This roof-mounted air sensor in Addis Ababa, the capital of Ethiopia, is one of 10 used by NASA’s Multi-Angle Imager for Aerosols (MAIA) to study the city’s air quality. MAIA’s air sensors provide a detailed look at particulate matter that is 2.5 micrometers or less in diameter, also known as PM2.5, one of the world’s deadliest forms of air pollution.
Black carbon, or soot, is an important component of particulate pollution in Addis Ababa and is produced by diesel vehicles, fires, and other combustion sources. Detailed measurements from the MAIA air sensors reveal how pollution changes by time of day and season, including spikes produced by rush-hour traffic and holiday celebrations. The findings are relevant to cities around the world, including in the United States.
The 2025 State of Global Air Report, cited in the paper, estimates that these particles, some of which are tiny enough to enter the human bloodstream, are linked to around 4.9 million excess deaths per year globally. Of the many kinds of PM2.5, black carbon in particular has been linked to impacts on low birth weight, brain development, respiratory conditions, and premature mortality.
Mapping Air Pollution With MAIA Sensors in Addis Ababa
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Mapping Air Pollution With MAIA Sensors in Addis Ababa
PIA26694
Credits: NASA/JPL-Caltech
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Mapping Air Pollution With MAIA Sensors in Addis Ababa
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This map of Addis Ababa, the capital of Ethiopia, shows the locations of 10 air sensors that NASA’s Multi-Angle Imager for Aerosols (MAIA) mission is using to provide one of the most detailed looks ever at the city’s air pollution. Over the course of three years, these sensors measured particulate matter that is 2.5 micrometers or less in diameter, also known as PM2.5. Black carbon, or soot, is an important component of particulate pollution in Addis Ababa, which studies have linked to impacts on low birth weight, brain development, respiratory conditions, and premature mortality.
The color bar at right indicates air quality variations from 20 to 40 micrograms per cubic meter across the monitoring stations, with the darkest red being the poorest air quality.
In Ethiopia, black carbon is commonly produced by diesel vehicles, fires, and other combustion sources. Detailed measurements from the MAIA sensors reveal how Addis Ababa’s air pollution changes by time of day and season, including spikes produced by rush-hour traffic and holiday celebrations. The findings are relevant to cities around the world, including in the United States.
MAIA’s air pollution research is focused on a dozen regions around the globe, including three in the U.S. centered on Los Angeles, Atlanta, and Boston. The mission consists of a ground-based sensor network already in operation as well as a space observatory, which uses a camera built at NASA’s Jet Propulsion Laboratory, that will be launched by the Italian Space Agency (ASI) on an ASI satellite no earlier than late 2027. The camera is specially designed to help identify different types of PM2.5 aerosols based on how they reflect light, making it possible to map particle concentrations over each region that the mission studies.
The rugged terrain of the Silver Island Mountains and Crater Island rises above the pale playa and bright salt flats of former Lake Bonneville. The image was acquired with the OLI (Operational Land Imager) on Landsat 8 on June 4, 2026, and overlaid on a digital elevation model.
NASA Earth Observatory/Michala Garrison
At its peak, ancient Lake Bonneville would have been a sight to behold. Nearly as large as Lake Michigan, the Ice Age lake spread across much of western Utah and parts of Nevada and Idaho. When it eventually receded, it left behind flat, bright playas and salt flats rich with minerals—a landscape that would later serve as the setting for feats of engineering and technological ingenuity, as well as epic tales of exploration and desperation.
Lake Bonneville began forming about 55,000 years ago during a cool, wet period, when volcanic eruptions in what’s now southeastern Idaho diverted the Bear River, causing water to gather in Gem Valley and other basins to the south. For tens of thousands of years, a natural dam at Red Rock Pass helped confine the lake.
Then, about 18,000 years ago, water breached that dam, unleashing a torrent that entered the Columbia River system. Over a six-week period, amid one of North America’s largest floods, lake levels plummeted by more than 350 feet (105 meters). As the climate warmed and dried in subsequent millennia, the lake shrank dramatically, leaving remnants that include today’s Great Salt Lake, Utah Lake, and Sevier Lake.
Lake Bonneville may be gone, but its imprint on the region’s landscape remains—even in satellite imagery. In this image (below) captured by the OLI (Operational Land Imager) on the NASA-USGS Landsat 8 satellite, bathtub-like rings and wave-cut terraces trace the position of former shorelines. The dried lakebed—where fine-grained clay, marl, and sandy sediment settled out of the water—appears pale in comparison to the darker, rockier, more vegetated surroundings.
NASA scientists analyzed the terrain in this part of Utah when testing technologies that will be used on NASA’s DAVINCI mission to Venus. This image was acquired with the OLI (Operational Land Imager) on Landsat 8 on June 4, 2026.
NASA Earth Observatory/Michala Garrison
In deep parts of the basin, where runoff and groundwater still pool, bright deposits of evaporite minerals coat the land surfaces, forming salt flats. These remarkably flat surfaces are the product of water gradually evaporating and concentrating minerals to produce brines and hard mineral crusts, typically including halite and gypsum, along with potassium- and magnesium-bearing salts. Brines and deposits like these—particularly of potash, which is used as a fertilizer—have long made the playa a target for mining, as seen in the rectangular evaporation ponds above and below.
In contrast, the darker, more rugged terrain—including the Silver Island Mountains, the Newfoundland Mountains, and the Pilot Range—that rises above the playas is built from layers of erosion-resistant sedimentary and metasedimentary bedrock that is hundreds of millions of years old. These mountains also contain younger igneous and metamorphic rocks that formed when magma intruded into the ancient sedimentary sequence.
Crater Island, for instance, is composed of sedimentary rocks, including silica-rich sandstones and quartzites that formed as sands accumulated in a shallow ocean, as well as intrusions of quartz monzonite, granites, and other igneous rocks. Periods of crustal stretching later produced the fault-block mountains that define the landscape.
This animation shows the descent over Crater Island, Utah, of the camera system that will one day fly aboard NASA’s DAVINCI mission to Venus. It was created by stitching together 37 infrared images captured during a test on June 24, 2026.
Malin Space Science Systems/NASA/Jay Friedlander
Mapping geological distinctions like this took center stage in June 2026 when NASA scientists and engineers working with the agency’s DAVINCI mission came to Crater Island—a place they call “Venus on Earth”—to field-test the design of a set of cameras and a package of instruments that will eventually descend through the thick atmosphere of Venus and photograph mountains at scales finer than these Landsat images. During a 60-minute descent, the pioneering probe will capture near-infrared images, measure the atmospheric chemistry, and explore the environment of a world in unprecedented detail.
During the rehearsals at Crater Island, the camera system took hundreds of images of various rock formations, including iron-rich and silica-rich rock units, while suspended from a helicopter as it descended toward the surface. Using only the images acquired by DAVINCI’s camera systems, the team made three-dimensional maps of the area consistent with existing geologic maps, giving the scientists confidence that they will be able to map the geology of an analogous mountainous region on Venus that DAVINCI will study, an area called Alpha Regio.
Other epic adventures have played out on and around Lake Bonneville’s playas, as well. The flat, smooth surfaces have often been the setting for new land speed records. In 1960, Mickey Thompson became the first American to break the 400-miles-per-hour (640 kilometers-per-hour) barrier, hitting 406.60 miles per hour (654.36 kilometers per hour) in a streamlined race car on the Bonneville Salt Flats. The feat temporarily earned him the nickname “fastest man on Earth.”
People mine minerals from the Bonneville Salt Flats and use its flat surface to pursue land speed records. This image was acquired with the OLI (Operational Land Imager) on Landsat 8 on June 4, 2026.
NASA Earth Observatory/Michala Garrison
More recently, in August 2026, Andy Green, the first person to break the sound barrier on land, set a record for the fastest land speed in a hydrogen-fueled internal-combustion vehicle, reaching 406.320 miles per hour (653.909 kilometers per hour). By burning hydrogen rather than gasoline, the “rocket car” produced no carbon dioxide.
Nearly two centuries earlier, in August 1846, members of the ill-fated Donner-Reed Party also passed along the southern edge of Crater Island. As part of a shortcut toward Pilot Peak, they journeyed from Hastings Pass, past Floating Island, and toward Donner Spring. However, in an ominous sign of challenges to come, their heavy wagons broke through the thin salt crust and became mired in underlying mud, slowing them down and prompting them to abandon several wagons in the desert.
NASA Earth Observatory images by Michala Garrison, using Landsat data from the U.S. Geological Survey.Story by Adam Voiland.
Curiosity Blog, Sols 4982–4987: Back to Our Regularly Scheduled Programming
3 min read
Curiosity Blog, Sols 4982–4987: Back to Our Regularly Scheduled Programming
NASA’s Mars rover Curiosity acquired this image, of thin, ledge-like layers at target “Los Toldos,” using its Right Mast Camera (Mastcam). Curiosity captured the image on Aug. 12, 2026 — Sol 4982, or Martian day 4,982 of the Mars Science Laboratory mission — at 01:05:04 UTC.
NASA/JPL-Caltech/MSSS
By Allison Dries-Padilla, Missions Operations Specialist at Malin Space Science Systems
Earth planning date: Friday, Aug. 14, 2026
This week of Curiosity Mars rover operations takes us back to our “regularly scheduled programming.” After taking a slight detour to investigate the “erosional surface” we are back on course to ascend Mount Sharp. As we transition into fall in Gale Crater, temperatures and the likelihood of dust storms begins to drop, but Curiosity is still on the lookout for the last gasp of late-season local and regional dust storms.
Monday’s plan for Sols 4982 to 4985 began with Curiosity standing face to face with a unique geologic feature just above the erosional supersurface contact. As you might have read in the previous blog, the team was fortunate enough to spend two planning cycles at this amazing location. MAHLI used this opportunity to reacquire selected images for the mosaic of target “Tres Morros.” This will allow the science team to have a detailed and focused view of the underside of this feature. APXS took measurements of the bedrock target “El Motacusal” after it had been brushed with the DRT. APXS took a second measurement on the “as is” bedrock target “Alto de Carmen.” Both of these APXS targets were documented with high-resolution images taken by MAHLI. ChemCam activities include LIBS spectroscopy on bedrock targets “Lagunas Bravas” and “Parququcha” and ChemCam Remote Micro-Imaging on Mishe Mokwa. I had the pleasure to be on the Mastcam uplink shift for this plan. Mastcam took a near-field mosaic of the erosional ridge, dubbed “Los Toldos,” as well as a mosaic on further away bedrock exposure above the erosional surface, named “Los Ladrillos.” In addition to these mosaics, Mastcam also provided color documentation of the previous plan’s ChemCam Remote Micro-Imaging on Cordillera and the ChemCam LIBS activities taken in this plan.
Curiosity then drove 100 feet (30 meters) to take us to our location for Friday’s plan for Sols 4985 to 4987. Although we had plenty of flat and tasty bedrock in this new location, we could not place the robotic arm in a safe position to DRT the bedrock. The left-front wheel was perched on a small rock, and we had to account for a risk the rover could slip off this rock as we move the arm around. MAHLI and APXS were still able to safely perform contact science on two bedrock targets, “Mamorecillo” and “Aguas Claras.” MAHLI had an additional housekeeping activity to image the calibration target. ChemCam plans to use its laser spectrometer to gather geochemistry on three targets in this vicinity, followed by Mastcam documentation. Today’s ChemCam LIBS targets include a dark-toned resistant layer in the bedrock “Yura Kasa.” Mastcam is planning a series of mosaics to continue imaging the stratigraphy in the unit above the erosional contact.
Today’s plan was packed with environmental monitoring activities to monitor for dust storms. Mastcam took a flurry of dust-imaging observations to measure optical depth, or “tau,” of the atmosphere. A higher tau value is associated with an increased amount of dust in the atmosphere. APXS joined in on the action by planning an overnight atmospheric measurement. Navcam took on most of the heavy lifting to monitor for dust storms. These activities include multiple large dust-devil surveys, zenith observation, in-crater line-of-sight observations, and suprahorizon cloud movies.
Curiosity will then continue to climb Mount Sharp; the planned drive distance of 150 feet (47 meters) will take the rover southwest of our current location. We will return Monday to start a new week full of contact science, remote sensing, and driving on Mars.
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Mostly Perseids
Explanation: Recorded the night of August 12-13, images from four dedicated meteor-monitoring cameras at an astronomical observatory in Czechia were aligned and combined to create this all-night, all-sky view. On that night, the total count came to 1,706 meteors. And since that coincided with the peak activity of the 2026 Perseid Meteor Shower, most are perseids. Their overwhelming numbers make them easy to spot. Quite convincingly, perseid trails all trace back to a single radiant on the sky at the upper right, a region in the annual shower’s eponymous constellation Perseus. But meteors belonging to other much less active showers can be revealed by finding their radiants too. For example, seen crossing the perseid trails are meteors from a shower whose radiant lies in Cygnus, known as Kappa Cygnids. The antihelion complex, a general region near Aquarius and opposite the Sun in the sky, is also identifiable as a weak source for meteors.
