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Honolulu is pictured here beside a calm sea in 2017. A JPL technology recently detected and confirmed a tsunami up to 45 minutes prior to detection by tide gauges in Hawaii, and it estimated the speed of the wave to be over 580 miles per hour (260 meters per second) near the coast.NASA/JPL-Caltech A massive earthquake and subsequent tsunami off Russia in late July tested an experimental detection system that had deployed a critical component just the day before.
A recent tsunami triggered by a magnitude 8.8 earthquake off Russia’s Kamchatka Peninsula sent pressure waves to the upper layer of the atmosphere, NASA scientists have reported. While the tsunami did not wreak widespread damage, it was an early test for a detection system being developed at the agency’s Jet Propulsion Laboratory in Southern California.
Called GUARDIAN (GNSS Upper Atmospheric Real-time Disaster Information and Alert Network), the experimental technology “functioned to its full extent,” said Camille Martire, one of its developers at JPL. The system flagged distortions in the atmosphere and issued notifications to subscribed subject matter experts in as little as 20 minutes after the quake. It confirmed signs of the approaching tsunami about 30 to 40 minutes before waves made landfall in Hawaii and sites across the Pacific on July 29 (local time).
“Those extra minutes of knowing something is coming could make a real difference when it comes to warning communities in the path,” said JPL scientist Siddharth Krishnamoorthy.
Near-real-time outputs from GUARDIAN must be interpreted by experts trained to identify the signs of tsunamis. But already it’s one of the fastest monitoring tools of its kind: Within about 10 minutes of receiving data, it can produce a snapshot of a tsunami’s rumble reaching the upper atmosphere.
The dots in this graph indicate wave disturbances in the ionosphere as measured be-tween ground stations and navigation satellites. The initial spike shows the acoustic wave coming from the epicenter of the July 29 quake that caused the tsunami; the red squiggle shows the gravity wave the tsunami generated.NASA/JPL-Caltech The goal of GUARDIAN is to augment existing early warning systems. A key question after a major undersea earthquake is whether a tsunami was generated. Today, forecasters use seismic data as a proxy to predict if and where a tsunami could occur, and they rely on sea-based instruments to confirm that a tsunami is passing by. Deep-ocean pressure sensors remain the gold standard when it comes to sizing up waves, but they are expensive and sparse in locations.
“NASA’s GUARDIAN can help fill the gaps,” said Christopher Moore, director of the National Oceanic and Atmospheric Administration Center for Tsunami Research. “It provides one more piece of information, one more valuable data point, that can help us determine, yes, we need to make the call to evacuate.”
Moore noted that GUARDIAN adds a unique perspective: It’s able to sense sea surface motion from high above Earth, globally and in near-real-time.
Bill Fry, chair of the United Nations technical working group responsible for tsunami early warning in the Pacific, said GUARDIAN is part of a technological “paradigm shift.” By directly observing ocean dynamics from space, “GUARDIAN is absolutely something that we in the early warning community are looking for to help underpin next generation forecasting.”
How GUARDIAN works
GUARDIAN takes advantage of tsunami physics. During a tsunami, many square miles of the ocean surface can rise and fall nearly in unison. This displaces a significant amount of air above it, sending low-frequency sound and gravity waves speeding upwards toward space. The waves interact with the charged particles of the upper atmosphere — the ionosphere — where they slightly distort the radio signals coming down to scientific ground stations of GPS and other positioning and timing satellites. These satellites are known collectively as the Global Navigation Satellite System (GNSS).
While GNSS processing methods on Earth correct for such distortions, GUARDIAN uses them as clues.
SWOT Satellite Measures Pacific Tsunami The software scours a trove of data transmitted to more than 350 continuously operating GNSS ground stations around the world. It can potentially identify evidence of a tsunami up to about 745 miles (1,200 kilometers) from a given station. In ideal situations, vulnerable coastal communities near a GNSS station could know when a tsunami was heading their way and authorities would have as much as 1 hour and 20 minutes to evacuate the low-lying areas, thereby saving countless lives and property.
Key to this effort is the network of GNSS stations around the world supported by NASA’s Space Geodesy Project and Global GNSS Network, as well as JPL’s Global Differential GPS network that transmits the data in real time.
The Kamchatka event offered a timely case study for GUARDIAN. A day before the quake off Russia’s northeast coast, the team had deployed two new elements that were years in the making: an artificial intelligence to mine signals of interest and an accompanying prototype messaging system.
Both were put to the test when one of the strongest earthquakes ever recorded spawned a tsunami traveling hundreds of miles per hour across the Pacific Ocean. Having been trained to spot the kinds of atmospheric distortions caused by a tsunami, GUARDIAN flagged the signals for human review and notified subscribed subject matter experts.
Notably, tsunamis are most often caused by large undersea earthquakes, but not always. Volcanic eruptions, underwater landslides, and certain weather conditions in some geographic locations can all produce dangerous waves. An advantage of GUARDIAN is that it doesn’t require information on what caused a tsunami; rather, it can detect that one was generated and then can alert the authorities to help minimize the loss of life and property.
While there’s no silver bullet to stop a tsunami from making landfall, “GUARDIAN has real potential to help by providing open access to this data,” said Adrienne Moseley, co-director of the Joint Australian Tsunami Warning Centre. “Tsunamis don’t respect national boundaries. We need to be able to share data around the whole region to be able to make assessments about the threat for all exposed coastlines.”
To learn more about GUARDIAN, visit:
https://guardian.jpl.nasa.gov
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Artemis II NASA astronauts (left to right) Reid Wiseman, Victor Glover, and Christina Koch, and CSA (Canadian Space Agency) astronaut Jeremy Hansen stand in the white room on the crew access arm of the mobile launcher at Launch Pad 39B as part of an integrated ground systems test at Kennedy Space Center in Florida on Wednesday, Sept. 20, 2023. The test ensures the ground systems team is ready to support the crew timeline on launch day.NASA/Frank Michaux With Artemis II, NASA is taking the science of living and working in space beyond low Earth orbit. While the test flight will help confirm the systems and hardware needed for human deep space exploration, the crew also will be serving as both scientists and volunteer research subjects, completing a suite of experiments that will allow NASA to better understand how human health may change in deep space environments. Results will help the agency build future interventions, protocols, and preventative measures to best protect astronauts on future missions to the lunar surface and to Mars.
Science on Artemis II will include seven main research areas:
ARCHeR: Artemis Research for Crew Health and Readiness
NASA’s Artemis II mission provides an opportunity to explore how deep space travel affects sleep, stress, cognition, and teamwork — key factors in astronaut health and performance. While these effects are well-documented in low Earth orbit, they’ve never been fully studied during lunar missions.
Artemis II astronauts will wear wristband devices that continuously monitor movement and sleep patterns throughout the mission. The data will be used for real-time health monitoring and safety assessments, while pre- and post-flight evaluations will provide deeper insights into cognition, behavior, sleep quality, and teamwork in the unique environment of deep space and the Orion spacecraft.
The findings from the test flight will inform future mission planning and crew support systems, helping NASA optimize human performance for the next era of exploration on the Moon and Mars.
Immune Biomarkers
Saliva provides a unique window into how the human immune system functions in a deep space environment. Tracing changes in astronauts’ saliva from before, during, and after the mission will enable researchers to investigate how the human body responds to deep space in unprecedented ways.
Dry saliva will be collected before, during, and after the mission. It will be blotted onto specialized paper in pocket-sized booklets since equipment needed to preserve wet spit samples in space – including refrigeration – will not be available due to volume constraints. To augment that information, liquid saliva and blood samples will be collected before and after the mission.
NASA Astronaut Randy Bresnik prepares to collect a dry saliva sample aboard the International Space Station. The process, which helps scientists investigate how the immune system is affected by spaceflight and will be part of the Artemis II mission, involves blotting saliva onto special paper that’s stored in pocket-sized booklets.Credit: NASA With these wet and dry saliva samples, scientists will gain insights into how the astronauts’ immune systems are affected by the increased stresses of radiation, isolation, and distance from Earth during their deep space flight. They also will examine whether otherwise dormant viruses are reactivated in space, as has been seen previously on the International Space Station with viruses that can cause chickenpox and shingles.
The information gathered from this study, when combined with data from other missions, will help researchers develop ways to keep crew members safe and healthy as we explore farther and travel for longer periods on deep space missions.
AVATAR: A Virtual Astronaut Tissue Analog Response
AVATAR is another important component of NASA’s strategy to gain a holistic understanding of how the deep space environment affects humans. Scientists plan to use organ-on-a-chip technology during Artemis II, marking the first time these devices will be used beyond the Van Allen belts.
Roughly the size of a USB thumb drive, the chips will measure how individual astronauts respond to deep space stressors, including extreme radiation and microgravity. The organ chips will contain cells developed from preflight blood donations provided by crew members to create miniature stand-ins, or “avatars,” of their bone marrow. Bone marrow plays a vital role in the immune system and is particularly sensitive to radiation, which is why scientists selected it for this study.
An organ chip for conducting bone marrow experiments in space. Credit: Emulate
A key goal for this research is to validate whether organ chips can serve as accurate tools for measuring and predicting human responses to stressors. To evaluate this, scientists will compare AVATAR data with space station findings, as well as with samples taken from the crew before and after flight.
AVATAR could inform measures to ensure crew health on future deep space missions, including personalizing medical kits to each astronaut. For citizens on Earth, it could lead to advancements in individualized treatments for diseases such as cancer.
AVATAR is a demonstration of the power of public-private partnerships. It’s a collaboration between government agencies and commercial space companies: NASA, National Center for Advancing Translational Sciences within the National Institutes of Health, Biomedical Advanced Research and Development Authority, Space Tango, and Emulate.
Artemis II Standard Measures
The crew also will become the first astronauts in deep space to participate in the Spaceflight Standard Measures study, an investigation that’s been collecting data from participating crew members aboard the space station and elsewhere since 2018. The study aims to collect a comprehensive snapshot of astronauts’ bodies and minds by gathering a consistent set of core measurements of physiological response.
The crew will provide biological samples including blood, urine, and saliva for evaluating nutritional status, cardiovascular health, and immunological function starting about six months before their launch. The crew also will participate in tests and surveys evaluating balance, vestibular function, muscle performance, changes in their microbiome, as well as ocular and brain health. While in space, data gathering will include an assessment of motion sickness symptoms. After landing, there will be additional tests of head, eye, and body movements, among other functional performance tasks. Data collection will continue for a month after their return.
All this information will be available for scientists interested in studying the effects of spaceflight via request to NASA’s Life Sciences Data Archive. The results from this work could lead to future interventions, technologies, and studies that help predict the adaptability of crews on a Mars mission.
Radiation Sensors Inside Orion
During the uncrewed Artemis I mission, Orion was blanketed in 5,600 passive and 34 active radiation sensors. The information they gathered assured researchers Orion’s design can provide protection for crew members from hazardous radiation levels during lunar missions. That doesn’t mean that scientists don’t want more information, however.
Similar to Artemis I, six active radiation sensors, collectively called the Hybrid Electronic Radiation Assessors, will be deployed at various locations inside the Orion crew module. Crew also will wear dosimeters in their pockets. These sensors will provide warnings of hazardous radiation levels caused by space weather events made by the Sun. If necessary, this data will be used by mission control to drive decisions for the crew to build a shelter to protect from radiation exposure due to space weather.
Additionally, NASA has again partnered the German Space Agency DLR for an updated model of their M-42 sensor – an M-42 EXT – for Artemis II. The new version offers six times more resolution to distinguish between different types of energy, compared to the Artemis I version. This will allow it to accurately measure the radiation exposure from heavy ions which are thought to be particularly hazardous for radiation risk. Artemis II will carry four of the monitors, affixed at points around the cabin by the crew.
Collectively, sensor data will paint a full picture of radiation exposures inside Orion and provide context for interpreting the results of the ARCHeR, AVATAR, Artemis II Standard Measures, and Immune Biomarkers experiments.
Lunar Observations Campaign
The Artemis II crew will take advantage of their location to explore the Moon from above. As the first humans to see the lunar surface up close since 1972, they’ll document their observations through photographs and audio recordings to inform scientists’ understanding of the Moon and share their experience of being far from Earth. It’s possible the crew could be the first humans to see certain areas of the Moon’s far side, though this will depend on the time and date of launch, which will affect which areas of the Moon will be illuminated and therefore visible when the spacecraft flies by.
Spacecraft such as NASA’s Lunar Reconnaissance Orbiter have been surveying and mapping the Moon for decades, but Artemis II provides a unique opportunity for humans to evaluate the lunar surface from above. Human eyes and brains are highly sensitive to subtle changes in color, texture, and other surface characteristics. Having the crew observe the lunar surface directly – equipped with questions that scientists didn’t even know to ask during Apollo missions – could form the basis for future scientific investigations into the Moon’s geological history, the lunar environment, or new impact sites.
This visualization simulates what the crew of Artemis II might see out the Orion windows on the day of their closest approach to the Moon. It compresses 36 hours into a little more than a minute as it flies the virtual camera on a realistic trajectory that swings the spacecraft around the Moon’s far side. This sample trajectory is timed so that the far side is fully illuminated when the astronauts fly by, but other lighting conditions are possible depending on the exact Artemis II launch date. The launch is scheduled for no later than April of 2026. NASA Goddard/Ernie Wright
It will also offer the first opportunity for an Artemis mission to integrate science flight control operations. From their console in the flight control room in mission control, a science officer will consult with a team of scientists with expertise in impact cratering, volcanism, tectonism, and lunar ice, to provide real-time data analysis and guidance to the Artemis II crew in space. During the mission, the lunar science team will be located in mission control’s Science Evaluation Room at NASA’s Johnson Space Center in Houston.
Lessons learned during Artemis II will pave the way for lunar science operations on future missions.
CubeSats
Several additional experiments are hitching a ride to space onboard Artemis II in the form of CubeSats – shoe-box-sized technology demonstrations and scientific experiments. Though separate from the objectives of the Artemis II mission, they may enhance understanding of the space environment.
Technicians install the Korea AeroSpace Administration (KASA) K-Rad Cube within the Orion stage adapter inside the Multi-Payload Processing Facility at NASA’s Kennedy Space Center in Florida on Tuesday, Sept. 2, 2025. The K-Rad Cube, about the size of a shoebox, is one of the CubeSats slated to fly on NASA’s Artemis II test flight in 2026. Credit: NASA Four international space agencies have signed agreements to send CubeSats into space aboard the SLS (Space Launch System) rocket, each with their own objectives. All will be released from an adapter on the SLS upper stage into a high-Earth orbit, where they will conduct an orbital maneuver to reach their desired orbit.
ATENEA – Argentina’s Comisión Nacional de Actividades Espaciales will collect data on radiation doses across various shielding methods, measure the radiation spectrum around Earth, collect GPS data to help optimize future mission design, and validate a long-range communications link.
K-Rad Cube – The Korea Aerospace Administration will use a dosimeter made of material designed to mimic human tissue to measure space radiation and assess biological effects at various altitudes across the Van Allen radiation belt.
Space Weather CubeSat – The Saudi Space Agency will measure aspects of space weather, including radiation, solar X-rays, solar energetic particles, and magnetic fields, at a range of distances from Earth.
TACHELES – The Germany Space Agency DLR will collect measurements on the effects of the space environment on electrical components to inform technologies for lunar vehicles.
Together, these research areas will inform plans for future missions within NASA’s Artemis campaign. Through Artemis, NASA will send astronauts to explore the Moon for scientific discovery, economic benefits, and build the foundation for the first crewed missions to Mars.
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Earth (ESD) Earth Explore Explore Earth Home Agriculture Air Quality Climate Change Freshwater Life on Earth Severe Storms Snow and Ice The Global Ocean Science at Work Earth Science at Work Technology and Innovation Powering Business Multimedia Image Collections Videos Data For Researchers About Us 5 Min Read NASA Data, Trainings Help Uruguay Navigate Drought
Uruguay’s Paso Severino Reservoir, the primary water source for Montevideo, on June 13, 2023, captured by Landsat 9. Credits:
NASA Earth Observatory/ Wanmei Liang Lee esta historia en español aquí.
NASA satellite data and trainings helped Uruguay create a drought-response tool that its National Water Authority now uses to monitor reservoirs and guide emergency decisions. A similar approach could be applied in the United States and other countries around the world.
From 2018 to 2023, Uruguay experienced its worst drought in nearly a century. The capital city of Montevideo, home to nearly 2 million people, was especially hard hit. By mid-2023, Paso Severino, the largest reservoir and primary water source for Montevideo, had dropped to just 1.7% of its capacity. As water levels declined, government leaders declared an emergency. They began identifying backup supplies and asked: Was there water left in other upstream reservoirs — mainly used for livestock and irrigation — that could help?
That’s when environmental engineer Tiago Pohren and his colleagues at the National Water Authority (DINAGUA – Ministry of Environment) turned to NASA data and trainings to build an online tool that could help answer that question and improve monitoring of the nation’s reservoirs.
“Satellite data can inform everything from irrigation scheduling in the Great Plains to water quality management in the Chesapeake Bay,” said Erin Urquhart, manager of the water resources program at NASA Headquarters in Washington. “NASA provides the reliable data needed to respond to water crises anywhere in the world.”
Learning to Detect Water from Space
The DINAGUA team learned about NASA resources during a 2022 workshop in Buenos Aires, organized by the Interagency Science and Applications Team (ISAT). Led by NASA, the U.S. Army Corps of Engineers, and the U.S. Department of State, the workshop focused on developing tools to help manage water in the La Plata River Basin, which spans multiple South American countries including Uruguay.
At the workshop, researchers from NASA introduced participants to methods for measuring water resources from space. NASA’s Applied Remote Sensing (ARSET) program also provided a primer on remote sensing principles.
DINAGUA team supervisor Jose Rodolfo Valles León asks a question during a 2022 workshop in Buenos Aires. Other members of the Uruguay delegation — Florencia Hastings, Vanessa Erasun Rodríguez de Líma, Vanessa Ferreira, and Teresa Sastre (current Director of DINAGUA) — sit in the row behind. Organization of American States “NASA doesn’t just deliver data,” said John Bolten, NASA’s lead scientist for ISAT and chief of the Hydrological Sciences Laboratory at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “We collaborate with our partners and local experts to translate the data into information that is useful, usable, and relevant. That kind of coordination is what makes NASA’s water programs so effective on the ground, at home and around the world.”
The DINAGUA team brought ideas and provided guidelines to Pohren for a tool that applies Landsat and Sentinel satellite imagery to detect changes in Uruguay’s reservoirs. Landsat, a joint NASA-U.S. Geological Survey mission, provides decades of satellite imagery to track changes in land and water. The Sentinel missions, a part of the European Commission managed Copernicus Earth Observation program and operated by ESA (the European Space Agency), provide complementary visible, infrared, and microwave imagery for surface water assessments.
From a young age, Pohren was familiar with water-related challenges, as floods repeatedly inundated his relatives’ homes in his hometown of Montenegro, Brazil. It was extra motivation for him as he scoured ARSET tutorials and taught himself to write computer code. The result was a monitoring tool capable of estimating the surface area of Uruguay’s reservoirs over time.
A screenshot of the reservoir monitoring tool shows the Paso Severino’s surface water coverage alongside time-series data tracking its variations. Tiago Pohren The tool draws on several techniques to differentiate the surface water extent of reservoirs. These techniques include three optical indicators derived from the Landsat 8 and Sentinel-2 satellites:
Normalized Difference Water Index, which highlights water by comparing how much green and near-infrared light is reflected. Water absorbs infrared light, so it stands out clearly from land. Modified Normalized Difference Water Index, which swaps near-infrared with shortwave infrared to improve the contrast and reduce errors when differentiating between water and built-up or vegetated areas. Automated Water Extraction Index, which combines four types of reflected light — green, near-infrared, and two shortwave infrared bands — to help separate water from shadows and other dark features. From Emergency Tool to Everyday Asset
In 2023, the DINAGUA team used Pohren’s tool to examine reservoirs located upstream from Montevideo’s drinking water intake. But the data told a tough story.
“There was water available in other reservoirs, but it was a very small amount compared to the water demand of the Montevideo metropolitan region,” Pohren said. Simulations showed that even if all of the water were released, most of it would not reach the water intake for Montevideo or the Paso Severino reservoir.
Despite this news, the analysis prevented actions that might have wasted important resources for maintaining productive activities in the upper basin, Pohren said. Then, in August 2023, rain began to refill Uruguay’s reservoirs, allowing the country to declare an end to the water crisis.
From right to left: Tiago Pohren, Vanessa Erasun, and Florencia Hastings at the second ISAT workshop in March 2024. Organization of American States Though the immediate water crisis has passed, the tool Pohren created will be useful in the future in Uruguay and around the world. During an ISAT workshop in 2024, he shared his tool with international water resources managers with the hope it could aid their own drought response efforts. And DINAGUA officials still use it to identify and monitor dams, irrigation reservoirs, and other water bodies in Uruguay.
Pohren continues to use NASA training and data to advance reservoir management. He’s currently exploring an ARSET training on how the Surface Water and Ocean Topography (SWOT) mission will further improve the system by allowing DINAGUA to directly measure the height of water in reservoirs. He is also following NASA’s new joint mission with ISRO (the Indian Space Research Organization) called NISAR, which launched on July 30. The NISAR satellite will provide radar data that detects changes in water extent, regardless of cloud cover or time of day. “If a drought happens again,” Pohren said, “with the tools that we have now, we will be much more prepared to understand what the conditions of the basin are and then make predictions.”
Environmental engineer Tiago Pohren conducts a field inspection on the Canelón Grande reservoir, the second-largest reservoir serving Montevideo, during the drought. Tiago Pohren By Melody Pederson, Rachel Jiang
The authors would like to thank Noelia Gonzalez, Perry Oddo, Denise Hill, and Delfina Iervolino for interview support as well as Jerry Weigel for connecting with Tiago about the tool’s development.
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What Would It Take to Say We Found Life?
We call this the podium test. What would it take for you personally to confidently stand up in front of an international audience and make that claim? When you put it in that way, I think for a lot of scientists, the bar is really high.
So of course, there would be obvious things, you know, a very clear signature of technology or a skeleton or something like that. But we think that a lot of the evidence that we might encounter first will be much more subtle. For example, chemical signs of life that have to be detected above a background of abiotic chemistry. And really, what we see might depend a lot on where we look.
On Mars, for example, the long history of exploration there gives us a lot of context for what we might find. But we’re potentially talking about samples that are billions of years old in those cases, and on Earth, those kinds of samples, the evidence of life is often degraded and difficult to detect.
On the ocean worlds of our outer solar system, so places like Jupiter’s moon Europa and Saturn’s moon Enceladus, there’s the tantalizing possibility of extant life, meaning life that’s still alive. But potentially we’re talking about exceedingly small amounts of samples that would have to be analyzed with a relatively limited amount of instrumentation that can be carried from Earth billions of miles away.
And then for exoplanets, these are planets beyond our own solar system. Really, what we’re looking for there are very large magnitude signs of life that can be detectable through a telescope from many light-years away. So changes like the oxygenation of Earth’s atmosphere or changes in surface color.
So any one of those things, if they rose to the suspicion of being evidence of life, would be really heavily scrutinized in a very sort of specific and custom way to that particular observation. But I think there are also some general principles that we can follow. And the first is just: Are we sure we’re seeing what we think we’re seeing? Many of these environments are not very well known to us, and so we need to convince ourselves that we’re actually seeing a clear signal that represents what we think it represents.
Carl Sagan once said, “Life is the hypothesis of last resort,” meaning that we ought to work hard for such a claim to rule out alternative possibilities. So what are those possibilities? One is contamination. The spacecraft and the instruments that we use to look for evidence of life are built in an environment, Earth, that is full of life. And so we need to convince ourselves that what we’re seeing is not evidence of our own life, but evidence of indigenous life.
If that’s the case, we should ask, should life of the type we’re seeing live there? And finally, we need to ask, is there any other way than life to make that thing, any of the possible abiotic processes that we know and even the ones that we don’t know? And as you can imagine, that will be quite a challenge.
Once we have a piece of evidence in hand that we really do think represents evidence of life, now we can begin to develop hypotheses. For example, do we have separate independent lines of evidence that corroborate what we’ve seen and increase our confidence of life?
Ultimately, all of this has to be looked at hard by the entire scientific community, and in that sense, I think the really operative word in our question is we. What does it take to say we found evidence of life? Because really, the answer, I think, depends on the full scientific community scrutinizing and skepticizing this observation to finally say that we scientists, we as a community and we as humanity found life.
[END VIDEO TRANSCRIPT]
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