Astronomy - CG 30: COMETARY GLOBULES

2026 April 28

CG 30: Cometary Globules
Image Credit & Copyright: Marcelo Salemme

Explanation: They're like mountain peaks, but they are forming stars. Bright-rimmed, flowing shapes gather near the center of this rich starfield toward the borders of the nautical southern constellations Puppis and Vela. Composed of interstellar gas and dust, the grouping of light-year sized cometary globules is about 1300 light-years distant. Energetic ultraviolet light from nearby hot stars has molded the globules and ionized their bright rims. The globules also stream away from the Vela supernova remnant which may have influenced their swept-back shapes. Within them, cores of cold gas and dust are likely collapsing to form low mass stars whose formation will ultimately cause the globules to disperse. In fact, cometary globule CG 30 (upper right in the group) sports a small reddish glow inside its head, a telltale sign of energetic jets from a star in the early stages of formation. 

Santé/Médecine - LES SYMPTOMES DE LA FIBROMYALGIE: 4. UNE FATIGUE PERSISTANTE (6/12)

Très fréquemment, la fibromyalgie cause une fatigue persistante, et ce, dès le réveil. L’intensité varie d’une personne à l’autre. Elle oscille entre fatigue légère et sensation d’épuisement, comme celle que l’on ressent avec la grippe. La fatigue peut être ressentie au moindre effort et vider la personne de son énergie. Lorsque c’est le cas, c’est l’épuisement total : À ce moment là, la personne se sent incapable de faire quoi que ce soit.

CommentEconomiser

Astronomy - CG 4: THE GLOBULE AND THE GALAXY

 2026 March 11

CG 4: The Globule and the Galaxy
Image Credit & Copyright: William Vrbasso
Text: Cecilia Chirenti (NASA GSFC, UMCP, CRESST II)

Explanation: Is this a cosmic monster ready to devour an unsuspecting galaxy? Thankfully, that is not the case. The red “monster” shown in the featured image is Cometary Globule CG 4, 1,300 light-years away in the Constellation Puppis. CG 4 is a molecular cloud, where hydrogen becomes cold enough to form molecules that can be brought together by gravity to create stars. The shape of CG 4 resembles that of a comet, but its head is 1.5 light-year in diameter and its tail is 8 light-years long; for comparison, the distance from the Earth to the sun is only 8 light-minutes. Astronomers believe that the tail of a cometary globule could have been shaped by a nearby supernova explosion or by irradiation from hot, massive stars. Indeed, CG 4 and other nearby globules point away from the Vela Supernova Remnant, at the center of the Gum Nebula. The edge-on spiral galaxy, ESO 257-19, is more than a hundred million light-years beyond CG 4, and is completely safe from the “monster”.

Astronomy - MYSTIC MOUNTAIN MONSTER BEING DESTROYED

 2026 April 26

Mystic Mountain Monster being Destroyed
Image Credit: Hubble, NASA, ESA; Processing & License: Judy Schmidt

Explanation: Inside the head of this interstellar monster is a star that is slowly destroying it. The huge monster, actually an inanimate series of pillars of gas and dust, measures light years in length. The in-head star is not itself visible through the opaque interstellar dust but is bursting out partly by ejecting opposing beams of energetic particles called Herbig-Haro jets. Located about 7,500 light years away in the Carina Nebula and known informally as Mystic Mountain, the appearance of these pillars is dominated by dark dust even though they are composed mostly of clear hydrogen gas. The featured image was taken with the Hubble Space Telescope. All over these pillars, the energetic light and winds from massive newly formed stars are evaporating and dispersing the dusty stellar nurseries in which they formed. Within a few million years, the head of this giant, as well as most of its body, will have been completely evaporated by internal and surrounding stars.

Santé/Médecine - LES SYMPTOMES DE LA FIBROMYALGIE: 3. - DES RAIDEURS MATINALES (5/12)

Beaucoup de personnes atteintes de fibromyalgies souffrent de raideurs. Généralement, elles sont plus intenses le matin, au réveil. Mais on peut aussi les ressentir en journée, si l’on reste trop longtemps dans la même position.

Au toucher, les muscles deviennent plus durs et plus sensibles. Souvent, les raideurs provoquent aussi des spasmes. C'est quoi des spasmes ? Ce sont des contractions musculaires douloureuses.

CommentEconomiser

Astronomy - THE PERSISTENCE OF SUNLIGHT

 2026 April 25

The Persistence of Sunlight
Image Credit & Copyright: Lorenzo Busilacchi

Explanation: This seaside sunset offered a surreal experience, captured in a sea and skyscape from the west coast of Sardinia, Italy, planet Earth. The Daliesque scene is a composition of sequential exposures made with a camera and long telephoto lens. The Sun is not melting, though. Its shifting and fluid appearance as it nears the horizon is caused as refraction along the line of sight changes and creates distorted images or mirages of the reddened solar disk. The changes in atmospheric refraction correspond to atmospheric layers with sharply different temperatures and densities. Another famous but fleeting effect of atmospheric refraction produced by a long sight-line to the setting (or rising) Sun is often called the green flash.

Astronomy - YOUNG MOON AND SISTER STARS

2026 April 24

Young Moon and Sister Stars
Image Credit & Copyright: Giorgia Hofer

Explanation: Sunlit arms of a crescent moon seem to embrace the faint lunar night side in this dramatic celestial scene from planet Earth. The single telephoto exposure tracking the sky was captured on the night of April 19, when a two day old Moon was near perigee in its elliptical orbit. On that date, the young Moon was also close on the sky to the lovely Pleiades Star Cluster. With the moonlight dimmed by clouds the Pleiades sister stars gather below the Moon's bright crescent, seen through a faint but colorful lunar corona. The lunar night side is illuminated by earthshine, sunlight reflected from the Earth itself. The Moon's ashen glow, also known as the "old moon in the young moon's arms", tends to be brighter in the northern hemisphere spring. And for now, the Moon's orbit takes it near the Pleiades stars each month in planet Earth's sky, though their close conjunctions are easiest to see when the Moon is near a crescent phase. 

Santé/Médecine - LES SYMPTOMES DE LA FIBROMYALGIE: 2. UNE GRANDE SENSIBILITE A LA DOULEUR - (4/12)

La fibromyalgie peut aussi augmenter la sensibilité à la douleur. Dans les cas les plus sévères, un simple toucher ou même un effleurement provoque des douleurs sur tout le corps. Les médecins définissent ce symptôme par les termes suivants :

 

- l’hyperalgésie pour décrire une sensibilité excessive à la douleur. 

- l’allodynie, pour décrire une douleur déclenchée par quelque chose qui normalement ne fait pas mal. Un effleurement de la peau, par exemple.

Et ce n’est pas tout. En plus du toucher, on peut aussi avoir une plus grande sensibilité : 

- aux odeurs, 

- aux bruits, 

- à certains aliments, 

- à la lumière et 

- aux changements de température. 

Souvent, s’exposer aux choses auxquelles on a une grande sensibilité peut aggraver les autres symptômes de la fibromyalgie.

CommentEconomiser

Astronomy - LARGE SCALE STRUCTURE OF THE UNIVERSE

 2026 April 23

Large Scale Structure of the Universe
Image Credit: Claire Lamman/DESI collaboration
Text: Cecilia Chirenti (NASA GSFC, UMCP, CRESST II)

Explanation: This is a map of the universe. The Dark Energy Spectroscopic Instrument (DESI) at Kitt Peak National Observatory, Arizona, has finished its five-year survey. It observed more than 47 million galaxies and quasars and created a 3D map centered on the Earth. Today's featured image shows a thin slice of these data: the black gaps indicate where our Galaxy obscures distant objects. The feathery web in the inset shows the large scale structure of the universe. Light of the most distant galaxies shown here travelled for 11 billion years to reach the Earth. Galaxies cluster throughout cosmic history under the competing influences of gravity and dark energy, responsible for the accelerated expansion of the universe. Analysis of early DESI results hinted at the possibility that dark energy, described as a cosmological constant by Albert Einstein, may not be constant after all. But we still have to wait for the analysis of the now complete dataset. The nature of dark energy is the biggest mystery of cosmology.

Astronomy - EARTHSET WITH AN IPHONE

 2026 April 22

Earthset with an iPhone
Video Credit: NASA, Reid Wiseman
Text: Keighley Rockcliffe (NASA GSFC, UMBC CSST, CRESST II)

Explanation: What does it mean for the Earth to set? Artemis II Commander Reid Wiseman gave us another spectacular view of Earth from their historic flyby of the Moon. Commander Wiseman's video, taken with an iPhone at 8x zoom, shows our entire planet gradually blocked from view by the Moon. On the Earth, the 24-hour planetary rotation causes the Sun to set below your horizon every night. However, on Artemis II the Earthset was caused not by the Moon’s rotation but by the spacecraft moving behind the Moon (at about 55 seconds in this video). Once rare, views of Earth are now taken many times a day from many spacecraft, including NASA’s SWOT (Surface Water and Ocean Topography) satellite tracking freshwater resources and USGS Landsat 8 and 9 satellites supporting water management for farmers, for example. Space agencies around our home planet now work together to provide unique and ever-improving views of our Earth.