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Summary of the 10th DSCOVR EPIC and NISTAR Science Team Meeting


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Summary of the 10th DSCOVR EPIC and NISTAR Science Team Meeting

Introduction

The 10th Deep Space Climate Observatory (DSCOVR) Earth Polychromatic Camera (EPIC) and National Institute of Standards and Technology (NIST) Advanced Radiometer [NISTAR] Science Team Meeting (STM) was held October 16–18, 2024. Over 50 scientists attended, most of whom were from NASA’s Goddard Space Flight Center (GSFC), with several participating from other NASA centers, U.S. universities, and U.S. Department of Energy laboratories. There was one international participant – from Estonia. A full overview of DSCOVR’s Earth-observing instruments was published in a previous article in The Earth Observer and will not be repeated here. This article provides the highlights of the 2024 meeting. The meeting agenda and full presentations can be downloaded from GSFC’s Aura Validation Data Center.

Opening Presentations

The opening session of the 10th DSCOVR STM was special. Former U.S., Vice President Al Gore attended the opening session and gave a presentation at the panel discussion “Remote Sensing and the Future of Earth Observations” – see Photo. Gore was involved in the early days of planning the DSCOVR mission, which at that time was known as Triana. He reminisced about his involvement and praised the team for the work they’ve done over the past decade to launch and maintain the DSCOVR mission. Following the STM Opening Session, Gore spoke at a GSFC Engage session in Building 3 later that afternoon on the same topic, but before a wider audience. [Link forthcoming.]

Following Gore’s remarks, the remainder of the opening session consisted of a series of presentations from DSCOVR mission leaders and representatives from GSFC and National Oceanic and Atmospheric Administration (NOAA). Thomas Neumann [GSFC, Earth Sciences Division (ESD)—Deputy Director] opened the meeting and welcomed Vice President Gore and the STM participants on behalf of the ESD. Adam Szabo [GSFC—DSCOVR Project Scientist] briefly reported that the spacecraft was still in “good health.” The EPIC and NISTAR instruments on DSCOVR continue to return their full science observations. He also gave an update on DSCOVR Space Weather research. Alexander Marshak [GSFC—DSCOVR Deputy Project Scientist] briefly described DSCOVR mission history and the science results based on DSCOVR observations from the first Sun–Earth Lagrange point (hereinafter, the L1 point). He also summarized the major EPIC and NISTAR results to date. At this time, more than 125 papers related to DSCOVR are listed on the EPIC website. Elsayed Talaat [NOAA, Office of Space Weather observations—Director] discussed the future of Earth and space science studies from the L1 point.

DSCOVR photo
Photo. Former U.S. Vice President Al Gore spoke at the opening session of the 10th DSCOVR Science Team Meeting. This photo shows Gore together with Makenzie Lystrup [NASA’s Goddard Space Flight Center (GSFC)—Center Director], Christa Peters-Lidard [GSFC, Director of the Science and Exploration Directorate], Elsayed Talaat [National Oceanic and Atmospheric Administration (NOAA)—Director of the Office of Space Weather Observations], Dalia Kirschbaum [GSFC—Director of Earth Sciences], other GSFC management, and members of the DSCOVR Science Team.
Photo credit: Katy Comber (GSFC)

Updates on DSCOVR Operations

The DSCOVR mission components continue to function nominally. The meeting was an opportunity to update participants on progress over the past year on several fronts, including data acquisition, processing, and archiving, and release of new versions of several data products. The number of people using DSCOVR data continues to increase, with a new Science Outreach Team having been put in place to aid users in several aspects of data discovery, access, and user friendliness.

Amanda Raab [NOAA, DSCOVR Mission Operations and Systems] reported on the current status of the DSCOVR mission. She also discussed spacecraft risks and issues such as memory fragmentation and data storage task anomalies but indicated that both these issues have been resolved.

Hazem Mahmoud [NASA’s Langley Research Center (LaRC)] discussed the work of the Atmospheric Science Data Center (ASDC), which is based at LaRC. He showed DSCOVR mission metrics since 2015, focusing on data downloads and the global outreach of the mission. He noted that there has been a significant rise in the number of downloads and an increasing diversity of countries accessing ozone (O3), aerosol, and cloud data products. Mahmoud also announced that the ASDC is transitioning to the Amazon Web Services cloud, which will further enhance global access and streamline DSCOVR data processing.

Karin Blank [GSFC] covered the discovery of a new type of mirage that can only be seen in deep space from EPIC. The discussion included the use of a ray tracer in determining the origin of the phenomenon, and under what conditions it can be seen.

Alexander Cede [SciGlob] and Ragi Rajagopalan [LiftBlick OG] gave an overview of the stability of the EPIC Level-1A (L1A) data over the first decade of operation. They explained that the only observable changes in the EPIC calibration are to the dark count and flat field can – and that these changes can be entirely attributed to the temperature change of the system in orbit compared to prelaunch conditions. No additional hot or warm pixels have emerged since launch and no significant sensitivity drifts have been observed. The results that Cede and Rajagopalan showed that EPIC continues to be a remarkably stable instrument, which is attributed to a large extent to its orbit around the L1 point, which is located outside the Earth’s radiation belts and thus an extremely stable temperature environment. Consequently, in terms of stability, the L1 point is far superior to other Earth observation points, e.g., ground-based, low-Earth orbit (LEO), polar orbit, or geostationary Earth orbit (GEO).

Marshall Sutton [GSFC] discussed the state of the DSCOVR Science Operation Center (DSOC). He also talked about processing EPIC Level-1 (L1) data into L2 science products, daily images available on the EPIC website, and special imaging opportunities, e.g., volcanic eruptions.

EPIC Calibration

After 10 years of operation in space, the EPIC instrument on DSCOVR continues to be a remarkably stable instrument. The three presentations describe different ways that are used to verify the EPIC measurements remain reliable.

Conor Haney [LaRC] reported on anomalous outliers during February and March 2023 from the broadband shortwave (SW) flux using EPIC L1B channel radiances. To ensure that these outliers were not a result of fluctuations in the EPIC L1B channel radiances, both the EPIC radiance measurements and coincident, ray-matched radiance measurements from the Visible Infrared Imaging Radiometer Suite (VIIRS), on the Suomi National Polar-orbiting Partnership (Suomi NPP) platform, were processed using the same deep convective cloud invariant target (DCC-IT) algorithm. This analysis confirmed that the anomalous behavior was due to the DCC-IT algorithm – and not because of fluctuations in the EPIC L1B channel radiances. The improved DCC-IT methodology was also applied to the EPIC L1B radiances. The results indicate that the EPIC record is quite stable with a lower uncertainty than when processed using the previous DCC-IT methodology.

Igor Geogdzhaev [NASA’s Goddard Institute for Space Studies (GISS)/Columbia University] reported that EPIC Visible–Near Infrared (VIS-NIR) calibration based on VIIRS (on Suomi NPP) data has showed excellent stability, while VIIRS (on NOAA-20 and -21) derived gains agree to within 1–2%. Preliminary analysis showed continuity in the gains derived from Advanced Baseline Imager (ABI) data. (ABI flies on NOAA’s two operational Geostationary Operational Environmental Satellite–Series R satellites – GOES-17 and GOES-18.

Liang–Kang Huang [Science Systems and Applications, Inc. (SSAI)] reported on updates to the EPIC ultraviolet (UV) channel sensitivity time dependences using Sun-normalized radiance comparisons between EPIC and measurements from the Ozone Mapping and Profiler Suite (OMPS) Nadir Mapper (NM) on Suomi NPP, with coinciding footprints and solar/satellite angles. Huang’s team determined vignetting factors in the sensitivity calibration between 2021–2024, as a function of charge coupled device (CCD) pixel radius and pixel polar angles, using special lunar measurement sequences.

NISTAR Status and Science with Its Observations

The NISTAR instrument remains fully functional and continues its uninterrupted data record. The NISTAR-related presentations during this meeting included more details on specific topics related to NISTAR as well as on efforts to combine information from both EPIC and NISTAR.

Steven Lorentz [L-1 Standards and Technology, Inc.] reported that the NISTAR on DSCOVR has been measuring the irradiance from the sunlit Earth in three bands for more than nine years. The three bands measure the outgoing total and reflected-solar radiation from Earth at a limited range of solar angles. To compare the long-term stability of EPIC and NISTAR responses, researchers developed a narrowband to wideband conversion model to allow the direct comparison of the EPIC multiband imagery and NISTAR SW – see Figure 1 – and silicon photodiode channels. Lorentz presented daily results spanning several years. The comparison employed different detectors from the same spacecraft – but with the same vantage point – thereby avoiding any model dependent orbital artifacts.

DSCOVR Figure 1
Figure 1. NISTAR daily average shortwave (SW) radiance plotted for each year from 2017–2024. The results indicated a 10% increase in the shortwave radiance as the backscattering angle approaches 178° in December 2020. A 6% increase is noted in September of the same year.
Figure credit: Steven Lorentz (L-1 Standards and Technology)

Clark Weaver [University of Maryland, College Park (UMD)] used spectral information from the SCanning Imaging Absorption spectroMeter for Atmospheric CartograpHY (SCIAMACHY), which flew on the European Space Agency’s (ESA) Envisat satellite from 2002–2012, to fill EPIC spectral gaps. He reported on construction of a composite height resolution spectrum that was spectrally integrated to produce SW energy. Weaver explained that he compared the EPIC reflected SW with four-hour averages from Band 4 on NISTAR. He used spectral information from SCIAMACHY to fill in gaps. Weaver also discussed results of a comparison of area integrated EPIC SW energy with observations from NISTAR . 

Andrew Lacis [GISS] reported on results of analysis of seven years of EPIC-derived planetary albedo for Earth, which reveal global-scale longitudinal variability occurring over a wide range of frequencies – with strong correlation between nearby longitudes and strong anticorrelation between diametrically opposed longitudes. This behavior in the Earth’s global-scale energy budget variability is fully corroborated by seven years of NISTAR silicon photodiode measurements, which view the Earth with 1º longitudinal resolution. This analysis establishes the DSCOVR mission EPIC/NISTAR measurements as a new and unmatched observational data source for evaluating global climate model performance– e.g., see Figure 2.

DSCOVR Figure 2
Figure 2. This graph shows the diurnal variation in planetary albedo as measured by EPIC for five different eight-day-Blurred Meridians relative to Global Mean for 2021 [left] and 2022 [right].
Figure credit: Andrew Lacis [GISS]

Wenying Su [LaRC] discussed global daytime mean SW fluxes within the EPIC field of view produced from January 2016–June 2024. These quasi-hourly SW fluxes agree very well with the Synoptic data product from the Clouds and the Earth’s Radiant Energy System (CERES) instruments (currently flying on the Terra and Aqua, Suomi NPP, and NOAA-20 platforms) with the root mean square errors (rmse) less than 3 W/m2. This SW flux processing framework will be used to calculate NISTAR SW flux when Version 4 (V4) of the NISTAR radiance becomes available. Su noted that SW fluxes from EPIC are not suitable to study interannual variability as the magnitude of EPIC flux is sensitive to the percentage of daytime area visible to EPIC.

Update on EPIC Products and Science Results

EPIC has a suite of data products available. The following subsections summarize content during the DSCOVR STM related to these products. The updates focus on several data products and the related algorithm improvements. 

Total Column Ozone

Jerry Ziemke [Morgan State University (MSU), Goddard Earth Sciences Technology and Research–II (GESTAR II)] and Natalya Kramarova [GSFC] reported that tropospheric O3 from DSCOVR EPIC shows anomalous reductions of ~10% throughout the Northern Hemisphere (NH) starting in Spring 2020 that continues to the present. The EPIC data, along with other satellite-based (e.g., Ozone Monitoring Instrument (OMI) on NASA’s Aura platform) and ground-based (e.g., Pandora) data, indicate that the observed NH reductions in O3 are due to combined effects from meteorology and reduced pollution, including reduced shipping pollution in early 2020 (during COVID) – see Figure 3. EPIC 1–2 hourly data are also used to evaluate hourly total O3 and derived tropospheric O3 from NASA’s Tropospheric Emissions: Monitoring of Pollution (TEMPO) geostationary instrument. Ziemke explained that comparison of TEMPO data with EPIC data has helped the researchers characterize a persistent latitude-dependent offset in TEMPO total O3 data of ~10–15% from south to north over the North American continent.

DSCOVR Figure 3
Figure 3. This dataset combines input from EPIC, OMPS, and OMI from 2004–2022. The onset of the COVID-19 pandemic in 2020 can be seen clearly in the data as it corresponds to a sudden drop in tropospheric column ozone by ~3 Dobson Units in the Northern Hemisphere.
Figure credit: Jerry Ziemke (Morgan State University, GESTAR-II)

Algorithm Improvement for Ozone and Sulfur Dioxide Products

Kai Yang [UMD] presented a comprehensive evaluation of total and tropospheric O3 retrievals, highlighting the long-term stability and high accuracy of EPIC measurements. He also validated EPIC’s volcanic sulfur dioxide (SO2) retrievals by comparing them with ground-based Brewer spectrophotometer measurements and summarized EPIC’s observations of SO2 from recent volcanic eruptions.

Simon Carn [University of Michigan] showed the first comparisons between the EPIC L2 volcanic SO2 product and SO2 retrievals from the Geostationary Environment Monitoring Spectrometer (GEMS) on the Korean GEO-Kompsat-2B satellite. GEMS observes East Asia as part of the new geostationary UV air quality (GEO-AQ) satellite constellation (which also includes TEMPO that observes North America and will include the Ultraviolet–Visible–Near Infrared (UVN) instrument on the European Copernicus Sentinel-4 mission, that will be launched in 2025 to observe Europe and surrounding areas) – but is not optimized for measurements of high SO2 columns during volcanic eruptions. EPIC SO2 data for the 2024 eruption of Ruang volcano in Indonesia are being used to validate a new GEMS volcanic SO2 product. Initial comparisons show good agreement between EPIC and GEMS before volcanic cloud dispersal and confirm the greater sensitivity of the hyperspectral GEMS instrument to low SO2 column amounts.

Aerosols

Alexei Lyapustin [GSFC] reported that the latest EPIC aerosols algorithm (V3) simultaneously retrieves aerosol optical depth, aerosol spectral absorption, and aerosol layer height (ALH) – achieving high accuracy. He showed that global validation of the single scattering albedo in the blue and red shows 66% and 81–95% agreement respectively, with Aerosol Robotic Network (AERONET) observations – which is within the expected error of 0.03 for smoke and dust aerosols. Lyapustin also reported on a comparison of EPIC aerosol data collected from 2015–2023 by the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP), which flew on the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) mission. The results show that ALH is retrieved with rmse ~1.1 km (0.7 mi). ALH is unbiased over the ocean and is underestimated by 450 m (1470 ft) for the smoke and by 750 m (2460 ft) for the dust aerosols over land. 

Myungje Choi and Sujung Go [both from University of Maryland, Baltimore County’s (UMBC), GESTAR II] presented results from a global smoke and dust characterization using Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm. This study characterized smoke and dust aerosol properties derived from MAIAC EPIC processing, examining spectral absorption, ALH, and chemical composition (e.g., black and brown carbon). Regions with smoldering wildfires, e.g., North America and Siberia, exhibited high ALH and a significant fraction of brown carbon, while Central Africa showed lower ALH with higher black carbon emissions.

Omar Torres [GSFC] discussed how L1 DSCOVR-EPIC observations are being used to study air quality (i.e., tropospheric O3 and aerosols) globally. Torres noted that this application of EPIC-L1 observations is of particular interest in the Southern Hemisphere (SH) where, unlike over the NH, there are currently no space GEO-based air quality measurements – and no plans for them in the foreseeable future.

Hiren Jethva [MSU, GESTAR II] presented the new results of the aerosol optical centroid height retrieved from the EPIC Oxygen-B band observations. He described the algorithm details, showed retrieval maps, and reviewed the comparative analysis against CALIOP backscatter-weighted measurements. The analysis showed a good level of agreement with more than 70% of matchup data within 1–1.5 km (0.6–0.9 mi) difference.

Jun Wang [University of Iowa] presented his team’s work on advancing the second generation of the aerosol optical centroid height (AOCH) algorithm for EPIC. Key advancements included: constraining surface reflectance in aerosol retrieval using an EPIC-based climatology of surface reflectance ratios between 442–680 nm; incorporating a dynamic aerosol model to characterize aged smoke particles; and employing a spectral slope technique to distinguish thick smoke plumes from clouds. Results show that both atmospheric optical depth (AOD) and AOCH retrievals are improved in the second generation of AOCH algorithm.

Olga Kalashnikova [NASA/Jet Propulsion Laboratory (JPL)] reported on improving brown carbon evolution processes in the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) model with EPIC products. She indicated that DSCOVR product evaluation, using lidar aerosol height measurements from CALIOP, led to an improved operational brown carbon product. To better resolve the temporal evolution of brown carbon, chemical transport models need to include more information about near-source fires.

Mike Garay [NASA/Jet Propulsion Laboratory (JPL)] discussed constraining near-source brown carbon emissions from 2024 Canadian ‘zombie’ fires with EPIC products. He reported that fires in British Columbia, Canada showed differences in brown carbon emission near the sources.  Garay explained that their investigation has revealed that these differences were related to fire intensity and variations in vegetation/soil content.

Yuekui Yang [GSFC] presented work that examined the impact of Earth’s curvature consideration on EPIC cloud height retrievals. Biases under the Plane Parallel (PPL) assumption is studied by comparing results using the improved pseudo-spherical shell approximation. PPL retrievals in general bias high and for a cloud with height of 5 km (3 mi), the bias is about 6%.

Alfonso Delgado Bonal [UMBC] stated that the EPIC vantage point offers a unique opportunity to observe not only the current state of the Earth but also its temporal evolution. By capturing multiple observations of the planet throughout the day, EPIC enables statistical reconstruction of diurnal patterns in clouds and other atmospheric parameters. Bonal’s team focused their research on O3 (primarily tropospheric) over the U.S. to demonstrate the presence of a diurnal cycle in the western regions of the continental U.S. However, ground-based data from PANDORA for specific locations do not support these diurnal variations – underscoring the critical role of space-based O3 retrievals. The proposed methodology is not limited to clouds or O3 but is broadly applicable to other EPIC measurements for the dynamic nature of our planet.

Elizabeth Berry [Atmospheric and Environmental Research (AER)] presented results from a coincident DSCOVR–CloudSat dataset [covering 2015–2020]. Cloud properties (e.g., cloud height and optical depth) from DSCOVR and CloudSat are moderately correlated and show quite good agreement given differences in the instruments sensitivities and footprints. Berry explained that a machine-learning model trained on the coincident data demonstrates high accuracy at predicting the presence of vertical cloud layers. However, precision and recall metrics highlight the challenge of predicting the precise location of cloud boundaries.

Anthony Davis [JPL] presented a pathway toward accurate estimation of the cloud optical thickness (COT) of opaque clouds and cloud systems, e.g., supercells, mesoscale convective complexes, and tropical cyclones (TCs). He described the approach, which uses differential oxygen absorption spectroscopy (DOAS) that has resolving power greater than 104 – which is comparable to that of the high-resolution spectrometers on NASA’s Orbiting Carbon Observatory–2 (OCO-2) – but is based upon the cloud information content of EPIC’s O2 A- and B-band radiances. Unlike the current operational retrieval of COT – which uses data from the Moderate Resolution Imaging Spectroradiometer (MODIS) on Terra and Aqua – the DOAS-based technique does not saturate at COT exceeding ~60. According to a popular TC model with two-moment microphysics, COT in a tropical storm or hurricane can reach well into the hundreds, sometimes exceeding 1000. Davis said that once the new COT estimates become available, they will provide new observational constraints on process and forecast models for TCs.

Ocean

Robert Frouin [Scripps Institution of Oceanography, University of California] discussed ocean surface radiation products derived from EPIC data. He explained that significant advancements have been achieved in processing and evaluating ocean biology and biogeochemistry products derived from EPIC imagery. V1 updates enhanced accuracy by integrating Modern-Era Retrospective analysis for Research and Applications V2 (MERRA-2) ancillary data and refining calculations for atmospheric and surface parameters. Frouin introduced several diurnal products, including hourly photosynthetically active radiation (PAR) fluxes, spectral water reflectance, and chlorophyll-a concentrations. He said that these new MODIS-derived products have been validated through comparisons with data from the Advanced Himawari Imager on the Japanese Himawar–8 and –9 satellites. In order to address the gaps in these diurnal products, Frouin explained that the team developed a convolutional neural network that has been used effectively to reconstruct missing PAR values with high accuracy.

Vegetation

Yuri Knyazikhin [Boston University] reported on the status of the Vegetation Earth System Data Record (VESDR) that provides a variety of parameters including: Leaf Area Index (LAI), diurnal courses of Normalized Difference Vegetation Index (NDVI), Sunlit LAI (SLAI), Fraction of incident Photosynthetically Active Radiation (FPAR) absorbed by the vegetation, Directional Area Scattering Function (DASF), Earth Reflector Type Index (ERTI), and Canopy Scattering Coefficient (CSC). Knyazikhin discussed analysis of the diurnal and seasonal variations of these quantities. EPIC LAI and FPAR are consistent with MODIS-derived measurements of the same parameters.

Jan Pisek [University of Tartu/Tartu Observatory, Estonia] discussed efforts to derive leaf inclination information from EPIC data. The very first evaluation over Tumbarumba site (in New South Wales, Australia) showed that the angular variation in parameters obtained from EPIC reflects the expected variations due to the erectophile vegetation present at the site.

Sun Glint

Tamás Várnai [UMBC, JCET] discussed EPIC observations of Sun glint from ice clouds. The cloud glints come mostly from horizontally oriented ice crystals and have strong impact in EPIC cloud retrievals. Várnai reported that the EPIC glint product is available from the ASDC – see Figure 4. Glint data can help reduce the uncertainties related to horizontally oriented ice crystals and yield additional new insights about the microphysical and radiative properties of ice clouds.

DSCOVR Figure 4
Figure 4. [top row] EPIC glint mask examples over land in [left to right] Paraguay, Sudan, Thailand, and Brazil. [bottom row] The corresponding EPIC glint mask for each image on the top row indicates the band (red, green and blue) and the size of sun glint for each of them.
Figure credit: Tamás Várnai (University of Maryland, Baltimore County)

Alexander Kostinski [Michigan Technology University] explained that because they detected climatic signals (i.e., longer-term changes and semi-permanent features, e.g., ocean glitter), they developed a technique to suppress geographic “noise” in EPIC images that involves introducing temporally (monthly) and conditionally (classifying by surface/cover type, e.g., land, ocean, clouds) averaged reflectance images – see Figure 5. The resulting images display seasonal dependence in a striking manner. Additionally, cloud-free, ocean-only images highlight prominent regions of ocean glitter.

DSCOVR Figure 5
Figure 5. Monthly reflectances for clear land pixels. Earth masquerading as Jupiter; latitudinal bright bands are caused by features such as the Sahara and Antarctica. Black spots are due to the lack or dearth of clear land pixels at that latitude. Repeated spots within latitudinal bands reflect roughly bi-hourly image sampling.
Figure credit: Alexander Kostinski (Michigan Technology University); from a 2024 paper published in Frontiers of Remote Sensing

Jiani Yang [Caltech] reported that spatially resolving light curves from DSCOVR is crucial for evaluating time-varying surface features and the presence of an atmosphere. Both of these features are essential for sustaining life on Earth – and thus can be used to assess the potential habitability of exoplanets. Using epsilon machine reconstruction, the statistical complexity from the time series data of these light curves can be calculated. The results show that statistical complexity serves as a reliable metric for quantifying the intricacy of planetary features. Higher levels of planetary complexity qualitatively correspond to increased statistical complexity and Shannon entropy, illustrating the effectiveness of this approach in identifying planets with the most dynamic characteristics.

Other EPIC Science Results

Guoyong Wen [MSU, GESTAR II] analyzed the variability of global spectral reflectance from EPIC and the integrated broadband reflectance on different timescales. He reported that on a diurnal timescale, the global reflectance variations in UV and blue bands are statistically similar – and drastically different from those observed in longer wavelength bands (i.e., green to NIR). The researchers also did an analysis of monthly average results and found that temporal averaging of the global reflectance reduces the variability across the wavelength and that the variability of broadband reflectance is similar to that for the red band on both timescales. These results are mainly due to the rotation of the Earth on diurnal timescale and the change of the Earth’s tilt angle. 

Nick Gorkavyi [Science Systems and Applications, Inc. (SSAI)] reported that EPIC – located at the L1 point, 1.5 million km (0.9 million mi) away from Earth – can capture images of the far side of the Moon in multiple wavelengths. These images, taken under full solar illumination, can be used to calibrate photographs obtained by lunar artificial satellites. Additionally, he discussed the impact of lunar libration – the changing view of the Moon from Earth, or it’s apparent “wobble” – on Earth observations from the Moon. 

Jay Herman [UMBC] discussed a comparison of EPIC O3 with TEMPO satellite and Pandora ground-based measurement. The results show that total column O3 does not have a significant photochemical diurnal variation. Instead, the daily observed diurnal variation is caused by weather changes in atmospheric pressure. This measurement result agrees with model calculations.

Conclusion

Alexander MarshakJay Herman, and Adam Szabo led a closing discussion with ST participants on how to make the EPIC and NISTAR instruments more visible in the community. It was noted that the EPIC website now allows visitors to observe daily fluctuations of aerosol index, cloud fraction, cloud height, and the ocean surface – as observed from the L1 point. More daily products, (e.g., aerosol height and sunlit leaf area index) will be added soon, which should attract more users to the website.

Overall, the 2023 DSCOVR EPIC and NISTAR STM was successful. It provided an opportunity for participants to learn the status of DSCOVR’s Earth-observing instruments, EPIC and NISTAR, the status of recently released L2 data products, and the science results being achieved from the L1 point. As more people use DSCOVR data worldwide, the ST hopes to hear from users and team members at its next meeting. The latest updates from the mission can be found on the EPIC website

Alexander Marshak
NASA’s Goddard Space Flight Center
alexander.marshak@nasa.gov

Adam Szabo
NASA’s Goddard Space Flight Center
adam.szabo@nasa.gov

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Feb 14, 2025

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      “There are really amazing participants in this project,” said Kuchner, who helped launch it in 2015. NASA’s WISE and NEOWISE missions detected about 2 billion sources in the sky. “So, the question is: Among those many sources, are any of them new unknowns?” he said.
      The project has already found more than 4,000 brown dwarfs. These are Jupiter-sized objects—balls of gas that are too big to be planets, but too small to be stars. Volunteers have even helped discover a new type of brown dwarf.
      Participants in the project are also hopeful they’ll find a hypothetical ninth planet, possibly Neptune-sized, in an orbit far beyond Pluto.
      The Backyard Worlds: Planet 9 citizen science project asks volunteers to help search for new objects at the edge of our solar system. The assignment is to review images from NASA’s past WISE and NEOWISE missions in search of two types of astronomical objects: brown dwarfs(balls of gas the same size as  Jupiter that have too little mass to be considered stars) and low-mass stars. Or, even, the hypothetical ninth planet of our Sun, known as Planet nine, or Planet X. The image shows an artist’s rendering of such a hypothetical world orbiting far from the Sun.
      Credit: Caltech/R. Hurt (IPAC) Caltech/R. Hurt (IPAC) Burgos explained that analyzing the images is easy. “If it’s a moving object, it’s obviously going to be something of interest,” he said. “Usually, when you see these images, everything is still. But if there’s an object moving, you have to keep an eye on it.”
      Once a citizen scientist marks the object across the full image sequence, they send the information to NASA scientists to evaluate.
      “As a citizen scientist, I’m happy to do my bit and, hopefully, one day discover something very interesting,” he said. “That’s the beauty of NASA—it invites everyone to be a scientist. Here, it doesn’t matter what you are, but your desire to learn.”
      The first step
      To become a NASA citizen scientist, start by visiting the program’s website. There you’ll find a complete list of available projects with links to their respective sites. Some are available in Spanish and other languages. Many projects are also hosted on the Zooniverse platform, which has been available since 2006.
      “Another cool way to get involved is to come to one of our live events,” said Kuchner. These are virtual events open to the public, where NASA scientists present their projects and invite people to participate. “Pick a project you like—and if it’s not fun, pick a different one,” he advised. “There are wonderful relationships to be had if you reach out to scientists and other participants.”
      Another way for people to get involved in citizen science is to participate in the annual NASA International Space Apps Challenge, the largest global hackathon. This two-day event creates innovation through international collaboration, providing an opportunity for participants to use NASA’s free and open data and agency partners’ space-based data to tackle real-world problems on Earth and in space. The next NASA International Space Apps Challenge will be October 4-5, 2025.
      Credit: NASA Age is not the limit
      People of all ages can be citizen scientists. Some projects are kid-friendly, such as Nemo-Net, an iPad game that invites participants to color coral reefs to help sort them. “I’d like to encourage young people to start there—or try a project with one of the older people in their life,” Kuchner said.
      Citizen science can also take place in classrooms. In the Growing Beyond Earth project, teachers and students run experiments on how to grow plants in space for future missions. The IASC project also works with high schools to help students detect asteroids.
      A student waters small plants inside a Growing Beyond Earth citizen science project grow box.
      Credit: NASA Projects by the community, for the community
      GLOBE Observer is another initiative with an international network of teachers and students. The platform offers a range of projects—many in Spanish—that invite people to collect data using their cell phones.
      One of the most popular is the GLOBE Mosquito Habitat Mapper, which tracks the migration and spread of mosquitoes that carry diseases. “It’s a way to help save lives—tracking the vectors that transmit malaria and Zika, among others,” Kuchner said.
      Other GLOBE projects explore everything from ground cover to cloud types. Some use astronomical phenomena visible to everyone. For example, during the 2024 total solar eclipse, participants measured air temperature using their phones and shared that data with NASA scientists.
      The full experience of doing science
      No prior studies are needed, but many volunteers go on to collaborate on—or even lead—scientific research. More than 500 NASA citizen scientists have co-authored scientific publications.
      One of them is Hugo Durantini Luca, from Córdoba, Argentina, who has participated in 17 published articles, with more on the way. For years, he explored various science projects, looking for one where he could contribute more actively.
      Durantini Luca participated in one of NASA’s first citizen science projects, launched in 2006: Stardust at home. Still ongoing, this project invites volunteers to participate in the search for evidence of interstellar dust on the aerogel and aluminum foil collectors returned by NASA’s Stardust mission, using an online virtual microscope.
      Credit: NASA He participated in NASA’s first citizen science project, Stardust@home, which invites users to search for interstellar dust particles in collectors from the Stardust mission, using a virtual microscope.
      In 2014, he discovered Disk Detective, a project that searches for disks around stars, where planets may form. By looking at images from the WISE and NEOWISE missions, participants can help understand how worlds are born and how solar systems evolve.
      “And, incidentally, if we find planets or some sign of life, all the better,” said Durantini Luca.
      Although that remains a dream, they have made other discoveries—like a new kind of stellar disk called the “Peter Pan Disk,” which appears young even though the star it surrounds is not.
      Durantini Luca participated in one of NASA’s first citizen science projects, launched in 2006: Stardust at home. Still ongoing, this project invites volunteers to participate in the search for evidence of interstellar dust on the aerogel and aluminum foil collectors returned by NASA’s Stardust mission, using an online virtual microscope.
      Credit: NASA Science in person
      In 2016, Durantini Luca got the chance to support Disk Detective with his own observations from the southern hemisphere. He traveled to El Leoncito Astronomical Complex (CASLEO), an observatory in San Juan, Argentina. There, he learned to use a spectrograph—an instrument that breaks down starlight to analyze its composition.
      He treasures that experience. “Curiously, it was the first time in my life I used a telescope,” he said.
      In 2016, citizen scientist Hugo Durantini Luca traveled for 18 hours to the El Leoncito Astronomical Complex (CASLEO), at the foot of the Andes Mountains. From there, he made observations of a candidate star of the Disk Detective project.
      Credit: Luciano García While in-person opportunities are rare, both virtual and physical events help build community. Citizen scientists stay in touch weekly through various channels.
      “Several of us are friends already—after so many years of bad jokes on calls,” said Durantini Luca.
      “People send me pictures of how they met,” said Kuchner. He said the program has even changed how he does science. “It’s changed my life,” he said. “Science is already cool—and this makes it even cooler.”
      About the Author
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      Last Updated Apr 29, 2025 Related Terms
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      Brooks P. Age 8mo. “Squiggles” About the Author
      Milan Loiacono
      Science Communication SpecialistMilan Loiacono is a science communication specialist for the Earth Science Division at NASA Ames Research Center.
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      Michael P. Thelen, SPHEREx Observatory Flight System Manager, rings the bell alongside NASA SPHEREx team members at the New York Stock Exchange Tuesday, April 25, 2025. Image courtesy of NYSE Group More About SPHEREx
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      News Media Contacts
      Alise Fisher
      NASA Headquarters, Washington
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      Calla Cofield
      Jet Propulsion Laboratory, Pasadena, Calif.
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      calla.e.cofield@jpl.nasa.gov
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      News Media Contacts
      Andrew Good
      Jet Propulsion Laboratory, Pasadena, Calif.
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      Karen Fox / Molly Wasser
      NASA Headquarters, Washington
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      karen.c.fox@nasa.gov / molly.l.wasser@nasa.gov
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