Tuesday, 17 March 2026

A Bit of Gray on an Emerald Isle

A detailed view of folded limestone in the Burren. The limestone forms swirling, layered patterns of gray rock separated by thin green bands of vegetation.
May 16, 2025

Today’s story is the answer to the March 2026 puzzler.

Though Ireland is known for the many shades of green that grace its grassy pastoral landscapes, there’s one corner of the Emerald Isle where gray reigns supreme. In the Burren region, on the island’s west coast, what geologists describe as limestone pavement covers much of the rocky, treeless landscape.

The OLI (Operational Land Imager) on Landsat 8 captured this view of the Burren on May 16, 2025. The fossil-rich limestone that makes up the gray outcrops was deposited about 325 million years ago during the Carboniferous Period, when what is now Ireland lay near the equator beneath warm, shallow seas. Although the limestone was initially deposited in flat, horizontal layers on the seafloor, it later buckled into gentle arch- and trough-shaped folds as tectonic plates collided during a mountain-building episode known as the Variscan Orogeny.

These folds in the tilted rock layers and differences in their rate of erosion produced the terraced appearance that defines the Burren’s hills, with more erosion-resistant layers of rock persisting as ledges. Glacial activity also played a role in sculpting the landscape, scraping away soil and sediment to expose the limestone pavement and smoothing the region’s hills.

A satellite view of the Burren in western Ireland shows gray limestone hills arranged in curved, concentric bands surrounded by green farmland and small towns.
May 16, 2025

Limestone is prone to chemical weathering that produces an irregular terrain known as karst, pockmarked with sinkholes, caves, and fissures called grikes. Many grikes in the Burren collect soil and have become footholds where vegetation grows in the otherwise rocky landscape.

Individual grikes are too small to see in Landsat imagery, but networks of them have aligned along the rock layers, contributing to the concentric vegetation patterns visible in the image. Among the plants that you might find growing in them is the shamrock, the three-leaved clover that has become a symbol of Ireland.

With some luck, Trifolium dubium or Trifolium repens may even be found amidst the shamrock-shaped contours of Moneen Mountain, a 262-meter (860-foot) limestone hill visible in the image above. While there’s hardly consensus about what species is the true inspiration for shamrocks, these two clover species were among the favorites when Irish botanists were surveyed about the topic in the 1880s, according to the Carnegie Museum of Natural History.

NASA Earth Observatory images by Lauren Dauphin, using Landsat data from the U.S. Geological Survey. Story by Adam Voiland.

Downloads

A satellite view of the Burren in western Ireland shows gray limestone hills arranged in curved, concentric bands surrounded by green farmland and small towns.

May 16, 2025

JPEG (3.01 MB)

References & Resources

You may also be interested in:

Stay up-to-date with the latest content from NASA as we explore the universe and discover more about our home planet.
An Amphitheater of Rock at Cedar Breaks
4 min read

The colorful formations found in this bowl-shaped escarpment in southwestern Utah are the centerpiece of Cedar Breaks National Monument.

Article
The Towers of Tràng An
3 min read

Over millions of years, water has sculpted limestone in northern Vietnam into an extraordinary karst landscape full of towers, cones,…

Article
Rewilding South Africa’s Greater Kruger
5 min read

Satellites are helping land managers track ecological shifts as reserves reconnect and landscapes return to a more natural state.

Article


from NASA https://ift.tt/KZTM9t3
at No comments:
Labels:

To Protect Artemis II Astronauts, NASA Experts Keep Eyes on Sun 

7 min read

To Protect Artemis II Astronauts, NASA Experts Keep Eyes on Sun 

As four astronauts travel around the Moon on NASA’s Artemis II mission, they will venture beyond Earth’s protective magnetic field. The crew’s spacecraft, Orion, will carry and protect them as they journey into deep space and serves as the main protection against the Sun’s intense power.  During their 10-day flight, NASA and the National Oceanic and Atmospheric Administration (NOAA) will monitor the Sun around the clock and translate space weather conditions into real-time decisions to protect the astronauts. 

Space weather refers to the changing conditions driven by solar wind and eruptions from the Sun. Solar flares are the most powerful eruptions in the solar system, the strongest unleashing more energy than a billion hydrogen bombs. Coronal mass ejections are giant clouds of solar particles hundreds of times the size of Earth that burst from the Sun.  

While both flares and coronal mass ejections can affect technology, the primary concern for astronauts is the solar particle events they can trigger, accelerating some particles to near light speed. If a significant solar particle event occurs near the Artemis II crew, it could raise radiation levels inside the spacecraft. Too high a total lifetime exposure can contribute to increased risks of developing cancer or health disorders that could impair cognition and performance. During the Artemis II mission, NASA will minimize that risk.

For the first time in half a century, four astronauts are leaving Earth’s protective magnetic field to enter a realm where massive solar eruptions can unleash more energy than a billion hydrogen bombs. The Artemis II crew will fly through a dangerous environment, but they’re not going it alone. On the voyage, the astronauts and their Orion capsule are outfitted with radiation trackers as ground teams monitor solar eruptions 24/7. Here’s how NASA and the National Oceanic and Atmospheric Administration (NOAA) are protecting explorers from the most powerful eruptions in the solar system.
NASA/Joy Ng

Tracking solar eruptions 

“Our focus will be real-time space weather analysis, prioritizing solar energetic particles and events that could produce them,” said Mary Aronne, operations lead for the space weather analysis office at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “We’re looking for the trigger, which would typically be a flare or a coronal mass ejection.” 

This animation shows a solar eruption that produces a solar flare, a coronal mass ejection, and a flurry of energetic particles. The particles follow the spiral shape of the solar wind’s magnetic fields into interplanetary space.
NASA’s Goddard Space Flight Center Conceptual Image Lab

The Goddard team will track any solar eruptions that occur, measuring how big they are, how fast they’re moving, and how likely they are to generate energetic particles that will cross Orion’s path. To this end, they’ll use real-time data from Sun-watching spacecraft strategically placed across the solar system, such as NASA’s recently launched Interstellar Mapping and Acceleration Probe, NASA’s Solar Dynamics Observatory, the ESA (European Space Agency)/NASA Solar and Heliospheric Observatory, NOAA’s Geostationary Operational Environmental Satellites-19 satellite, and many others. 

Other NASA spacecraft also will help monitor the Sun. Due to Mars’ current position, NASA’s Perseverance Mars rover can look at the far side of the Sun, where Earth has no view. The rover’s Mastcam-Z cameras can give NASA’s space weather teams a view of the largest sunspots up to two weeks earlier so the team can monitor and prepare for possible solar flares.  

NASA’s Perseverance Rover captured these images of sunspots crossing the Sun from its vantage point on the Martian surface between February 24 – 27, 2026. Mars is currently on the opposite side of the Sun, giving the rover a view of sunspots not visible from Earth. Perseverance will monitor sunspots leading up to and during the Artemis II launch window, giving the Moon to Mars Space Weather Analysis Office (M2M SWAO) and Space Radiation Analysis Group (SRAG) teams advance notice of regions that could produce solar eruptions before they rotate onto the Earth-facing side of the Sun.
NASA/JPL-Caltech/ASU/MSSS/SSI

Monitoring crew exposure 

Energetic solar particles don’t stream straight out from the Sun. They spiral along the Sun’s magnetic field lines, tracing loops tens of thousands of miles across and scattering due to particle collisions along the way. The chaotic swarm is so large that, from inside it, particles seem to be coming from every direction.  

“It’s more like you’re sitting in a bathtub and it’s gradually filling with water,” said Stuart George, a space radiation analyst at NASA Johnson. 

That gradual rise in radiation gives analysts time to evaluate the situation. Inside Orion, six radiation sensors, part of the Hybrid Electronic Radiation Assessor system designed and built by NASA, measure dose rates in different parts of the cabin. Artemis II astronauts also wear personal radiation trackers called crew active dosimeters. If radiation levels increase, Orion’s onboard systems display warnings accompanied by an audible alarm. 

Exploded diagram of NASA's Orion spacecraft showing labeled parts: spacecraft adapter, service module, crew module, and launch abort system, with various components highlighted against a gray background.
Artist’s concept of the components of the Orion spacecraft.
NASA

NASA has dosage level thresholds they’ll look for inside Orion. The first threshold signals a caution, prompting closer monitoring and coordination with medical and flight operations teams. A higher threshold triggers a recommendation for the crew to take shelter. 

Radiation shielding in space is all about mass. Charged particles are slowed and absorbed as they pass through matter. Astronauts are trained to reconfigure their cabin during a solar particle event, removing stowed equipment from storage bays and securing it along areas of the cabin to add mass between themselves and incoming particles. Since Artemis II is the first crewed Artemis mission, testing this procedure in the Orion spacecraft is a major objective of the mission. 

“Once crews add mass to the places that tend to be hotter in terms of radiation exposure, they can then continue to go about their duties,” George said. 

Artist’s concept of the Trajectory for Artemis II, NASA’s first flight with crew aboard SLS and Orion to pave the way for long-term return to the Moon and missions to Mars.
NASA

The complexity of solar particle events is one reason NASA places spacecraft across the solar system. During a solar storm in January, NASA analysts tracked a coronal mass ejection on its way to Earth. When it arrived, satellites detected two distinct spikes in energetic particles where there would normally be one. Measurements from NASA’s BioSentinel CubeSat, deployed during the Artemis I mission, revealed what happened. The spacecraft, about 55 million miles away from Earth, detected a distinct eruption that later merged with the coronal mass ejection headed to Earth. Ultimately, two separate eruptions occurred.

The crew also must account for exposure to Earth’s radiation belts and galactic cosmic rays. The Van Allen Radiation Belts are two rings of high energy particles that surround our planet. Any mission headed to the Moon or farther must pass through them. Galactic cosmic rays are very high-energy particles from sources beyond our solar system. Together, the radiation exposure from these sources is expected to be comparable to a 1-month stay on the International Space Station, or about 5% of an astronaut’s career limit. Any exposure from solar radiation events would add to this baseline. 

The Moon to Mars Space Weather Analysis Office, based at NASA Goddard, continuously assesses solar activity and any eruptions that occur. The team shares its analysis with the Space Radiation Analysis Group, based at NASA’s Johnson Space Center in Houston. Together, their forecasts and those from NOAA’s Space Weather Prediction Center, plus real-time measurements from inside the Orion spacecraft will inform recommendations for the flight control team.  

By Miles Hatfield
NASA’s Goddard Space Flight Center, Greenbelt, Md.

Explore More



from NASA https://ift.tt/0cah4uJ
at No comments:
Labels:

Monday, 16 March 2026

Cañon Fiord’s Whirling Waters

A V-shaped fjord cuts through barren brown land, with one patch of swirling water marked by white sea ice and another one colored turquoise by suspended sediment. Glacial ice flows into the fjord in several places.
August 9, 2022

For most of the year, ice blankets the waterways of the northern Canadian Arctic Archipelago. But during the brief summer melt season, the stark white and gray landscape transforms into a colorful, dynamic environment. On a particularly striking day in 2022, sediment plumes and fractured sea ice traced swirling eddies in a branch of the Nansen Sound fjord system.

These satellite images show a section of Cañon Fiord, located about 115 kilometers (70 miles) southeast of the Eureka research station on west-central Ellesmere Island. Waters from the fjord flow into Greely Fiord, which connects to Nansen Sound and ultimately the Arctic Ocean. The images were acquired by the OLI (Operational Land Imager) on Landsat 8 on August 9, 2022.

Igor Dmitrenko, a physical oceanographer at the Centre for Earth Observation Science at the University of Manitoba, has studied eddies in the fjord system and notes that the water’s turbidity, a measure of its cloudiness, remains low during the ice-covered season. Freshwater runoff—and the sediment it carries—drops sharply this time of year, and the formation of 2-meter-thick sea ice shields the surface from wind, suppressing mixing that would otherwise resuspend particles.

Summer presents a contrasting scenario. The detailed image below (top) shows that the sea ice in this part of the fjord has broken up, free to drift with the currents and wind. Note that some of the pieces are likely icebergs that have broken off from nearby outlet glaciers. The second detailed image shows a similar scenario; however, in this case, it is sediment suspended in the water that is tracing the flow.

Blue fjord waters with white sea ice swirling in a circular eddy.
August 9, 2022
Fjord waters with sediment swirling in a circular eddy, making the water appear light turquoise.
August 9, 2022

Alex Gardner and Chad Greene, glaciologists at NASA’s Jet Propulsion Laboratory, pointed out that the sediment plume is mostly glacial flour—rock that has been pulverized by a glacier. Surface meltwater that gets under the glacier ultimately flushes the glacial flour into the fjord, making the water appear turquoise. Glacial flour is a critical source of nutrients, specifically iron. Soluble iron is a vital nutrient in marine ecosystems because most phytoplankton—the foundation of marine food webs—depend on it to grow. 

The glacial ice visible in these scenes comes from the Agassiz Ice Cap, one of five major ice caps on Ellesmere Island. Using data from NASA’s ICESat and the DLR-NASA GRACE missions, scientists have shown that glaciers in the Canadian Arctic Archipelago began shrinking rapidly in the mid-2000s and that the trend has persisted.

NASA Earth Observatory images by Lauren Dauphin, using Landsat data from the U.S. Geological Survey. Story by Kathryn Hansen.

Downloads

A V-shaped fjord cuts through barren brown land, with one patch of swirling water marked by white sea ice and another one colored turquoise by suspended sediment. Glacial ice flows into the fjord in several places.

August 9, 2022

JPEG (11.98 MB)

References & Resources

You may also be interested in:

Stay up-to-date with the latest content from NASA as we explore the universe and discover more about our home planet.
Arctic Sea Ice Ties for 10th-Lowest on Record
3 min read

Satellite data show that Arctic sea ice likely reached its annual minimum extent on September 10, 2025.

Article
Stonebreen’s Beating Heart
3 min read

The glacier in southeastern Svalbard pulses with the changing seasons, speeding up and slowing its flow toward the sea.

Article
Antarctic Sea Ice Saw Its Third-Lowest Maximum
2 min read

Sea ice around the southernmost continent hit one of its lowest seasonal highs since the start of the satellite record.

Article


from NASA https://ift.tt/gz5Mqnk
at No comments:
Labels:

Saturday, 14 March 2026

Volunteers Find Oddly High Solar Flare Rates

2 min read

Volunteers Find Oddly High Solar Flare Rates

Patches of the Sun’s surface often show strong magnetic fields. These fields can emerge within a matter of hours, and can decay slowly or quickly, sometimes over days, weeks, or even months. Thanks to a new study about these long-lived active regions, we now know much more about the patches where these strong magnetic fields take at least a month to decay.

This study relied on inputs from NASA’s Solar Active Region Spotter citizen science project, which asked volunteers to answer a series of questions about pairs of active region images from NASA’s Solar Dynamics Observatory.

Project leads Emily Mason (Predictive Science Inc.) and Kara Kniezewski (Air Force Institute of Technology) looked at the data and the analysis done by volunteers. They found that the long-lived active regions produce disproportionately more flares than the shorter-lived regions and are 3-6 times more likely than other active regions to be the source of the most intense kinds of solar flares. These results are a strong indication that long-lived active regions are crucial for predicting space weather and could provide critical information on magnetic fields deeper inside the Sun. 

The Solar Active Region Spotter project is now complete, but you can learn more about the results here: https://www.zooniverse.org/projects/eimason/solar-active-region-spotter/about/results

Explore NASA Citizen Science projects you can join today to help advance our understanding of space weather: https://go.nasa.gov/3ZK6nvE.

An example of the data citizen scientists categorized for this project.
An example of the data citizen scientists categorized for this project.
NASA

Learn More and Get Involved

An image of the sun's atmosphere which has green eruptive areas on it. Overlaying the sun is an illustration of a crosshairs with a white center filled with red and purple dots representing data. The text Solar Active Region Spotter follows the arc of the top hemisphere of the sun.

Solar Active Region Spotter

Help track active regions as they evolve across solar rotations!

Share

Details

Last Updated
Mar 13, 2026
Editor
NASA Science Editorial Team

Explore More



from NASA https://ift.tt/Q2ahFng
at No comments:
Labels:

Extra Extra! Extra Data Stream Added to the Daily Minor Planet!

2 min read

Extra Extra! Extra Data Stream Added to the Daily Minor Planet!

The Daily Minor Planet citizen science project is expanding! In addition to data received nightly from the Catalina Sky Survey’s Mt. Lemmon telescope in Arizona, the project’s science team is now processing images from the Bok 2.3-meter telescope at Kitt Peak National Observatory. The Bok is a mighty telescope run by the University of Arizona’s Steward Observatory that is used to survey for new near-Earth objects (NEOs) – asteroids that cross Earth’s orbit.

Data from the Bok telescope peers deeper than the data from the Mt. Lemmon telescope–it reveals objects roughly two to three times as faint. Software often struggles with such faint objects, but humans shine at pattern recognition in this kind of data, making your contributions to this search more valuable than ever. 

Another important feature of the new data is that it mostly comes from the ecliptic, the band of sky where asteroids and comets preferentially travel. The project team expects this deeper, ecliptic-focused coverage to substantially increase the number of main-belt asteroids they can recover and confirm and bring fresh waves of near-Earth asteroid candidates. 

Keep an eye out for new Bok subject sets as they are added. They’ll be a little more challenging and a lot more rewarding!

The Daily Minor Planet is a regularly updated citizen science project hosted by the Zooniverse using nightly data collected by the Catalina Sky Survey. Anyone with a laptop or smartphone can join.

Nighttime view of the white Bok telescope dome at Kitt Peak National Observatory beneath a star-filled sky. The Milky Way stretches overhead with dense star clouds and reddish nebulae visible, while the observatory sits beside a curved road on a dark hillside.
The Bok telescope stands tall under the Milky Way. Join The Daily Minor Planet project to view data from this telescope and hunt for near-Earth asteroids.
KPNO/NOIRLab/NSF/AURA/T. Slovinský

Learn More and Get Involved

The Daily Minor Planet

Discover new asteroids every day!

Share

Details

Last Updated
Mar 13, 2026
Editor
NASA Science Editorial Team

Related Terms

Explore More



from NASA https://ift.tt/AkuGxW7
at No comments:
Labels:
Subscribe to: Comments (Atom)

A Bit of Gray on an Emerald Isle

Science Earth Observatory A Bit of Gray on an Emerald Isle Earth Earth Observatory Image of the Day EO Explorer All To...