Photographer: Emanuele Nifosì
Summary Author: Emanuele Nifosì
The photo comparison above shows the waxing Moon at top, 99 percent full, for January 2024, and the waning Moon at bottom, also 99 percent full, for February 2024. Beyond the slight chromatic difference, due to the changing atmospheric conditions. The terminator (i.e. the line that separates the bright part from the dark part of the lunar surface) for the waxing Moon is found at the western edge (left-most), while for the waning Moon it's along the eastern edge (right-most). Therefore, when observing carefully we can notice how the Moon, which appears full in both photos, reveals different peculiarities based on the incidence of the Sun's rays:
Waxing - near the southeast margin, the Grimaldi Crater is clearly visible and defined, while the north-west craters appear blurred.
Waning: high up near the northeast margin, the Cleomedes Crater and the Mare Crisium are clearly visible.
On both photos, the light rays emerging from the Tycho Crater, in the southwest sector, and from the Copernicus and Kepler Craters, in the southeast sector, can be easily identified but perhaps have slightly greater definition in the waxing Moon (top).
Photo Details: Nikon Z8 camera; Nikkor 200-500 lens. Waxing Moon Photo: ISO 400; f/14; 1/60 second exposure; taken on January 24, 2024, 5:47 pm local time. Waning Moon Photo: ISO 200; f/18; 1/80 second exposure; taken on February 25, 2024, 11:18 pm local time.
Ragusa, Sicily, Italy Coordinates: 36,786975, 14,697012
Related Links:
The Full Moons of 2020
Geography of the Moon
Geologic Map of the Moon
Photographer: Andrea Iorio
Summary Author: Andrea Iorio
NGC 891 is a bright galaxy in the constellation Andromeda, 3.5 degrees east of the star γ Andromedae. From our perspective, it’s seen perfectly side-on, so on a short focal length telescope it appears as a long clear spindle. At higher magnifications (inset), the presence of a very bright central bulb is clearly visible as well as a dark band of interstellar dust and gas. NGC 891 is part of a group of galaxies some 30 million light years away from the Milky Way’s local group of galaxies. Image obtained on the nights of 4, 5, 6 and 7 December 2023 -- 10-hours of acquisition time.
Photo and set up details: ASI 533MC Pro astronomical camera (gain 101, offset 40, -10°C); ZWO OAG; ASI 120 mm for guiding Skywatcher 130PDS f5 telescope with 1X coma corrector; EQM-35 Pro equatorial mount. Night sky conditions equivalent to Bortle 6 (SQM 19.11).
Marino, Roma, Italy Coordinates: 41.7697883, 12.6586082
Related Links:
Two Views of the Wondrous Andromeda Galaxy
Galaxies Over Time
Photographer: Teresa Molinaro
Summary Author: Teresa Molinaro
The site called Volcanites of the Cyclops and Aci Trezza Archipelago is found along the stretch of sea in front of Aci Trezza, a fishing village known for where the author Giovanni Verga set the novel "I Malavoglia." It’s part of the Isole dei Ciclopi Marine Protected Area, a small archipelago made up of three main islets, Lachea, Faraglione Grande and Faraglione Piccolo, and of the sea stacks shown at center.
The Isole dei Ciclopi owes its name to the legend of Polyphemus and Ulyssses. According to this legend, Polyphemus threw huge boulders at Ulysses during his escape. Actually, the rocks that form the archipelago originated some five hundred thousand years ago, during the first of the four phases of Mount Etna's evolution, following the clash between the Eurasian Plate and the African Plate. This collision gave rise to a long period of underwater volcanic activity which, with the emission of basic lava gave rise to the Lachea Island and the two Faraglionis. Four types of volcanics can be found here, namely columnar basalts, those with thin prisms, hyaloclastites and pillow lavas.
Note the iridescent cloud floating high above the sea stacks. Photo taken on February 3, 2024.
Photo Details: Nikon D7500 camera; f/16; 1/320 seconds exposure; ISO 200; 18-140 mm.
Aci Trezza, Sicily, Italy Coordinates: 37.5639,15.1615
Related Links:
Sea Stacks off Aci Trezza, Italy
Etna Volcano at Night
Teresa’s Website
Photographer: Theofanis Matopoulos, International Gemini Observatory/NOIRLab/NSF/AURA/T
Summary Author: Theofanis Matopoulos
From the vantage point of Gemini North, one-half of the International Gemini Observatory atop the volcanic summit of Mauna Kea, a rainbow fragment can be seen at left. One of the five volcanoes constituting the Big Island of Hawaii, Mauna Kea rises to an elevation of 13,786 ft (4,205 m). At this elevation, tropical clouds infrequently cover the summit, but at lower altitudes, they bring with them moisture, particularly on the windward flanks.
Rainbows form at the antisolar point of the viewer when raindrops refract and reflect sunlight. The drops act as prisms, slowing and then separating the almost white sunlight into its component colors. The result is a spectacular spectrum of light — a rainbow. The bow fragment shown above is beautifully complimented by the red soil of the volcano and deep blue of the sky.
Photo taken on March 31, 2022, as part of the recent NOIRLab 2022 Photo Expedition to all the NOIRLab sites.
Mauna Kea Summit, Big Island, Hawaii Coordinates: 19.820679, -155.468024
Related Links:
Rainbow Fragment and Anticrepuscular Rays
Theofanis’ Website
Photographer: James Peirce
Summary Authors: James Peirce; Jim Foster
Comet 12P/Pons-Brooks is featured above as imaged from my Esprit 120ED telescope in the evening sky on March 8, 2024, in Skull Valley, Utah. It seems that outburst events in recent months have contributed to the fascinating tails of 12P/Pons-Brooks, including the so called horns, leading to its nickname Devil’s Comet. I have to say that this is the most dynamic and interesting comet I’ve imaged.
Though 12P/Pons-Brooks won't have its closest approach to the Sun until April 21 (parhelion date), it's currently just visible to the unaided eye in very dark skies (Bortle Scale 1-3). For Northern Hemisphere viewers, look for it approximately 20 degrees above the horizon (2-fists held at arms-length) in the western sky (approximately 290 degrees azimuth) an hour after sunset. It's easily visible through a small telescope or binoculars if you know just where to look. This comet's brightness has been rather unpredictable thus far, but if it becomes brighter during the next two weeks, Comet12P could end up putting on a fun show -- and could even be visible during the total solar eclipse on April 8 (Mexico, United States, Canada).
Photo/equipment Details: Esprit 120ED telescope on my AM5 (chonky Burlebach tripod) along with my ZWO ASI2600MC Duo camera. Software: Adobe Photoshop, Pleiades Astrophoto PixInsight.
Skull Valley, Utah Coordinates: 40.3988,-112.7205
Related Links:
Comet NEOWISE Seen from Quebec City
James’ Website
Photographer: Alessandra Masi
Summary Author: Alessandra Masi
The iridescent clouds shown above painted the late day sky spectacularly over the peaks of the Dolomites. When sunlight interacts with tiny water droplets in thin clouds (most often mid-level clouds), diffraction processes may result in iridescence. In essence, interference of sunlight around the outside of similar-sized droplets causes overlapping orders of colors, creating the pastel hues. Photo taken on January 15, 2024, at 4:30 p.m. local time.
Photo Details: Canon R6 camera; Canon 70/300 mm lens; 221 mm; ISO 100; f 13; 1/200 seconds exposure.
Cibiana di Cadore, Italy Coordinates: 46.3692, 12.2615
Related Links:
Corona and Iridescence at Giau Pass in the Dolomites
Iridescent Clouds at Sunrise over the Five Towers
Alessandra’s Website
Photographer: Gabriel Muñoz
Summary Author: Gabriel Muñoz
As viewed here seemingly perched atop the simmering Villarrica Volcano (9,341 ft or 2,847 m) in Chile, Alpha Centauri is the closest stellar system to the Sun. It's the 3rd brightest star in the night sky. Alpha Centauri is bright because it's nearby, lying approximately 4.36 light-years away in the constellation of Centaurus. Photo taken on December 28, 2023.
Photo Details: Canon RP camera; EF70/200; f4; ISO 3200; 3.2 seconds exposure.
Villarrica Volcano, Chile, Coordinates: -39.4210,-71.9396
Related Links:
Erupting Villarrica Volcano
Star Facts for Kids
Photographer: Rosario Catania
Summary Author: Rosario Catania
On the slopes of Mount Etna is a lava flow cave known as Grotta dei Tedeschi in the Immacolatelle and Micio Conti Caving Complex. It stretches for about 490 feet (150 meters) and like many caves has large fallen rocks on its floor and narrow passages, but in the larger rooms it offers a unique spectacle.
Here it's possible to observe the bare roots of the oak forest that grow on the surface and, thanks to the fracturing of the volcanic rock, over decades have extended into the depths. They penetrate the surface vault of the cave until reaching the quarry area, pushing lower and lower to capture the moisture present inside the cave, which often reaches humidity values close to saturation (80-90 percent). Nature never ceases to amaze! The photo shows the roots, microdroplets of water and fog clouds, which stand out thanks to artificial lighting.
I thank for this expedition Cinzia Lo Certo, Giovanni Sturiale and Roberto Maugeri. Photo taken on January 9, 2024.
San Gregorio di Catania, Sicily, Italy Coordinates: 37.56764, 15.1112
Related Links:
The Wonder of Roots
Rosario’s Website
Photographers: Mike Carey (top), Joli McCathran (bottom)
Summary Authors: Jim Foster; Mike Carey
Shown above is a community bench carved from the state of Maryland’s former champion white oak, known as the Linden Oak (top photo). Taken down in 2023 after it had died and was deemed a safety concern, it was at the time the biggest white oak in Maryland, standing 97 ft (30 m) tall with a crown that spread out 132 ft (40 m) -- bottom photo. It likely first sprouted in the early 1700s, well before the Declaration of Independence was written and even before George Washington was born. The Linden Oak is nicknamed the $2 million tree since the track of Washington D. C.'s Metro’s Redline was shifted slightly during its construction in 1973 to spare the tree. The estimated cost of the re-routing (in 1973) was $2 million dollars.
After it was felled, a portion of its trunk was then hauled about 1 mile (1.6 km) away to Ken-Gar Palisades Park, in the same stream valley as the Linden Oak, but with heavier foot traffic. This is where the bench was carved. Happily, the remnants of this once splendid tree didn't end up as mere splinters -- or as desks for state officials. Top photo taken in January 2024; bottom photo taken in 2018.
Kensington, Maryland Coordinates: 39.0257, -77.0764
Related Links:
Maryland’s Bicentennial Tree Project
Wye Oak Clone in Maryland
Maryland Wye Oak
Photographer: Jeanette Stafford
Summary Author: Jeanette Stafford
This photograph shows an ancient field boundary curving towards the remains of Clachtoll Broch from where the Torridonian red sandstone used in its construction was sourced. To the left of the boundary, the undulations left by previous use of the run rig agricultural system are clearly visible, and towards the upper right, the mound under excavation is Clachtoll Broch, an Iron Age round tower, constructed by dry stone walling from the local stone around 2,000 years ago.
Stoer Bay, visible beyond the broch, is of interest in particular for the Stac Fada meteorite complex. Stac Fada is a small rock pinnacle visible at low tide that was originally thought to be volcanic in origin due to the inclusion of green devitrified glass. More recent analysis discovered shocked quartz suggesting an event with extraterrestrial origins. The most likely site of such a meteorite impact has been identified as near the town of Lairg, around 31 miles (50 km) to the east. Photo taken on September 17, 2023.
Stoer Bay, Sutherland, Scotland Coordinates: 58.1984, -5.346
Related Link:
Run Rigs at Clachtoll, Scotland