Forecasters from NOAA, the European Centre for Medium-Range Weather Forecasts and several research groups report growing confidence that El Niño will develop by the Northern Hemisphere summer of 2026 and could strengthen into a very strong or “super” event. Consensus models put the probability of El Niño conditions in summer well above 80–90 percent; the likelihood of the Niño-3.4 index crossing the informal +2.0°C “super” threshold varies across ensembles. NOAA’s operational outlook and research models point to rapidly rising subsurface heat in the equatorial Pacific and favorable westerly wind anomalies, while some ECMWF and experimental GFDL members project extreme anomalies (in some runs up to +3.0°C). A strong El Niño would likely amplify global temperatures, raise heatwave, drought and wildfire risks in places such as Australia, Southeast Asia and the Amazon, and increase flooding risk in parts of South America, East Africa and the southern United States. Tropical cyclone patterns are also expected to shift. Scientists caution that spring predictability limits and model spread leave uncertainty over peak strength and regional fingerprints; agencies will continue monthly monitoring as the situation evolves through 2026–27.

NASA on May 26, 2026 began buying the hardware it says is needed to lay groundwork for a sustained human presence on the Moon, awarding roughly $900 million to $1 billion in task orders to U.S. commercial firms. Under the Lunar Terrain Vehicle Services (LTVS) program the agency gave Astrolab about $219 million and Lunar Outpost roughly $220 million to develop competing crewed/autonomous rovers (Astrolab’s CLV-1 and Lunar Outpost’s Pegasus) intended to operate at the lunar south pole with range requirements of about 125 miles and delivery targeted for 2028. Blue Origin received a Commercial Lunar Payload Services (CLPS) cargo task order valued at about $188 million with options worth roughly $280 million to deliver infrastructure, and Firefly Aerospace and other partners were tapped to support drone and delivery work. NASA said three iterative uncrewed “Moon Base” missions and a series of cargo deliveries are planned this year to begin emplacement of rovers, drones and science payloads near permanently shadowed regions where water ice and near-constant sunlight make long-duration operations possible.

China’s Shenzhou 21 crew safely returned to Earth on May 29, touching down at the Dongfeng landing site in Inner Mongolia after a 210-day stay aboard the Tiangong space station — the longest single Chinese crewed mission to date. Mission commander Zhang Lu, flight engineer Wu Fei and payload specialist Zhang Hongzhang completed three spacewalks and a programme of experiments in microgravity, materials science, life sciences and aerospace medicine. The trio returned in a different capsule than the one that launched them after a debris-related crack was found in the Shenzhou 20 vehicle; China launched an uncrewed replacement (Shenzhou 22) in November that later brought the Shenzhou 21 crew home. The handover to the Shenzhou 23 team, which arrived on May 24, was completed ahead of one crew member from that mission slated to remain aboard Tiangong for a year. Zhang Lu now holds a Chinese record of seven spacewalks across missions.

Blue Origin’s 98-metre New Glenn rocket exploded in a massive fireball during a hot-fire engine test at Cape Canaveral Space Force Station on the night of May 28, 2026. Video shows the vehicle erupting and parts of Launch Complex 36 sustaining heavy damage; authorities said no personnel were injured and all were accounted for. The rocket was being prepared for a June mission to deploy 48 Amazon Leo broadband satellites, which were not onboard at the time. The Federal Aviation Administration and U.S. Space Force are aware and Blue Origin and NASA have launched an investigation. The incident comes days after NASA awarded Blue Origin contracts tied to Artemis lunar missions and surface rovers, and follows earlier New Glenn flight anomalies that prompted a recent FAA probe. Blue Origin warned debris could wash ashore and advised the public not to handle any wreckage. Company founder Jeff Bezos and NASA administrator Jared Isaacman pledged a thorough review; Elon Musk and other industry figures responded publicly. Initial analysis points to a first-stage area near the BE-4 engines but the root cause remains unknown.

A rare ‘blue micromoon’ — the second full moon in May that also occurs near lunar apogee — will be visible across much of the globe on the night of May 30 into May 31, 2026. The moon reaches peak illumination at 4:45 a.m. EDT (08:45 GMT) on May 31 and, because it is almost at its farthest orbital point, will be the smallest full moon of 2026. Observers are expecting an apparent shrinkage of roughly 6% in diameter and a dimming near 10% compared with an average full moon; the lunar distance at fullness is about 252,360 miles (≈406,000 km). Skywatchers in many regions can view the event at moonrise around dusk (local times vary). Southern hemisphere viewers in places such as Argentina, Chile, New Zealand and eastern Australia may also witness the moon occulting the bright red star Antares for a short interval. Several outlets and the Virtual Telescope Project are streaming the event, and photographers and amateur astronomers are planning targeted observations during moonrise and the hours around peak fullness.

A multinational team led by researchers at the Max Planck Institute of Animal Behavior and the University of Bonn reports that homing pigeons may use iron-laden immune cells in their livers as a magnetic compass. Published May 28 in Science, the study found millions of ferritin-rich macrophages clustered near nerve fibers in pigeon livers. In behavioural trials, 34 trained pigeons were taken 19 kilometres from their home and released on overcast days after half the birds received a treatment that transiently depletes liver macrophages. Birds with intact macrophages homed in roughly 70 minutes; treated birds became disoriented and did not reliably return until sunlight reappeared. The work complements earlier hypotheses involving eye proteins or beak magnetite by identifying a different, unexpected tissue and offers a mechanistic link—iron-filled immune cells—that could transduce magnetic information to the nervous system. Authors note important gaps remain, including how macrophage signals reach the brain and whether other species share the same system.