
Plato and the Lunar Alps
The dark-floored, 95 kilometer wide crater Plato and sunlit peaks of the lunar Alps (Montes Alpes) are highlighted in this this sharp telescopic snapshot of the Moon's surface. While the Alps of planet Earth were uplifted over millions of years as continental plates slowly collided, the lunar Alps were likely formed by a sudden collision that created the giant impact basin known as the Mare Imbrium or Sea of Rains. The mare's generally smooth, lava-flooded floor is seen below the bordering mountain range. The prominent straight feature cutting through the mountains is the lunar Alpine Valley (Vallis Alpes). Joining the Mare Imbrium and northern Mare Frigoris (Sea of Cold) the valley extends toward the upper right, about 160 kilometers long and up to 10 kilometers wide. Of course, the large, bright lunar alpine mountain below and right of Plato crater is named Mont Blanc. Lacking an atmosphere, not to mention snow, the lunar Alps are probably not an ideal location for a winter vacation. Still, a 150 pound skier would weigh a mere 25 pounds on the Moon.
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M51: The Whirlpool Galaxy
The Whirlpool Galaxy is a classic spiral galaxy. At only 30 million light years distant and fully 60 thousand light years across, M51, also known as NGC 5194, is one of the brightest and most picturesque galaxies on the sky. The featured deep image is a digital combination of images taken in different colors over 58 hours with a telescope from Lijiang, China. Anyone with a good pair of binoculars, however, can see this Whirlpool toward the constellation of the Hunting Dogs (Canes Venatici). M51 is a spiral galaxy of type Sc and is the dominant member of a whole group of galaxies. Astronomers speculate that M51's spiral structure is primarily due to its gravitational interaction with the smaller galaxy just above it.
Read moreA Solar Eruption from SDO
What just leapt from the Sun? A towering structure of solar plasma suddenly rose from the Sun's surface and unfurled into space -- a structure so large that many Earths would easily fit within it-- marking the onset of a dramatic Coronal Mass Ejection (CME). The event was captured in striking detail in late 2024 by NASA's Solar Dynamics Observatory (SDO), whose continuous monitoring improves space weather forecasts and helps humanity better understand how solar activity affects satellites, GPS, radio communications, and power grids on Earth. The featured video blends three extreme-ultraviolet views from SDO’s Atmospheric Imaging Assembly (AIA), revealing how plasma at different temperatures surged upward as the eruption unfolded. Here, red highlights cooler, denser material lifted from the Sun’s lower atmosphere, while yellow traces hotter, million-degree coronal loops stretching outward as magnetic fields open. After the main outburst, the Sun’s magnetic fields quickly reorganize.
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Meteor Dust
What's happening to this meteor? It is shedding its outer layers as it passes through the Earth's atmosphere and heats up. The sudden high temperatures not only cause the bright glow along the dramatic streak but also melt and vaporize the meteor's component rock and ice, creating dust. Wind in the atmosphere typically blows this dust away over the next few seconds, leaving no visible trace after only a few minutes. Much of this dust will eventually settle down to the Earth. The featured image was captured in mid-December, coincident with the Geminids meteor shower. On the upper left is Sirius, the brightest star in the night sky, while in the foreground is fog-engulfed Huangshan, the Yellow Mountains of eastern China.
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M104: The Sombrero Galaxy in Infrared
This floating ring is the size of a galaxy. In fact, it is a galaxy -- or at least part of one: the photogenic Sombrero Galaxy, one of the largest galaxies in the nearby Virgo Cluster of Galaxies. The dark band of dust that obscures the mid-section of the Sombrero Galaxy in visible light actually glows brightly in infrared light. The featured image, digitally sharpened, shows the infrared glow, recently recorded by the orbiting Spitzer Space Telescope, superposed in false-color on an existing image taken by NASA's Hubble Space Telescope in visible light. The Sombrero Galaxy, also known as M104, spans about 50,000 light years and lies 28 million light years away. M104 can be seen with a small telescope in the direction of the constellation Virgo. Jigsaw Galaxy: Astronomy Puzzle of the Day
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Jupiter with the Great Red Spot
Jupiter reaches its 2026 opposition today, January 10. That puts our Solar System's most massive planet opposite the Sun and near its closest and brightest for viewing from planet Earth. In fact, captured only 3 days ago this sharp telescopic snapshot reveals excellent details of the ruling gas giant's swirling cloudtops, in light zones and dark belts girdling the rapidly rotating outer planet. Jupiter's famous, persistent anticyclonic vortex, known as the Great Red Spot, is south of the equator at the lower right. But two smaller red spots are also visible, one near the top in the northernmost zone, and one close to Jupiter's south pole. And while Jupiter's Great Red Spot is known to be shrinking, it's still about the size of the Earth itself.
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Ice Halos by Moonlight and Sunlight
Both Moon and Sun create beautiful ice halos in planet Earth's sky. In fact, the two brightest celestial beacons are each surrounded by a complex of ice halos in these photos of the sky above Chamonix-Mont-Blanc in France. The panels were recorded one night (left) and the following day at the end of December 2025. Similar ice halos appear in moonlight and sunlight because they are all formed through the geometry of flat, hexagonal ice crystals. The ice crystals reflect and refract light as they flutter in the cold atmosphere above the mountain resort. In the pictures both Moon and Sun are surrounded by a more commonly seen 22 degree circular halo. Bright and sometimes colorful patches at the intersections of the 22 degree circular halos with the indicated parselenic and parhelic arcs are also known as Moon dogs and Sun dogs. (Editor's note: Annotations updated by Marcella Pace)
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IC 342: Hidden Galaxy in Camelopardalis
Similar in size to large, bright spiral galaxies in our neighborhood, IC 342 is a mere 10 million light-years distant toward the long-necked, northern constellation Camelopardalis. A sprawling island universe, IC 342 would otherwise be a prominent galaxy in our night sky, but it is hidden from clear view and only glimpsed through the veil of stars, gas and dust clouds along the plane of our own Milky Way galaxy. Even though IC 342's light is dimmed and reddened by intervening cosmic clouds, this sharp telescopic image traces the galaxy's own obscuring dust, young star clusters, and glowing star forming regions along spiral arms that wind far from the galaxy's core. IC 342 has undergone a recent burst of star formation activity and is close enough to have influenced the evolution of the local group of galaxies and the Milky Way.
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