2026 August 14
Explanation: On August 12, the Moon's shadow reached out to touch our fair planet. Beginning in the Arctic Ocean, it swept along a narrow track that led the dark lunar umbra across parts of Greenland, Iceland, the Atlantic, Portugal, and northern Spain. And for a moment, denizens of Earth who found themselves with clear skies under the shadow of the Moon could witness a total solar eclipse. After dodging the weather by sea and making a landing along Rype Fjord on the Greenland east coast (at 71.07055N, 27.71252W), this hard-won snapshot was captured at 17:33:26 UTC. That's near the initial reach of clearing skies along the path of totality, so the image is likely one of the first unobstructed views of the totally eclipsed Sun. Through a break in the clouds, the stunning photo also records one of this eclipse's transient diamond rings and the magnificent solar corona emerging near the moment totality began.
2026 August 13
Explanation: On August 12th, 2026, the Moon totally eclipsed the Sun and cast its shadow across Siberia, Greenland, Iceland, Spain, and Portugal. Today’s image features two total solar eclipses viewed from Zaragoza, Spain, one over the Cathedral-Basilica of Our Lady of the Pillar and the other reflecting in the Ebro River. For a few moments, Spain saw its first major total solar eclipse since 1905. Those witnessing totality may experience a chill in the air, the quieting of birds, the confused chirps of insects, and the shared awe of many. It’s the corona’s time to shine as the Sun’s bright disk is blocked by the Moon. Among other reasons to study eclipses, they help scientists understand why the corona is millions of degrees hotter than the Sun’s surface. Enthusiastic citizens can contribute to these studies by recording how wildlife responds, imaging the corona, and monitoring air temperature and clouds.
2026 August 2
Explanation: What's happening to this cloud? Ice crystals in a distant cirrus cloud are acting like little floating prisms. Known informally as a fire rainbow for its flame-like appearance, a circumhorizon arc appears parallel to the horizon. For a circumhorizontal arc to be visible, the Sun must be at least 58 degrees high in a sky where cirrus clouds present below -- in this case cirrus fibratus. The numerous, flat, hexagonal ice-crystals that compose the cirrus cloud must be aligned horizontally to properly refract sunlight in a collectively similar manner. Therefore, circumhorizontal arcs are somewhat unusual to see. The featured fire rainbow was photographed in 2021 near North Fork Mountain in West Virginia, USA.
2026 August 9
Explanation: Have you contemplated your home star recently? Featured here, a Sun partially eclipsed on the top left by the Moon is also seen eclipsed by earthlings contemplating the eclipse below. This spectacular menagerie of silhouettes was taken in 2012 from the Glen Canyon National Recreation Area near Page, Arizona, USA, where park rangers and astronomers expounded on the unusual event to interested gatherers. Also, faintly visible on the Sun's disk, just to the lower right of the dark Moon's disk, is a group of sunspots. A new solar eclipse will occur this week and give many people in northern North America, Europe, and northwestern Africa a new chance to contemplate a partially eclipsed Sun. A thin swath of Earth through Greenland and Spain will further experience a total solar eclipse. An open question is whether any meteors from the peaking Perseids will be visible during totality.
2026 August 6
Explanation: What does the new sharpest image of our Sun show? Instability. To be clear, a certain kind of interactive process called the Kelvin-Helmholtz instability (KHI). This instability can create waves and swirls when two streams flow past each other -- in this case variable streams of solar magnetic plasma. Long hypothesized to occur on the Sun's surface, KHI streaks and swirls were confirmed in just-released dramatic high-resolution images taken recently by the Inouye Solar Telescope in Hawaii, USA. The featured false-yellow image, actually taken in deep blue, is the highest resolution image yet of the Sun in visible light. It spans about the radius of the Earth, but its finest details are city sized. Visible are several smooth tops of changing solar granules, while the edges of the flower-like structures have been found to harbor multiple KHI swirls. Future research may investigate how the KHI helps move energy, magnetic fields, and may even heat the surrounding solar corona.
2026 August 4
Explanation: What causes unusual knots of gas and dust in planetary nebulas? Seen also in the Ring Nebula, the Dumbbell Nebula and NGC 2392, the knots' existence was not initially predicted, and their origins are still not well understood. Pictured here is a fascinating image of part of the Helix Nebula by the James Webb Space Telescope showing tremendous detail in infrared light. The cometary knots have masses similar to the Earth but have sizes typically several times the orbit of Pluto. One hypothesis for the fragmentation and evolution of the knots includes existing gas being driven out by a less dense but highly energetic stellar wind of the central evolving star. The Helix Nebula is one of the closest examples of a planetary nebula created at the end of the life of a Sun-like star. Given a technical designation of NGC 7293, the Helix Nebula lies about 650 light-years away towards the constellation of Water Carrier (Aquarius).
La Galathée yéti (Kiwa hirsuta) ou crabe yéti est un crabe très particulier. Elle a été trouvée au niveau des sites hydrothermaux de la dors...
