Public Posts

NASA Astronomy Picture of the Day:

One of the all-time historic skyscapes occured in July 1054, when the Crab Supernova blazed into the dawn sky. Chinese court astrologers first saw the Guest Star on the morning of 4 July 1054 next to the star Tianguan (now cataloged as Zeta Tauri). The supernova peaked in late July 1054 a bit brighter than Venus, and was visible in the daytime for 23 days. The Guest Star was so bright that every culture around the world inevitably discovered the supernova independently, although only nine reports survive, including those from China, Japan, and Constantinople. This iPhone picture is from Signal Hill near Tucson on the morning of 26 July 2025, faithfully re-creates the year 1054 Dawn of the Crab, showing the sky as seen by Hohokam peoples. The planet Venus, as a stand-in for the supernova, is close to the position of what is now the Crab Nebula supernova remnant. Step outside on a summer dawn with bright Venus, and ask yourself "What would you have thought in ancient times when suddenly seeing the Dawn of the Crab?"

The Comet NEOWISE on 15 August 2020 from Konská, Žilina District, Slovakia. It resulted the brightest comet in the northern hemisphere since Comet Hale–Bopp in 1997, but it would have been exceeded in brightness by comet Comet Tsuchinshan–ATLAS in 2024.

Palonitor, CC BY-SA 4.0, via Wikimedia Commons. View source.

NASA Astronomy Picture of the Day:

This stunning starfield spans about three full moons (1.5 degrees) across the heroic northern constellation of Perseus. It holds the famous pair of open star clusters, h and Chi Persei. Also cataloged as NGC 869 (right) and NGC 884, both clusters are about 7,000 light-years away and contain stars much younger and hotter than the Sun. Separated by only a few hundred light-years, the clusters are both 13 million years young based on the ages of their individual stars, evidence that both clusters were likely a product of the same star-forming region. Always a rewarding sight in binoculars or small telescopes, the Double Cluster is even visible to the unaided eye from dark locations.

Photo by Ron Brecher

Zernez, Wildenberg Castle in Zernez. Garden shed in the inner garden.

Agnes Monkelbaan, CC BY-SA 4.0, via Wikimedia Commons. View source.

NASA Astronomy Picture of the Day:

What's that green streak in front of the Andromeda galaxy? A meteor. While photographing the Andromeda galaxy in 2016, near the peak of the Perseid Meteor Shower, a small pebble from deep space crossed right in front of our Milky Way Galaxy's far-distant companion. The small meteor took only a fraction of a second to pass through this 10-degree field. The meteor flared several times while braking violently upon entering Earth's atmosphere. The green color was created, at least in part, by the meteor's gas glowing as it vaporized. Although the exposure was timed to catch a Perseid meteor, the orientation of the imaged streak seems a better match to a meteor from the Southern Delta Aquariids, a meteor shower that peaked a few weeks earlier. Not coincidentally, the Perseid Meteor Shower peaks next week, although this year the meteors will have to outshine a sky brightened by a nearly full moon.

Photo by Fritz Helmut Hemmerich

Bunker 26 in the Dülmen-Visbeck special ammunition depot, Dernekamp hamlet, Kirchspiel, Dülmen, North Rhine-Westphalia, Germany.

Dietmar Rabich, CC BY-SA 4.0, via Wikimedia Commons. View source.

NASA Astronomy Picture of the Day:

Why is this nebula so complex? The Webb Space Telescope has imaged a nebula in great detail that is thought to have emerged from a Sun-like star. NGC 6072 has been resolved into one of the more unusual and complex examples of planetary nebula. The featured image is in infrared light with the red color highlighting cool hydrogen gas. Study of previous images of NGC 6072 indicated several likely outflows and two disks inside the jumbled gas, while the new Webb image resolves new features likely including one disk's edge protruding on the central left. A leading origin hypothesis holds that the nebula's complexity is caused or enhanced by multiple outbursts from a star in a multi-star system near the center.

View from Okrążek rock in Piekary towards Vistula River, southern Poland. Tyniec Abbey on the right and Camaldolese Monastery on the left.

Jakub Hałun, CC BY-SA 4.0, via Wikimedia Commons. View source.