ASTRONOMY - The Horsehead and Flame Nebulas

 2025 September 2

The Horsehead and Flame Nebulas
Image Credit & Copyright: Daniel Stern

Explanation: The Horsehead Nebula is one of the most famous nebulae on the sky. It is visible as the dark indentation to the orange emission nebula at the far right of the featured picture. The horse-head feature is dark because it is really an opaque dust cloud that lies in front of the bright emission nebula. Like clouds in Earth's atmosphere, this cosmic cloud has assumed a recognizable shape by chance. After many thousands of years, the internal motions of the cloud will surely alter its appearance. The emission nebula's orange color is caused by electrons recombining with protons to form hydrogen atoms. Toward the lower left of the image is the Flame Nebula, an orange-tinged nebula that also contains intricate filaments of dark dust.

ASTRONOMY - Callisto: Dirty Battered Iceball

2025 September 1

Callisto: Dirty Battered Iceball
Image Credit: NASA, JPL-Caltech, Voyager 2; Processing & License: Kevin M. Gill;

Explanation: Its surface is the most densely cratered in the Solar System -- but what's inside? Jupiter's moon Callisto is a battered ball of dirty ice that is larger than the planet Mercury. It was visited by NASA's Galileo spacecraft in the 1990s and 2000s, but the recently reprocessed featured image is from a flyby of NASA's Voyager 2 in 1979. The moon would appear darker if it weren't for the tapestry of light-colored fractured surface ice created by eons of impacts. The interior of Callisto is potentially even more interesting because therein might lie an internal layer of liquid water. This potential underground sea is a candidate to harbor life -- similar with sister moons Europa and Ganymede. Callisto is slightly larger than Luna, Earth's Moon, but because of its high ice content is slightly less massive. ESA's JUICE and NASA's Europa Clipper missions are now headed out to Jupiter to better investigate its largest moons. 

ASTRONOMY - NGC 7027: The Pillow Planetary Nebula

 2025 August 31

NGC 7027: The Pillow Planetary Nebula
Image Credit: NASA, ESA, Hubble; Processing: Delio Tolivia Cadrecha

Explanation: What created this unusual planetary nebula? Dubbed the Pillow Nebula and the Flying Carpet Nebula, NGC 7027 is one of the smallest, brightest, and most unusually shaped planetary nebulas known. Given its expansion rate, NGC 7027 first started expanding, as visible from Earth, about 600 years ago. For much of its history, the planetary nebula has been expelling shells, as seen in blue in the featured image by the Hubble Space Telescope. In modern times, though, for reasons unknown, it began ejecting gas and dust (seen in brown) in specific directions that created a new pattern that seems to have four corners. What lies at the nebula's center is unknown, with one hypothesis holding it to be a close binary star system where one star sheds gas onto an erratic disk orbiting the other star. NGC 7027, about 3,000 light years away, was first discovered in 1878 and can be seen with a standard backyard telescope toward the constellation of the Swan (Cygnus).

ASTRONOMY - A Dark Veil in Ophiuchus

 2025 August 29

A Dark Veil in Ophiuchus
Image Credit & Copyright: Katelyn Beecroft

Explanation: The diffuse hydrogen-alpha glow of emission region Sh2-27 fills this cosmic scene. The field of view spans nearly 3 degrees across the nebula-rich constellation Ophiuchus toward the central Milky Way. A Dark Veil of wispy interstellar dust clouds draped across the foreground is chiefly identified as LDN 234 and LDN 204 from the 1962 Catalog of Dark Nebulae by American astronomer Beverly Lynds. Sh2-27 itself is the large but faint HII region surrounding runaway O-type star Zeta Ophiuchi. Along with the Zeta Oph HII region, LDN 234 and LDN 204 are likely 500 or so light-years away. At that distance, this telescopic frame would be about 25 light-years wide.

ASTRONOMY - WISPIT 2b: Exoplanet Carves Gap in Birth Disk

 2025 August 27

WISPIT 2b: Exoplanet Carves Gap in Birth Disk
Image Credit: ESO, VLT, SPHERE;
Processing & Copyright: ESO, Richelle van Capelleveen (Leiden Obs.) et al.;
Text: Ogetay Kayali (MTU)

Explanation: That yellow spot -- what is it? It's a young planet outside our Solar System. The featured image from the Very Large Telescope in Chile surprisingly captures a distant scene much like our own Solar System's birth, some 4.5 billion years ago. Although we can't look into the past and see Earth's formation directly, telescopes let us watch similar processes unfolding around distant stars. At the center of this frame lies a young Sun-like star, hidden behind a coronagraph that blocks its bright glare. Surrounding the star is a bright, dusty protoplanetary disk -- the raw material of planets. Gaps and concentric rings mark where a newborn world is gathering gas and dust under its gravity, clearing the way as it orbits the star. Although astronomers have imaged disk-embedded planets before, this is the first-ever observation of an exoplanet actively carving a gap within a disk -- the earliest direct glimpse of planetary sculpting in action.

SANTé/MEDECINE - GUERISON DU CANCER - Un espoir immense - Une solution accessible pour les malades -5/7-

Histoire d'une percée 

Dire que l’histoire de la reprogrammation moléculaire a commencé timidement serait mentir. D’abord moquée, assimilée à de la science-fiction. Pourtant, l’idée de détourner le programme génétique d’une cellule malade pour la rendre saine existe depuis le début de la génétique moderne. Ce qui change ici, c’est le « live » : on ne travaille plus sur des lignées stables en éprouvette, mais sur des cellules malignes actives, enjeux de tumeurs humaines réelles. Et si l’on regarde l’industrie biomédicale, l’innovation sud-coréenne vient fort : elle a déjà donné naissance à une start-up (Biorevert, Inc.) dédiée à transformer cette découverte en solution accessible pour les malades. Les essais cliniques humains ? En perspective, mais il faudra sans doute plusieurs années pour valider l’efficacité généralisée, garantir l’absence de conséquences à long terme et, évidemment, lutter contre les pressions pharmaceutiques qui n’ont pas intérêt à saborder leurs filières. 

Quand la Corée du Sud défie la médecine occidentale

Comment la Corée du Sud en est arrivée là ? D’abord, une tradition d’audace technologique, une culture de la médecine personnalisée et un système de soins qui ose le sur-mesure. Les succès récents de la thérapie CAR-T – où l’on modifie les cellules T du patient pour mieux cibler la tumeur – avaient déjà ouvert la porte aux traitements « intelligents ». Mais la reprogrammation cellulaire va encore plus loin : elle vise à réparer le vivant, pas à l’éliminer. N’en déplaise aux industriels occidentaux, le laboratoire du KAIST multiplie les publications, attire les capitaux, et s’entoure d’une équipe hybride où se croisent biologistes, ingénieurs, cliniciens. Ce n’est plus un « petit pays » qui tatônne en périphérie : c’est un pôle majeur de la bio-informatique appliquée à la médecine.

©Adobe Stock

ASTRONOMY - A Leaky Solar Prominence

 2025 August 26

A Leaky Solar Prominence

Video Credit & Copyright: Andrea Girones

Explanation: What's hovering above the Sun? A solar prominence. A prominence is a crest of hot gas expelled from the Sun's surface that is held aloft by the Sun's magnetic field. Prominences can last for days, can suddenly explode into space, or just fall back to the Sun. What decides a prominence's fate is how the Sun's complex magnetic field changes -- the field's direction can act like an offramp for trapped solar particles. The 3-second (repeating) time-lapse featured video was captured earlier this month from Ottawa, Ontario, Canada. It shows the development of a larger-than-Earth prominence as it appears to leak solar plasma back to the Sun, over the course of an hour. What is unusual is that the prominence appears to hover -- more simple and typical prominences form magnetic loops that connect back to the surface. Many hours after this video ended, the hovering prominence disintegrated back into the Sun.

ASTRONOMY - The Meteor and the Star Cluster

 2025 August 25

The Meteor and the Star Cluster
Image Credit & Copyright: Yousif Alqasimi & Essa Al Jasmi

Explanation: Sometimes even the sky surprises you. To see more stars and faint nebulosity in the Pleiades star cluster (M45), long exposures are made. Many times, less interesting items appear on the exposures that were not intended -- but later edited out. These include stuck pixels, cosmic ray hits, frames with bright clouds or Earth's Moon, airplane trails, lens flares, faint satellite trails, and even insect trails. Sometimes, though, something really interesting is caught by chance. That was just the case a few weeks ago in al-Ula, Saudi Arabia when a bright meteor streaked across during an hour-long exposure of the Pleiades. Along with the famous bright blue stars, less famous and less bright blue stars, and blue-reflecting dust surrounding the star cluster, the fast rock fragment created a distinctive green glow, likely due to vaporized metals.

ASTRONOMY - The Spinning Pulsar of the Crab Nebula

 2025 August 24

The Spinning Pulsar of the Crab Nebula
Image Credit: NASA: X-ray: Chandra (CXC), Optical: Hubble (STScI), Infrared: Spitzer (JPL-Caltech)

Explanation: At the core of the Crab Nebula lies a city-sized, magnetized neutron star spinning 30 times a second. Known as the Crab Pulsar, it is the bright spot in the center of the gaseous swirl at the nebula's core. About twelve light-years across, the spectacular picture frames the glowing gas, cavities and swirling filaments near the Crab Nebula's center. The featured picture combines visible light from the Hubble Space Telescope in purple, X-ray light from the Chandra X-ray Observatory in blue, and infrared light from the Spitzer Space Telescope in red. Like a cosmic dynamo, the Crab pulsar powers the emission from the nebula, driving a shock wave through surrounding material and accelerating the spiraling electrons. With more mass than the Sun and the density of an atomic nucleus,the spinning pulsar is the collapsed core of a massive star that exploded. The outer parts of the Crab Nebula are the expanding remnants of the star's component gases. The supernova explosion was witnessed on planet Earth in the year 1054.

ASTRONOMY - Fishing for the Moon

 2025 August 23

Fishing for the Moon
Image Credit & Copyright: Marco Bellelli

Explanation: How big is planet Earth's Moon? Compared to other moons of the Solar System, it's number 5 on the largest to smallest ranked list, following Jupiter's moon Ganymede, Saturn's moon Titan, and Jovian moons Callisto and Io. Continuing the list, the Moon comes before Jupiter's Europa and Neptune's Triton. It's also larger than dwarf planets Pluto and Eris. With a diameter of 3,475 kilometers the Moon is about 1/4 the size of Earth though, and that does make it the largest moon when compared to the size of its parent Solar System planet. Of course in this serene, twilight sea and skyscape, August's rising Full Moon still appears small enough to be caught in the nets of an ancient fishing rig. The telephoto snapshot was taken along the Italian Costa dei Trabocchi, on the Adriatic Sea.