or float in water droplets in Venus’ upper atmosphere?

To keep it simple, NASA’s mantra has been “follow the water.” This makes sense – water is essential for all Earth life we know of. A planet with liquid water would also have a temperate environment. It wouldn’t be so cold that it slows down chemical reactions, nor would it be so hot that it destroys the complex molecules necessary for life.

However, with astronomers’ rapidly growing capabilities for characterizing alien worlds, astrobiologists need an approach that is more quantitative and nuanced than the water or no-water classification.

A community effort

As part of the NASA-funded Alien Earths project that I lead, astrobiologist Rory Barnes and I worked on this problem with a group of experts – astrobiologists, planetary scientists, exoplanet experts, ecologists, biologists and chemists – drawn from the largest network of exoplanet and astrobiology researchers, NASA’s Nexus for Exoplanet System Science, or NExSS.

Over a hundred colleagues provided us with ideas, and two questions came up often:

First, how do we know what life needs, if we do not understand the full range of extraterrestrial life? Scientists know a lot about life on Earth, but most astrobiologists agree that more exotic types of life – perhaps based on different combinations of chemical elements and solvents – are possible. How do we determine what conditions those other types of life may require?

Second, the approach has to work with incomplete data. Potential sites for life beyond Earth – “extrasolar habitats” – are very difficult to study directly, and often impossible to visit and sample.

For example, the Martian subsurface remains mostly out of our reach. Places like Jupiter’s moon Europa’s and Saturn’s Moon Enceladus’ subsurface oceans and all extrasolar planets remain practically unreachable. Scientists study them indirectly, often only using remote observations. These measurements can’t tell you as much as actual samples would.

To make matters worse, measurements often have uncertainties. For example, we may be only 88% confident that water vapor is present in an exoplanet’s atmosphere. Our framework has to be able to work with small amounts of data and handle uncertainties. And, we need to accept that the answers will often not be black or white.

A new approach to habitability

The new approach, called the quantitative habitability framework, has two distinguishing features:

First, we moved away from trying to answer the vague “habitable to life” question and narrowed it to a more specific and practically answerable question: Would the conditions in the habitat – as we know them – allow a specific (known or yet unknown) species or ecosystem to survive?

Even on Earth, organisms require different conditions to survive – there are no camels in Antarctica. By talking about specific organisms, we made the question easier to answer.

Second, the quantitative habitability framework does not insist on black-or-white answers. It compares computer models to calculate a probabilistic answer. Instead of assuming that liquid water is a key limiting factor, we compare our understanding of the conditions an organism requires (the “organism model”) with our understanding of the conditions present in the environment (the “habitat model”).

Both have uncertainties. Our understanding of each can be incomplete. Yet, we can handle the uncertainties mathematically. By comparing the two models, we can determine the probability that an organism and a habitat are compatible.

As a simplistic example, our habitat model for Antarctica may state that temperatures are often below freezing. And our organism model for a camel may state that it does not survive long in cold temperatures. Unsurprisingly, we would correctly predict a near-zero probability that Antarctica is a good habitat for camels.

We had a blast working on this project. To study the limits of life, we collected literature data on extreme organisms, from insects that live in the Himalayas at high altitudes and low temperatures to microorganisms that flourish in hydrothermal vents on the ocean floor and feed on chemical energy.

We explored, via our models, whether they may survive in the Martian subsurface or in Europa’s oceans. We also investigated if marine bacteria that produce oxygen in Earth’s oceans could potentially survive on known extrasolar planets.

Although comprehensive and detailed, this approach makes important simplifications. For example, it does not yet model how life may shape the planet, nor does it account for the full array of nutrients organisms may need. These simplifications are by design.

In most of the environments we currently study, we know too little about the conditions to meaningfully attempt such models – except for some solar system bodies, such as Saturn’s Enceladus.

The quantitative habitability framework allows my team to answer questions like whether astrobiologists might be interested in a subsurface location on Mars, given the available data, or whether astronomers should turn their telescopes to planet A or planet B while searching for life. Our framework is available as an open-source computer model, which astrobiologists can now readily use and further develop to help with current and future projects.

If scientists do detect a potential signature of life, this approach can help assess if the environment where it is detected can actually support the type of life that leads to the signature detected.

Our next steps will be to build a database of terrestrial organisms that live in extreme environments and represent the limits of life. To this data, we can also add models for hypothetical alien life. By integrating those into the quantitative habitability framework, we will be able to work out scenarios, interpret new data coming from other worlds and guide the search for signatures of life beyond Earth – in our solar system and beyond.

Daniel Apai, Associate Dean for Research and Professor of Astronomy and Planetary Sciences, University of Arizona

This article is republished from The Conversation under a Creative Commons license. Read the original article.