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4 Min Read Washington State Student Wins 2025 NASA Art Contest
“My Wonders with You” by Dahyun Jung, 2025 NASA Student Art Contest grand prize winner Credits: NASA/Dahyun Jung A Washington state high school student with a passion for art, space exploration, and a curiosity about the possibility of life on other planets earned the grand prize for the 2025 NASA Student Art Contest.
Dahyun Jung’s winning piece, titled “My Wonders with You,” shows a child seated on the roof of a barn, their arm draped around a dog, watching a space shuttle blast off in the distance. The two are joined by three extraterrestrial beings that also watch in awe. Jung was a high school senior during the submission period for the 2025 competition, which was December 1 through December 31, 2024. The theme for the 2025 art contest was “Our Wonder Changes the World.”
“My Wonders with You” by Dahyun Jung, 2025 NASA Student Art Contest grand prize winner
Credit: NASA/Dahyun JungNASA/Dahyun Jung “The theme immediately sparked memories of the moment I first saw a NASA spacecraft launch into space,” Jung said. “That experience filled me with awe and endless questions—especially about how aliens might view our efforts to explore the cosmos. I began imagining what future space missions might look like if we ever made contact with extraterrestrial life. That was the moment everything clicked—the exact moment when imaginations started to fill up the tiny world in my head. I knew exactly what I wanted to draw!”
Jung said art and crafting have been a special part of her life since childhood. She enjoys using a variety of materials to create everything from drawings and paintings to keychains and crochet dolls.
“I’ve always loved drawing, but it was in middle school that I really began to delve into it more deeply,” Jung said. “I see everything that passes through my hands as a form of art.”
I see everything that passes through my hands as a form of art.
Dahyun Jung
2025 NASA Student Art Contest grand prize winner
“A Marsbulous Future” by Chloe Ji, 2025 NASA Student Art Contest First Place Winner, 1st Grade Division
Credit: NASA/Chloe JiNASA/Chloe Ji Jung was one of more than 2,300 kindergarten through 12th grade students from across the United States and its territories who participated in the 2025 art contest, a record-breaking number. Kristina Cors, art contest coordinator at NASA’s Langley Research Center in Hampton, Virginia, said, “This contest gives the students a way to connect their passion for art with science, technology, engineering, and mathematics (STEM) and hopefully inspires them to continue exploring those connections throughout their lives.”
Jung is no stranger to the art contest. She said she first participated in 2022.
“Returning to the contest in 2025 felt both nostalgic and thrilling as I came back with improved techniques, more experience, and a fresh new idea that fit this year’s theme,” she said.
Jung used Procreate, a digital illustration and painting app, to create her award-winning work.
“For this piece, I used my customized brush in Procreate,” Jung said. “The biggest merit of using a digital platform for drawing is the variety of textured brushes they offer. They allowed me to vividly illustrate various elements—like the sky, the rocket’s exhaust plume, hair, and roof—each with its own texture and detail.”
Dahyun Jung, grand prize winner of the 2025 NASA Student Art Contest, holds her winning piece “My Wonders with You.”
Credit: NASA/Dahyun JungNASA/Dahyun Jung Jung’s artwork brought to life her own enthusiasm regarding NASA’s work advancing space exploration, aeronautics, and science.
“I’ve always been fascinated by NASA’s commitment to pushing boundaries—especially in space exploration,” Jung said. “Space feels like an undiscovered world, full of endless possibilities, but only a few have had the chance to access it. In many ways, NASA’s work mirrors how I always push creative boundaries in my own art. I’ve always dreamed of traveling to space, and it’s that sense of wonder that inspired my piece.”
Jung said she hopes her artwork can help to inspire awe and stir imagination in others.
“Changing the World” by Jane Lee, 2025 NASA Student Art Contest First Place Winner, 8th Grade Division
Credit: NASA/Jane LeeNASA/Jane Lee “I want my artwork to be the starting point of all wonders—a spark that takes people back to their childhood, when dreams were bold and limitless,” Jung said. “I hope it rekindles that sense of passion, whatever it may be, and encourages others to dare to dream again.
To view a complete list of winners by grade, please click here.
To view all 2025 art contest entries, please click here.
Brittny McGraw
NASA Langley Research Center
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Joe Atkinson
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Explore This Section Perseverance Home Mission Overview Rover Components Mars Rock Samples Where is Perseverance? Ingenuity Mars Helicopter Mission Updates Science Overview Objectives Instruments Highlights Exploration Goals News and Features Multimedia Perseverance Raw Images Images Videos Audio More Resources Mars Missions Mars Sample Return Mars Perseverance Rover Mars Curiosity Rover MAVEN Mars Reconnaissance Orbiter Mars Odyssey More Mars Missions Mars Home 3 min read
To See the World in a Grain of Sand: Investigating Megaripples at ‘Kerrlaguna’
NASA’s Mars Perseverance rover acquired this image of inactive megaripples at “Kerrlaguna,” Perseverance’s latest target of exploration, on Aug. 13, 2025. The rover acquired the image using its Right Mastcam-Z camera, one of a pair of cameras located high on the rover’s mast, on Sol 1593 — or, Martian day 1,593 of the Mars 2020 mission — at the local mean solar time of 12:05:13. NASA/JPL-Caltech/ASU Written by Athanasios Klidaras, Ph.D. candidate at Purdue University
On Mars, the past is written in stone — but the present is written in sand. Last week, Perseverance explored inactive megaripples to learn more about the wind-driven processes that are reshaping the Martian landscape every day.
After wrapping up its investigation at the contact between clay and olivine-bearing rocks at “Westport,” Perseverance is journeying south once more. Previously, attempts were made to drive uphill to visit a new rock exposure called “Midtoya.” However, a combination of the steep slope and rubbly, rock-strewn soil made drive progress difficult, and after several attempts, the decision was made to return to smoother terrain. Thankfully, the effort wasn’t fruitless, as the rover was able to gather data on new spherule-rich rocks thought to have rolled downhill from “Midtoya,” including the witch hat or helmet-shaped rock “Horneflya,” which has attracted much online interest.
More recently, Perseverance explored a site called “Kerrlaguna” where the steep slopes give way to a field of megaripples: large windblown sand formations up to 1 meter (about 3 feet) tall. The science team chose to perform a mini-campaign to make a detailed study of these features. Why such interest? While often the rover’s attention is focused on studying processes in Mars’ distant past that are recorded in ancient rocks, we still have much to learn about the modern Martian environment.
Almost a decade ago, Perseverance’s forerunner Curiosity studied an active sand dune at “Namib Dune” on the floor of Gale crater, where it took a memorable selfie. However the smaller megaripples — and especially dusty, apparently no longer active ones like at “Kerrlaguna” — are also common across the surface of Mars. These older immobile features could teach us new insights about the role that wind and water play on the modern Martian surface.
After arriving near several of these inactive megaripples, Perseverance performed a series of measurements using its SuperCam, Mastcam-Z, and MEDA science instruments in order to characterize the surrounding environment, the size and chemistry of the sand grains, and any salty crusts that may have developed over time.
Besides furthering our understanding of the Martian environment, documenting these potential resources could help us prepare for the day when astronauts explore the Red Planet and need resources held within Martian soils to help them survive. It is hoped that this investigation at “Kerrlaguna” can provide a practice run for a more comprehensive campaign located at a more extensive field of larger bedforms at “Lac de Charmes,” further along the rover traverse.
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Explore This Section Earth Earth Observer Editor’s Corner Feature Articles Meeting Summaries News Science in the News Calendars In Memoriam Announcements More Archives Conference Schedules Style Guide 21 min read
A Decade of Global Water Cycle Monitoring: NASA Soil Moisture Active Passive Mission
Introduction
The NASA Soil Moisture Active Passive (SMAP) mission, launched in 2015, has over 10 years of global L-band radiometry observations. The low frequency [1.4 GHz frequency or 21 cm (8 in) wavelength] measurements provide information on the state of land surfaces in all weather conditions – regardless of solar illumination. A principal objective of the SMAP mission is to provide estimates of surface soil moisture and its frozen or thawed status. Over the land surface, soil moisture links the water, energy, and carbon cycles. These three cycles are the main drivers of regional climate and regulate the functioning of ecosystems.
The achievement of 10 years in orbit is a fitting time to reflect on what SMAP has accomplished. After briefly discussing the innovative measurement approach and the instrument payload (e.g., a radiometer and a regrettably short-lived L-band radar), a significant section of this article is devoted to describing the mission’s major scientific achievements and how the data from SMAP have been used to serve society (e.g., applied sciences) – including SMAP’s pathfinding role as Early Adopters. This content is followed by a discussion of how SMAP has dealt with issues related to radio frequency interference in the L-Band region, a discussion of the SMAP data products suite, future plans for the SMAP active–passive algorithm, and a possible follow-on L-band global radiometry mission being developed by the European Union’s Copernicus Programme that would allow for data continuity beyond SMAP. This summary for The Earth Observer is excerpted from a longer and more comprehensive paper that, as of this article’s posting, is being prepared for publication in the Proceedings of the Institute of Electrical and Electronics Engineers (IEEE).
SMAP Measurement Approach and Instruments
The SMAP primary and operating instrument is the L-band radiometer, which collects precise surface brightness temperature data. The radiometer includes advanced radio frequency interference (RFI) detection and mitigation hardware and software. The radiometer measures vertical and horizontal polarization observations along with the third and fourth Stokes parameters (T3 and T4) of the microwave radiation upwelling from the Earth. The reflector boom and assembly, which includes a 6 m (20 ft) deployable light mesh reflector, is spun at 14.6 revolutions-per-minute, which creates a 1000 km (621 mi) swath as the SMAP satellite makes its Sun-synchronous orbit of the Earth – see Figure 1. This approach allows coverage of the entire globe in two to three days with an eight-day exact repeat. The radiometer instrument is calibrated monthly by pointing it to the deep sky.
Figure 1. An artist’s rendering of the SMAP Observatory showing both the radiometer and radar. Figure credit: NASA/Jet Propulsion Laboratory/California Institute of Technology The original SMAP instrument design included a companion L-band radar, which operated from April through early July 2015, acquiring observations of co- and cross-polarized radar backscatter at a spatial resolution of about 1 km (0.6 mi) with a temporal revisit of about three days over land. This data collection revealed the dependence of L-band radar signals on soil moisture, vegetation water content, and freeze thaw state. The radar transmitter failed on July 7, 2015. Shortly thereafter, the radar receiver channels were repurposed to record the reflected signals from the Global Navigation Satellite System (GNSS) constellation in August 2015, making SMAP the first full-polarimetric GNSS reflectometer in space for the investigation of land surface and cryosphere.
Scientific Achievements from a Decade of SMAP Data
A decade of SMAP soil moisture observations have led to a plethora of scientific achievements. The data have been used to quantify the linkages of the three main metabolic cycles (e.g., carbon, water, and energy) on land. They have also been used to improve drought assessments and flood prediction as well as the accuracy of numerical weather prediction (NWP) models. They are also used to measure liquid water and thickness of ice sheets, and sea surface salinity. The subsections that follow describe how SMAP data are being put to use in myriad ways that benefit society.
Quantifying Processes that Link the Terrestrial Water, Energy, and Carbon Cycles
The primary SMAP science goal is to develop observational benchmarks of how the water, energy, and carbon cycles link together over land. Soil moisture is the variable state of the land branch of the water cycle. It links the water cycle to the energy cycle through limiting latent heat flux – the change in energy as heat exchanges when water undergoes a phase change, such as evapotranspiration at the land–atmosphere interface. Soil moisture also links the water and carbon cycles, which is evident through plant photosynthesis. SMAP global observations of soil moisture fields, in conjunction with remote sensing of elements of the energy and carbon cycles, can reveal how these three cycles are linked in the real world as a benchmark for weather and Earth system models.
Photosynthesis is down-regulated by both the deficit in water availability and the lack of an adequate amount of photosynthetically active radiation. Global maps reveal how soil moisture and light regulate photosynthesis – see Figure 2. These benchmark observational results can be used to assess how Earth system models link to the three main metabolic cycles of the climate system.
Figure 2. Observed regulation of photosynthesis by water availability [left] and light availability [right]. Blue denotes greater limitation. Photosynthesis rates for both maps determined using solar-induced fluorescence (SIF) measurements (mW/m2 nm sr) from the Tropospheric Ozone Monitoring Instrument (TROPOMI) on the European Union’s Copernicus Sentinel-5P mission. Water availability was determined using soil moisture (SM) measurements from the Soil Moisture Active Passive (SMAP) mission. Light availability was determined using measurements of photosynthetically active radiation (PAR) from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra and Aqua platforms. The resulting maps show the model slope (mW/m2/nm/sr) of the estimated SIF-SM relationship in the water-limited regime [left] and the model slope (10-3/nm/sr) of estimated SIF-PAR relationship in the light-limited regime [right]. Figure credit: Jonard et al (2022) in Biogeosciences Development of Improved Flood Prediction and Drought Monitoring Capability
SMAP products have also been widely used in applied sciences and natural hazard decision-support systems. SMAP’s observation-based soil moisture estimates offer transformative information for managing water-related natural hazards, such as monitoring agricultural drought – defined as a persistent deficit in soil moisture – and flood volumes – defined as the landscape’s water absorption capacity during precipitation events. The SMAP project produces a parallel, near-real-time data stream that is accessed by a number of federal and state agencies in decision-support systems related to drought monitoring, food security, and landscape inundation and trafficability.
Enhancing Weather and Climate Forecasting Skill
SMAP’s enhancement of numerical weather prediction, model skill, and reduction of climate model projection uncertainties is based on the premise of the contribution of solar energy to weather and climate dynamics. Soil moisture has a strong influence on how available solar energy is partitioned into components (e.g., sensible heat flux versus latent heat flux) over land. The influence propagates through the atmospheric boundary layer and ultimately influences the evolution of weather.
To give an example, land surface processes can affect the evolution of the U.S. Great Plains low-level jets (GPLLJs). These jets drive mesoscale convective weather systems. Previous studies have shown that GPLLJs are sensitive to regional soil moisture gradients. Assimilation of SMAP soil moisture data improves forecasts of weakly synoptically forced or uncoupled GPLLJs compared to forecasts of cyclone-induced coupled GPLLJs. For example, the NASA Unified Weather Research and Forecasting Model, with 75 GPLLJs at 9 km (5.6 mi) resolution both with and without SMAP soil moisture data assimilation [SMAP data assimilation (DA) and no-DA respectively], shows how the windspeed mean absolute difference between SMAP DA and no-DA increase approximately linearly over the course of the simulation with maximum differences at 850 hPa (or mb) for the jet entrance and core – see Figure 3.
Figure 3. The impact of adding soil moisture data [SMAP data assimilation (DA) minus no-DA] to a model simulation from theNASA Unified Weather Research and Forecasting Model (NU-WRF)) of the Great Plains Low Level Jet (GPLLJ). The results show the mean over 75 independent GPLLJ events. The plots correspond to wind speed difference with height (y-axis) and time (hours on x-axis). The panels are for jet entrance [left], jet core [middle] and jet exit [right]. Soil moisture data assimilation enhances the intensity of the simulated GPLLJ. The stippling corresponds to 99% statistical confidence. Figure credit: Ferguson (2020) in Monthly Weather Review Measuring Liquid Water Content and Thickness of Ice Sheets
The mass loss of Greenland and Antarctica ice sheets contributes to sea-level rise – which is one of the most impactful and immediate damaging consequences of climate change. The melt rates over the last few years have raised alarm across the globe and impact countries with coastal communities. The cryosphere community has raised a call-to-action to use every observing system and model available to monitor the patterns and rates of land ice melt.
Surface melt affects the ice cap mass loss in many ways: the direct melt outflow from the ablation zone of the Greenland ice sheet, the structural change of the percolation zone of the Greenland ice sheet, changes in the melt water retention and outflow boundaries, changes in the structure of the Antarctic ice shelves, and destabilization of the buttressing of the glacier outflow through various processes (e.g., hydrofracturing and calving). The long-term climate and mass balance models rely on accurate representation of snow, firn, and ice processes to project the future sea level.
The SMAP L-band radiometer has relatively long wavelength [21 cm (8 in)] observations compared to other Earth-observing instruments. It enables the measurement of liquid water content (LWC) in the ice sheets and shelves as it receives the radiation from the deep layers of the snow/firn/ice column. Relatively high LWC values absorb the emission only partially, making the measurement sensitive to different liquid water amounts (LWA) in the entire column. Figure 4 shows the cumulative LWA for 2015–2023 based on SMAP measurements.
Figure 4. Total annual sum of SMAP daily liquid water amount (LWA) for 2015–2023. The black solid line on each map represents grid edges, and the grey color mask inside the ice sheet indicates melt detections by decreasing brightness temperature. Figure Credit: Andreas Colliander [Finnish Meteorological Institute]. The SMAP L-band radiometer has also been used to derive the thickness of thin sea ice [Soil Moisture and Ocean Salinity (SMOS) mission have been recalibrated to SMAP, using the same fixed incidence angle. The data show strong agreement and demonstrate clear benefits of a combined dataset. The L-band thin ice thickness retrievals provide a useful complement to higher-resolution profiles of thicker ice obtained from satellite altimeters (e.g. ESA’s CryoSat-2 and NASA’s Ice, Clouds and land Elevation Satellite–2 missions).
Extending and Expanding the Aquarius Sea Surface Salinity Record
The joint NASA/Argentinian Aquarius/Satélite de Aplicaciones Científicas (SAC)-D (Aquarius), which operated from 2011–2015, used an L-band radiometer and an L-band scatterometer to make unprecedented monthly maps of global sea surface salinity at 150-km (93-mi) resolution. The SMAP L-band radiometer has not only extended the sea surface salinity record in the post-Aquarius period, it has also increased the spatial resolution and temporal frequency of these measurements because of its larger reflector and wider swath. The increased resolution and revisit allow new and unprecedented perspectives into mixing and freshwater events, coastal plume tracking, and other more local oceanic features.
Providing New Perspectives on Global Ecology and Plant Water Stress
The L-band vegetation optical depth (VOD) – which is related to water content in vegetation – has been retrieved simultaneously with soil moisture using SMAP’s dual-polarized brightness temperatures and is being used to better understand global ecology. Water in above-ground vegetative tissue attenuates and thus depolarizes surface microwave emission, and VOD quantifies this effect. SMAP can provide global observations of VOD in all weather conditions with a two to three day temporal frequency. Changes in VOD indicate either plant rehydration or growth. Ecologists benefit from this new ecosystem observational data, which augments optical and near-infrared vegetation indices [e.g., leaf area index (LAI)] and has a higher temporal frequency that is not affected by clouds and does not saturate as rapidly for dense vegetation.
Examples of how the data have been used include deciphering the conditions when vegetation uptakes soil water only for rehydration (i.e., VOD increase with no LAI change) compared to plant growth (i.e., increase in both VOD and LAI). The applications of VOD are increasing and the ecology community views this product as a valuable additional perspective on soil–plant water relations.
At the moment, this measurement has no ground-based equivalent. Therefore, field experiments with airborne instruments and ground sampling teams are needed to firmly establish the product as a new observational capability for global ecology.
Applied Science Collaboration: SMAP Observations Serving Society
The SMAP project has worked with the NASA Earth Science Division Applied Sciences Program (now known as Earth Science to Action) and the natural hazards monitoring and forecasting communities for pre- and post-launch implementation of SMAP products in their operations. In some operational applications, for which long-term data continuity is a requirement, the SMAP data are still used for assessment of current conditions, as well as research and development.
The Original Early Adopters
Prior to its launch, the SMAP mission established a program to explore and facilitate applied and operational uses of SMAP mission data products in decision-making activities for societal benefit. To help accomplish these objectives, SMAP was the first NASA mission to create a formal Applications Program and an Early Adopter (EA) program, which eventually became a requirement for all future NASA Earth Science directed satellite missions. SMAP’s EA program increases the awareness of mission products, broadens the user community, increases collaboration with potential users, improves knowledge of SMAP data product capabilities, and expedites the distribution and uses of mission products after launch.
SMAP Data in Action
Several project accomplishments have been achieved primarily through an active continuous engagement with EAs and operational agencies working towards national interests. SMAP soil moisture data have been used by the U.S. Department of Agriculture (USDA) for domestic and international crop yield applications. For example the USDA’s National Agricultural Statistics Service (NASS) conducts a weekly survey of crop progress, crop condition, and soil moisture condition for U.S. cropland. NASS surveys and publishes state-level soil moisture conditions in the NASS Crop Progress Report.
The traditional field soil moisture survey is a large-scale, labor-intensive data collection effort that relies heavily on responses from farmers, agricultural extension agents and/or other domain experts for field observations. One weakness of these observations is that they are based on subjective assessments rather than quantitative measures and can lead to spatial inconsistency based on the human responses from the respective counties. Moreover, the NASS Crop Progress Reports do not provide specific geolocation information for the assessed soil moisture conditions – which are extremely useful metadata to provide to data users. NASS implemented the use of SMAP observations in their weekly reports during the growing period (March–November). SMAP maps estimated root-zone soil moisture for the week of November 14–20, 2022, over NASS Pacific (California and Nevada) and Delta (Arkansas, Mississippi and Louisiana) regional domains—see Figure 5.
Figure 5. SMAP-based soil moisture estimates for California, Nevada, Arkansas, Mississippi, and Louisiana, used by the U.S. Department of Agriculture’s (USDA) National Agricultural Statistics Service (NASS) in their weekly report covering November 14–20, 2022. These data are available for selected states at the NASS website linked in the text. Figure Credit: NASS SMAP Radio Frequency Interference Detection and Mitigation
Although SMAP operates within the protected frequency allocation of 1400–1427 MHz, the radiometer has been impacted by radio frequency interference over the mission lifetime. Unauthorized in-band transmitters as well as out-of-band emissions from transmitters operating adjacent to the allocated spectrum have been observed in SMAP measurements since its launch. The previously launched SMOS and Aquarius radiometers provide evidence of global RFI at L-band. Consequently, SMAP was designed to incorporate a novel onboard digital detector on the back end to enable detection and filtering of RFI. The radiometer produces science data in time and frequency, enabling the use of multiple RFI detection methods in the ground processing software.
On-orbit data demonstrate that the RFI detection and filtering performs well and improves the quality of SMAP brightness temperature measurements. The algorithms are most effective at filtering RFI that is sparse in time and frequency, with minimal impact on the noise equivalent delta temperature (NEDT) – a measure of the radiometer sensitivity. Some areas of the globe remain problematic as RFI that is very high level and persistent results in high percentages of data loss due to removal of contaminated data. A global map of RFI detection rate for January 2025 shows a large contrast between Eastern and Western Hemispheres and between Northern and Southern Hemispheres – see Figure 6. Regions of isolated RFI and severe RFI correspond to populated areas. A detection rate of 100% means all pixels are flagged and removed, resulting in data loss. Analysis of spectral information reveal many sources are likely terrestrial radar systems; however, many wideband, high-level sources and low-level, non-radar sources also persist. Over areas of geopolitical conflict, the time-frequency data show interference covering the entire radiometer receiver bandwidth.
Figure 6. Percentage of pixels on a 0.25° grid for January 2025 that have been flagged for removal by the Soil Moisture Active Passive radio frequency interference detection algorithms. Figure Credit: Priscilla N. Mohammed [GSFC] The RFI challenge is further addressed through official spectrum management channels and formal reports that include the geolocated coordinates of sources, interference levels, frequency of occurrence during the observed period, and spectral information – all of which aid field agents as they work to identify potential offenders. Reports are submitted to the NASA Spectrum office and then forwarded to the country of interest through the Satellite Interference Reporting and Resolution System.
SMAP Science Data Products
The current suite of SMAP science data products is available in the Table. The principal data products are grouped in four levels designated as L1–4. The L1 products are instrument L-band brightness temperature in Kelvin and include all four Stokes parameters (i.e., horizonal and vertical polarization as well as third and fourth Stokes). Both 6:00 AM equatorial crossing (descending) and 6:00 PM equatorial crossing (ascending data) are contained in the products. The user has access to quality flags of the conditions under which measurements are available for each project. The L1B products are time-ordered and include fore and aft measurements. L1C products are on the Equal-Area Scalable Earth V2 (EASE2) grid with polar and global projections. L2 data products are geophysical retrievals (i.e., soil moisture, VOD, and binary freeze/thaw classification on a fixed Earth grid). The L2 half-orbit products are available to the public within a day of acquisition. L3 products are daily composites and include all half-orbits for that day.
The SMAP project also produces L4 data that are the result of data assimilation. The L4 products take advantage of other environmental observations, such as precipitation, air temperature and humidity, radiative fluxes at the land surface, and ancillary land use and soil texture information, to produce estimates of surface [nominally 0–5 cm (0–2 in)] and subsurface (e.g., root-zone up to a meter) soil moisture. The data assimilation system is a merger of model and measurements and hence resolves the diurnal cycle of land surface conditions. The data assimilation system also provides estimates of surface fluxes of carbon, energy, and water, such as evaporation, runoff, gross primary productivity (GPP), and respiration. The difference between GPP and respiration is the net ecosystem exchange, which is the net source/sink of the carbon cycle over land.
The SMAP suite of products also include near-real-time (NRT) brightness temperature and soil moisture products for use in operational weather forecast applications. The NRT product targets delivery to users within three hours of measurement acquisition. The NRT uses predicted SMAP antenna pointing (instead of telemetry) and model predicted ancillary data (soil temperature) in order to support operational centers that require more than three hours of data products for updating weather forecast models. To date SMAP has met its required and target (for NRT) latency requirements.
Two other data projects merge synergistically with other (colocated) satellite measurements. The SPL2SMAP_S merges SMAP L-band radio brightness measurements with C-band synthetic aperture radar (SAR) measurements from the ESA Copernicus Sentinel-1 mission. The SAR data have high resolution and allow the generation of 1 and 3 km (0.62 and 1.8 mi) merged surface soil moisture estimates. The high resolution soil moisture information, however, is only available when there is coincident SMAP and Sentinel-1 measurements. The refresh rate of this product is limited and can be as long as 12 days.
The merged SMOS–SMAP passive L-band radiometry data allows the generation of global, near daily surface soil moisture estimates, which are required to resolve fast hydrologic processes, such as gravity drainage and recharge flux. These parameters are only partially resolved with the SMAP, with a two to three day data refresh rate. This product interpolates the multi-angular SMOS data to the SMAP 40º incident angle and uses all SMAP algorithms, including correction of waterbody impact on SMAP brightness temperature, and ancillary data for geophysical inversions to soil moisture and VOD, ensuring consistency. The combined SMAP–SMOS data product may not be available daily across locations, such as Japan, parts of China, and the Middle East, where RFI affects data collection.
Table. Soil Moisture Active Passive suite of science products are available through the National Snow and Ice Data Center, one of NASA’s Distributed Active Archive Centers.
Product Type Product description Resolution (Gridding) Granule Extent SPL1BTB Geolocated, calibrated brightness temperature in time order 36 km Half Orbit SPL1CTB_E Backus-Gilbert interpolated, calibrated brightness temperature in time order (9 km) Half Orbit SPL1CTB Geolocated, calibrated brightness temperature on Equal-Area Scalable Earth V2 (EASE2) grid 36 km Half Orbit SPL1CTB_E Backus-Gilbert interpolated, calibrated brightness temperature on EASE2 grid (9 km) Half Orbit SPL2SMP Radiometer soil moisture and vegetation optical depth 36 km Half Orbit SPL2SMP_E Radiometer soil moisture and vegetation optical depth based on SPL1CTB (9 km) Half Orbit SPL2SMAP_S SMAP radiometer/Copernicus Sentinel-1 soil moisture 3 km Sentinel-1 SPL3SMP Daily global composite radiometer soil moisture and vegetation optical depth based on SPL1CTB 36 km Daily–Global SPL3SMP_E Daily global composite radiometer soil moisture and vegetation optical depth based on SPL1CTB_E (9 km) Daily–Global SPL3FTP Daily composite freeze/thaw state based on SPL1CTB 36 km Daily–Global SPL3FTP_E Daily composite freeze/thaw state based on SPL1CTB_E (9 km) Daily–Global SPL4SMAU Surface and Root Zone soil moisture 9 km 3 hours – Global SPL4CMDL Carbon Net Ecosystem Exchange 9 km Daily–Global SPL1BTB_NRT Near Real Time Geolocated, calibrated brightness temperature in time order 36 km Half Orbit SPL2SMP_NRT Near Real Time Radiometer soil moisture 36 km Half Orbit L2/L3 SMOS SM SMOS soil moisture and VOD based on SMAP algorithms (9 km) Half Orbit/Daily Global Future Directions for the SMAP Active–Passive Algorithm
Although the SMAP radar failed not long after launch, the data that were collected have been used to advance the development of the SMAP Active–Passive (AP) algorithm, which will be applied to the combined SMAP radiometer data and radar data from the NASA–Indian Space Research Organisation (ISRO) Synthetic Aperture Radar [NISAR] mission, a recently-launched L-Band Synthetic Aperture mission to produce global soil moisture at a spatial resolution of 1 km (0.62 mi) or better. The high resolution product can advance applications of SMAP data (e.g., agricultural productivity, wildfire, and landslide monitoring).
Data Continuity Beyond SMAP
A forthcoming mission meets some – but not all – of the SMAP measurement requirements and desired enhancements. The European Union’s Copernicus Program Copernicus Imaging Microwave Radiometer (CIMR) mission is a proposed multichannel microwave radiometry observatory that includes L-band and four other microwave channels sharing a large mesh reflector. The mesh reflector is similar to the one that is used on SMAP, but larger. The successful SMAP demonstration of rotating large deployable mesh antennas for Earth observations has been useful to the CIMR design.
In terms of RFI detection capability, CIMR will also use an approach that is similar to SMAP. With regard to instrument thermal noise (NEDT) and data latency, CIMR meets or comes close to the next-mission desired characteristics and equals or exceeds SMAP in most of the attributes. The native L-band resolution of CIMR is ~60 km (37 mi); however, the measurements are coincident and higher-resolution measurements in this configuration allow reconstruction of L-band radiometry at higher resolution than CIMR’s L-band. It may be possible to combine the L- and C-bands and achieve a reconstructed ~15 km (9 mi) L-band product based on the coincident and overlapping measurements. A refresh rate of one day is possible with the wide-swath characteristic of CIMR.
CIMR is currently in development; the first version, CIMR-1A, is expected to launch within this decade and the second version, CIMR-1B, in the mid 2030s. Since the Copernicus program supports operational activities (e.g., numerical weather prediction), the program includes plans for follow-on CIMR observatories so that the data record will be maintained without gaps in the future.
Conclusions
The SMAP mission was launched in 2015 and has produced over 10 years of science data. Because of its unique instrument and operating characteristics, the global low-frequency microwave radiometry with the SMAP observatory has resulted in surface soil moisture, vegetation optical depth, and freeze/thaw state estimates that outperform past and current products. The data have been widely used in the Earth system science community and also applied to natural hazards applications.
The Earth system science and application communities are actively using the decade-long, high-quality global L-band radiometry. The intensity and range of SMAP science data usage is evident in the number of peer-reviewed journal publications that contain SMAP or Soil Moisture Active Passive in their title or abstract and use SMAP data in the study (i.e., search: www.webofscience.com data-base). The authors acknowledge that many publications escape this particular query approach. Currently the bibliography includes over 1700 entries and over 20,000 citations spanning several elements of Earth system science, including hydrologic science and regional and global water cycle, oceanic and atmospheric sciences, cryosphere science, global ecology as well as microwave remote sensing technologies.
To Learn More About SMAP
A more comprehensive bibliography of studies published based on SMAP data products, a set of one-page SMAP science and applications highlights in standardized format, and SMAP project documents including assessment reports are all available online via the links provided.
Acknowledgements
The authors wish to acknowledge the contributions of the SMAP Science Team, the SMAP Algorithm Development Team, and the SMAP Project Office engineers and staff. All of these teams contribute to the ongoing SMAP science product generation and uses reported in this article.
Dara Entekhabi
Massachusetts Institute of Technology
darae@mit.edu
Simon Yueh
Jet Propulsion Laboratory/California Institute of Technology
simon.h.yueh@jpl.nasa.gov
Rajat Bindlish
NASA Goddard Space Flight Center
rajat.bindlish@nasa.gov
Mark Garcia
Jet Propulsion Laboratory/California Institute of Technology
mark.d.garcia@jpl.nasa.gov
Jared Entin
NASA Headquarters
jared.k.entin@nasa.gov
Craig Ferguson
NASA Headquarters
craig.r.ferguson@nasa.gov
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Last Updated Aug 18, 2025 Related Terms
Earth Science View the full article
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By NASA
5 min read
How NASA’s SPHEREx Mission Will Share Its All-Sky Map With the World
NASA’s SPHEREx mission will map the entire sky in 102 different wavelengths, or colors, of infrared light. This image of the Vela Molecular Ridge was captured by SPHEREx and is part of the mission’s first ever public data release. The yellow patch on the right side of the image is a cloud of interstellar gas and dust that glows in some infrared colors due to radiation from nearby stars. NASA/JPL-Caltech NASA’s newest astrophysics space telescope launched in March on a mission to create an all-sky map of the universe. Now settled into low-Earth orbit, SPHEREx (Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer) has begun delivering its sky survey data to a public archive on a weekly basis, allowing anyone to use the data to probe the secrets of the cosmos.
“Because we’re looking at everything in the whole sky, almost every area of astronomy can be addressed by SPHEREx data,” said Rachel Akeson, the lead for the SPHEREx Science Data Center at IPAC. IPAC is a science and data center for astrophysics and planetary science at Caltech in Pasadena, California.
Almost every area of astronomy can be addressed by SPHEREx data.
Rachel Akeson
SPHEREx Science Data Center Lead
Other missions, like NASA’s now-retired WISE (Wide-field Infrared Survey Explorer), have also mapped the entire sky. SPHEREx builds on this legacy by observing in 102 infrared wavelengths, compared to WISE’s four wavelength bands.
By putting the many wavelength bands of SPHEREx data together, scientists can identify the signatures of specific molecules with a technique known as spectroscopy. The mission’s science team will use this method to study the distribution of frozen water and organic molecules — the “building blocks of life” — in the Milky Way.
This animation shows how NASA’s SPHEREx observatory will map the entire sky — a process it will complete four times over its two-year mission. The telescope will observe every point in the sky in 102 different infrared wavelengths, more than any other all-sky survey. SPHEREx’s openly available data will enable a wide variety of astronomical studies. Credit: NASA/JPL-Caltech The SPHEREx science team will also use the mission’s data to study the physics that drove the universe’s expansion following the big bang, and to measure the amount of light emitted by all the galaxies in the universe over time. Releasing SPHEREx data in a public archive encourages far more astronomical studies than the team could do on their own.
“By making the data public, we enable the whole astronomy community to use SPHEREx data to work on all these other areas of science,” Akeson said.
NASA is committed to the sharing of scientific data, promoting transparency and efficiency in scientific research. In line with this commitment, data from SPHEREx appears in the public archive within 60 days after the telescope collects each observation. The short delay allows the SPHEREx team to process the raw data to remove or flag artifacts, account for detector effects, and align the images to the correct astronomical coordinates.
The team publishes the procedures they used to process the data alongside the actual data products. “We want enough information in those files that people can do their own research,” Akeson said.
One of the early test images captured by NASA’s SPHEREx mission in April 2025. This image shows a section of sky in one infrared wavelength, or color, that is invisible to the human eye but is represented here in a visible color. This particular wavelength (3.29 microns) reveals a cloud of dust made of a molecule similar to soot or smoke. NASA/JPL-Caltech This image from NASA’s SPHEREx shows the same region of space in a different infrared wavelength (0.98 microns), once again represented by a color that is visible to the human eye. The dust cloud has vanished because the molecules that make up the dust — polycyclic aromatic hydrocarbons — do not radiate light in this color. NASA/JPL-Caltech
During its two-year prime mission, SPHEREx will survey the entire sky twice a year, creating four all-sky maps. After the mission reaches the one-year mark, the team plans to release a map of the whole sky at all 102 wavelengths.
In addition to the science enabled by SPHEREx itself, the telescope unlocks an even greater range of astronomical studies when paired with other missions. Data from SPHEREx can be used to identify interesting targets for further study by NASA’s James Webb Space Telescope, refine exoplanet parameters collected from NASA’s TESS (Transiting Exoplanet Survey Satellite), and study the properties of dark matter and dark energy along with ESA’s (European Space Agency’s) Euclid mission and NASA’s upcoming Nancy Grace Roman Space Telescope.
The SPHEREx mission’s all-sky survey will complement data from other NASA space telescopes. SPHEREx is illustrated second from the right. The other telescope illustrations are, from left to right: the Hubble Space Telescope, the retired Spitzer Space Telescope, the retired WISE/NEOWISE mission, the James Webb Space Telescope, and the upcoming Nancy Grace Roman Space Telescope. NASA/JPL-Caltech The IPAC archive that hosts SPHEREx data, IRSA (NASA/IPAC Infrared Science Archive), also hosts pointed observations and all-sky maps at a variety of wavelengths from previous missions. The large amount of data available through IRSA gives users a comprehensive view of the astronomical objects they want to study.
“SPHEREx is part of the entire legacy of NASA space surveys,” said IRSA Science Lead Vandana Desai. “People are going to use the data in all kinds of ways that we can’t imagine.”
NASA’s Office of the Chief Science Data Officer leads open science efforts for the agency. Public sharing of scientific data, tools, research, and software maximizes the impact of NASA’s science missions. To learn more about NASA’s commitment to transparency and reproducibility of scientific research, visit science.nasa.gov/open-science. To get more stories about the impact of NASA’s science data delivered directly to your inbox, sign up for the NASA Open Science newsletter.
By Lauren Leese
Web Content Strategist for the Office of the Chief Science Data Officer
More About SPHEREx
The SPHEREx mission is managed by NASA’s Jet Propulsion Laboratory for the agency’s Astrophysics Division within the Science Mission Directorate at NASA Headquarters. BAE Systems in Boulder, Colorado, built the telescope and the spacecraft bus. The science analysis of the SPHEREx data will be conducted by a team of scientists located at 10 institutions in the U.S., two in South Korea, and one in Taiwan. Caltech in Pasadena managed and integrated the instrument. The mission’s principal investigator is based at Caltech with a joint JPL appointment. Data will be processed and archived at IPAC at Caltech. The SPHEREx dataset will be publicly available at the NASA-IPAC Infrared Science Archive. Caltech manages JPL for NASA.
To learn more about SPHEREx, visit:
https://nasa.gov/SPHEREx
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Last Updated Jul 02, 2025 Related Terms
Open Science Astrophysics Galaxies Jet Propulsion Laboratory SPHEREx (Spectro-Photometer for the History of the Universe and Ices Explorer) The Search for Life The Universe Explore More
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