Every month, NASA Earth Observatory features a puzzling satellite image. The April 2026 puzzler appears above.
Your Challenge Identify the location shown in this satellite image. Share what clues you see, where you think it is, and what makes this place interesting or unique to you.
How to Answer Submit your response using this form and select “Puzzler Answer” as the topic. Please include your preferred name or alias.
You can keep it simple and just guess the location. Want to impress us? Tell us which satellite and instrument captured the image, which spectral bands were used, or point out a subtle detail about the geology or history of the area. If something catches your eye, or if this is your home or means something to you, we’d love to hear about it.
The Prize We can’t offer prize money or a trip to space to see Earth like satellites and astronauts do. But we can offer something almost as rewarding: puzzler bragging rights.
About a week after the challenge, we’ll post the answer at the top of this page, along with a link to an Earth Observatory Image of the Day story that explains the image in more detail. We’ll recognize the first person who correctly guesses the location, and we may also highlight readers who share especially thoughtful or interesting answers. By submitting a response, you acknowledge that your comments may be edited, excerpted, and published on this page.
Until then, zoom in, look closely, and enjoy the challenge. See you at the reveal!
NASA astronaut Jessica Meir dines on fresh Mizuna mustard greens she harvested earlier that day aboard the International Space Station.
Credits: NASA
No matter how far humanity aims to travel or how ambitious the mission, nutrition will play a key role for the crew members on distant worlds. Before planning long-term stays on the Moon, Mars, and beyond, humans must learn to grow and care for plants and other sources of nutrition like algae to keep the explorers taking part in these adventures fed.
To solve this problem, NASA and its partners are conducting research aboard the International Space Station to better understand how the space environment affects nutrition-relevant organisms. Several investigations aboard Northrop Grumman’s 24th commercial resupply mission for NASA support efforts to maintain crew diets as humanity ventures deeper into the cosmos.
Studying plant-microbe interactions
Alfalfa plants in a growth chamber with LED lights during a preflight experiment at NASA’s Kennedy Space Center in Florida.
Dr. Tom Dreschel
Certain plants have bacteria in their roots that can take nitrogen from the air and convert it into a form of food that plants can use for growth. NASA’s Veg-06 studies alfalfa (Medicago sativa), a model organism, to determine how the plant interacts with this bacterium in space. This study also examines the effects of reduced lignin, which reinforces cell walls and helps plants to grow upright against gravity. In microgravity, plants may not need lignin, and reduced levels could allow plant parts to be more easily recycled, facilitating the growth of future plant generations.
Improved algae cultivation
Preflight image of spirulina growth in plant experiment units as part of the Space Surface Spirulina investigation.
Chitose Laboratory Corporation.
Other forms of nutrition that could support crew health include spirulina (Arthorospira), a type of algae high in protein, B vitamins, and antioxidants. Spirulina also has an added benefit of converting carbon dioxide into oxygen, helping replenish a crew’s air supply. While spirulina is typically grown in water tanks, a JAXA (Japan Aerospace Exploration Agency) experiment called Space Surface Spirulina is testing a method to grow the algae on a thin-film surface. This method allows more efficient production of this high-protein food while conserving water and producing fresh oxygen aboard spacecraft.
Seed studies for better spaceflight plants
European Space Agency astronaut Tim Peake poses with arugula seed packets aboard the International Space Station during the European Space Agency-Education Payload Operation-Peake (ESA-EPO-Peake) investigation.
ESA/NASA
The ESA (European Space Agency) investigation Seed Vigour exposes seeds from several plant species to spaceflight conditions aboard the space station to determine if seed growth is affected. The research builds on a 2015 study in which arugula seeds spent six months in orbit. After returning to Earth, the seeds were distributed to schools in the United Kingdom for further study. The data contributed to a 2020 publication which found that the space-flown arugula seeds took longer to sprout and demonstrated signs of partial aging, but spaceflight did not compromise seed survival or seedling development.
This new study, flying aboard the resupply mission aims to determine whether these findings apply to other plant species and could help researchers find better ways to protect crop seeds during long-duration space missions.
Canadian Space Agency astronaut David Saint-Jacques holds a bag of thousands of tomato seeds.
CSA/NASA
The Tomatosphere 9 investigation by the CSA (Canadian Space Agency) is exposing 1.8 million tomato seeds to microgravity conditions aboard the orbiting laboratory to give students an opportunity to study how the space environment affects plant growth. After the seeds return to Earth, they will be distributed to schools across the United States and Canada, where students can plant them alongside ground controls in a blind study to compare results.
Together, these studies aboard space station deepen researchers’ understanding of nutrition in space and inform ways to better grow and maintain food sources that will keep crews healthy on future missions to the Moon, Mars, and beyond.
NASA’s Webb Redefines Dividing Line Between Planets, Stars
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NASA’s Webb Redefines Dividing Line Between Planets, Stars
Astronomers used NASA’s James Webb Space Telescope to directly image 29 Cygni b, which weighs 15 times Jupiter. They found evidence for heavy chemical elements like carbon and oxygen, which strongly suggests it formed like a planet by accretion within a protoplanetary disk.
Credits: Image: NASA, ESA, CSA, William Balmer (JHU, STScI), Laurent Pueyo (STScI); Image Processing: Alyssa Pagan (STScI)
Planets, like those in our solar system, form in a bottom-up process where small bits of rock and ice clump together and grow larger over time. But the heftier the planet, the harder it is to explain its formation that way.
Astronomers used NASA’s James Webb Space Telescope to examine 29 Cygni b, an object about 15 times as massive as Jupiter orbiting a nearby star. They found multiple lines of evidence that 29 Cygni b indeed formed from this bottom-up process, bringing new insights into how the heftiest planets come to be. A paper describing these findings published Tuesday in The Astrophysical Journal Letters.
The planet formation process is broadly understood to occur within gigantic disks of gas and dust around stars through a process called accretion. Dust gloms together into pebbles, which collide and grow larger and larger, forming protoplanets and eventually planets. The largest then collect gas to become giants like Jupiter. Since it takes more time for gas giants to form, and the disk of planet-forming material eventually evaporates and disappears, planetary systems end up with many more small planets than large planets.
In contrast, stars form when a vast cloud of gas fragments and each piece collapses under its own gravity, growing smaller and denser. A similar fragmentation process could theoretically occur within protoplanetary disks as well. That could explain why some very massive objects are found billions of miles from their host stars, in regions where the protoplanetary disk should have been too tenuous for accretion to occur.
Image: Exoplanet 29 Cygni b (NIRCam Image)
Astronomers used NASA’s James Webb Space Telescope to directly image 29 Cygni b, which weighs 15 times Jupiter. They found evidence for heavy chemical elements like carbon and oxygen, which strongly suggests it formed like a planet by accretion within a protoplanetary disk.
Image: NASA, ESA, CSA, William Balmer (JHU, STScI), Laurent Pueyo (STScI); Image Processing: Alyssa Pagan (STScI)
29 Cygni b sits on the dividing line between what can be explained by these two different mechanisms. It weighs 15 times Jupiter and orbits its star at an average distance of 1.5 billion miles (2.4 billion kilometers), about the same as Uranus in our solar system. The research team targeted it because it could potentially result from either process.
“In computer models, it’s very easy for fragmentation in a disk to run away to much higher masses than 29 Cygni b. This is the lowest mass you could plausibly get. But at the same time, it’s about the highest mass you could get from accretion,” said lead author William Balmer of the Johns Hopkins University and the Space Telescope Science Institute, both in Baltimore.
Balmer’s observing program used Webb’s NIRCam (Near-Infrared Camera) in its coronagraphic mode to directly image 29 Cygni b. This planet was the first of four objects targeted by the program, all of which are known to weigh between 1 and 15 times as much as Jupiter. The team also required their targets to orbit within about 9 billion miles (15 billion kilometers) of their stars.
The planets were all young and still hot from their formation, ranging in temperature from about 1,000 to 1,900 degrees Fahrenheit (530 to 1,000 degrees Celsius). This would ensure their atmospheric chemistry was similar to the planets of HR 8799, whose system Balmer studied previously.
By choosing appropriate filters, the team was able to look for signs of light being absorbed by carbon dioxide (CO2) and carbon monoxide (CO), which allowed them to determine the amount of those heavier chemical elements, which astronomers collectively call metals.
They found strong evidence that 29 Cygni b is enriched in metals relative to its host star, which is similar to our Sun in its composition. Given the planet’s mass, the amount of heavy elements it contains is equivalent to about 150 Earths. This suggests that it accreted large amounts of metal-enriched solids from a protoplanetary disk.
Image: Exoplanet 29 Cygni b (Artist’s Concept)
Exoplanet 29 Cygni b, seen in this artist’s concept, is a gas giant weighing about 15 times the mass of Jupiter. Astronomers studied 29 Cygni b with NASA’s James Webb Space Telescope. They determined that it likely formed from accretion rather than disk fragmentation.
Illustration: NASA, ESA, CSA, Joseph Olmsted (STScI)
The team also used a ground-based optical telescope array called CHARA (Center for High Angular Resolution Astronomy) to determine if the planet’s orbit is aligned with the spin of the star. They confirmed that alignment, which would be expected for an object that formed from a protoplanetary disk.
“We were able to update the planet’s orbit, and also observed the host star to determine its orientation with respect to that orbit,” said Ash Messier, co-author and a graduate student at Johns Hopkins University. “We showed that the inclination of the planet is well-aligned with the spin axis of the star, which is similar to what we see for the planets of our solar system.”
“Put together, this evidence strongly suggests that 29 Cygni b formed within a protoplanetary disk through rapid accretion of metal-rich material, rather than through gas fragmentation,” said Balmer. “In other words, it formed like a planet and not like a star.”
As the team gathers data on the other three targets within their program, they plan to look for evidence of compositional differences between the lower-mass and higher-mass planets. This should provide additional insights into their formation mechanisms.
The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).
The following sections contain links to download this article’s images and videos in all available resolutions followed by related information links, media contacts, and if available, research paper and Spanish translation links.
Related Images & Videos
Exoplanet 29 Cygni b (NIRCam Image)
Astronomers used NASA’s James Webb Space Telescope to directly image 29 Cygni b, which weighs 15 times Jupiter. They found evidence for heavy chemical elements like carbon and oxygen, which strongly suggests it formed like a planet by accretion within a protoplanetary disk.
Exoplanet 29 Cygni b (Artist’s Concept)
Exoplanet 29 Cygni b, seen in this artist’s concept, is a gas giant weighing about 15 times the mass of Jupiter. Astronomers studied 29 Cygni b with NASA’s James Webb Space Telescope. They determined that it likely formed from accretion rather than disk fragmentation.
Super Typhoon Sinlaku spins over the North Pacific Ocean in this image acquired on April 13, 2026, with the VIIRS (Visible Infrared Imaging Radiometer Suite) on the Suomi NPP satellite.
NASA Earth Observatory/Michala Garrison
In mid-April 2026, a powerful typhoon bore down on the Mariana Islands in the North Pacific Ocean. The storm, Super Typhoon Sinlaku, was notable for reaching such exceptional strength so early in the year.
The VIIRS (Visible Infrared Imaging Radiometer Suite) on the Suomi NPP satellite captured this image at about 03:30 Universal Time (1:30 p.m. local time) on April 13, 2026, as Sinlaku approached the islands. At the time, the storm carried sustained winds of around 280 kilometers (175 miles) per hour. That places it as a violent typhoon—the highest intensity on the scale used by the Japan Meteorological Agency and equivalent to a category 5 storm on the Saffir-Simpson wind scale.
The storm continued along its northwest track toward the Marianas on the morning of April 14, as storm bands began to bring heavy rain to the islands of Saipan, Tinian, and Rota, according to an update from the National Weather Service. Forecasts called for typhoon conditions to affect Saipan and Tinian from April 14 into April 15 before subsiding to tropical storm conditions.
Though Super Typhoon Sinlaku occurred in the troposphere, the lowest layer of the atmosphere, it formed gravity waves that were visible much higher. The VIIRS (Visible Infrared Imaging Radiometer Suite) on the NOAA-20 satellite captured this nighttime image of the concentric waves made visible in the mesosphere by airglow.
Sinlaku is the second category 5 tropical cyclone of 2026, following Horacio, which churned over the South Indian Ocean in late February. Meteorologists note that Sinlaku is also one of only a handful of category 5 typhoons—a tropical cyclone that occurs in the Northwestern Pacific Ocean—known to have occurred so early in the year.
Meanwhile, several other storms spun over the planet’s oceans. On April 10, Tropical Cyclone Maila rotated in the opposite direction across the equator, and on April 12, Tropical Cyclone Vaianu crossed New Zealand’s North Island.
NASA Invites Media to Rollout Event for Artemis III Moon Rocket Stage
Pictured above is the top four-fifths of the SLS (Space Launch System) core stage – the section containing the liquid hydrogen tank, liquid oxygen tank, intertank, and forward skirt. NASA will roll the largest section of the agency’s SLS rocket that will launch the second crewed Artemis mission under the Artemis III mission out of NASA’s Michoud Assembly Facility on Monday, April 20.
Credit: NASA
NASA will roll the largest section of the agency’s SLS (Space Launch System) rocket, which will launch the second crewed Artemis mission, out of the agency’s Michoud Assembly Facility in New Orleans on Monday, April 20. What’s called the top four-fifths of the SLS core stage – the section containing the liquid hydrogen tank, liquid oxygen tank, intertank, and forward skirt – will be loaded on the agency’s Pegasus barge for delivery to NASA’s Kennedy Space Center in Florida.
Media will have the opportunity to capture images and video, hear remarks from agency and industry leadership, and speak with NASA subject matter experts and Artemis industry partners as crews move the rocket stage to the Pegasus barge.
This event is open to U.S. media, who must apply by Wednesday, April 15. Interested media must contact Jonathan Deal at jonathan.e.deal@nasa.gov and Craig Betbeze at craig.c.betbeze@nasa.gov. Registered media will receive confirmation and additional information about the event by email. The agency’s media credentialing policy is available online.
Once at NASA Kennedy, teams will complete the stage outfitting and vertical integration before handing the hardware over to the agency’s Exploration Ground Systems Program that will handle stacking and launch preparations. The Artemis III SLS engine section and boat-tail, which protects the engines during launch, moved from the Space Systems Processing Facility at NASA Kennedy to the Vehicle Assembly Building in July 2025. The four core stage RS-25 engines are scheduled to ship from NASA’s Stennis Space Center in Bay St. Louis, Mississippi no later than July 2026 for integration into the engine section.
The rocket stage with its four RS-25 engines will provide more than 2 million pounds of thrust to send astronauts aboard the Orion spacecraft for the Artemis III mission. Artemis III currently is scheduled for launch in 2027, following the successful Artemis II test flight mission around the Moon that concluded April 10.
Building, assembling, and transporting the core stage is a collaborative process for NASA, Boeing, the core stage lead contractor, and lead RS-25 engines contractor L3Harris Technologies. The core stage is the backbone of the SLS rocket. All five major structures for the rocket stage are manufactured at NASA Michoud. By optimizing space at NASA Kennedy and NASA Michoud for production, integration, and outfitting, NASA and industry can streamline production for a standardized SLS configuration for NASA’s Artemis program.
The Artemis III mission will launch to Earth’s orbit American astronauts in the Orion spacecraft on top of the SLS rocket to test rendezvous and docking capabilities between Orion and commercial spacecraft needed to land astronauts on the Moon in 2028. The SLS rocket is the only rocket capable of sending Orion, astronauts, and supplies to the Moon in a single launch.
Artemis III is the second crewed mission under the agency’s Artemis program, where NASA is sending astronauts on increasingly difficult missions to explore more of the Moon for scientific discovery, economic benefits, establish an enduring human presence on the lunar surface, and build on our foundation for the first crewed missions to Mars.
