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25/10/2023

ASTRONOMY - Gone in 60 Seconds: A Green Flash Sunset

 2023 October 25

Gone in 60 Seconds: A Green Flash Sunset
Video Credit & Copyright: Tengyu Cai

Explanation: In 60 seconds, this setting Sun will turn green. Actually, the top of the Sun already appears not only green, but wavey -- along with all of its edges. The Sun itself is unchanged -- both effects are caused by looking along hot and cold layers in Earth's atmosphere. The unusual color is known as a green flash and occurs because these atmospheric layers not only shift background images but disperse colors into slightly different directions, like a prism. The featured video was captured earlier this month off the coast of HawaiiUSA. After waiting those 60 seconds, at the video's end, the upper part of the Sun seems to hover alone in space, while turning not only green, but blue. Then suddenly, the Sun appears to shrink to nothing -- only to return tomorrow.

24/10/2023

SANTE/MEDECINE - (3/11) : Quand les sourcils retrécissent

Maux de tête, toux ou nez qui coule ? Ce sont des symptômes que nous connaissons tous et que nous pouvons tous interpréter. Mais que se passe-t-il quand vous perdez du poil aux sourcils ?

Les sourcils qui rétrécissent

Si vous perdez des poils aux extrémités externes de vos sourcils, il y a de quoi vous inquiéter. C’est peut-être un signe d’hypothyroïdie. Elle peut néanmoins être détectée par un test sanguin et traitée assez facilement.

Lastucerie

ASTRONOMY - Arp 87: Merging Galaxies from Hubble

 2023 October 24

Three large galaxies are shown, the rightmost 
two in collision. The galaxy on the far right is a large
spiral galaxy with one arm connected to an unusual 
polar galaxy on the left. The smaller galaxy on the far
left is thought to be far in the background.
Please see the explanation for more detailed information.

Arp 87: Merging Galaxies from Hubble
Image Credit: NASAESAHubble; Processing: Harshwardhan Pathak

Explanation: This dance is to the death. As these two large galaxies duel, a cosmic bridge of stars, gas, and dust currently stretches over 75,000 light-years and joins them. The bridge itself is strong evidence that these two immense star systems have passed close to each other and experienced violent tides induced by mutual gravity. As further evidence, the face-on spiral galaxy on the right, also known as NGC 3808A, exhibits many young blue star clusters produced in a burst of star formation. The twisted edge-on spiral on the left (NGC 3808B) seems to be wrapped in the material bridging the galaxies and surrounded by a curious polar ring. Together, the system is known as Arp 87. While such interactions are drawn out over billions of years, repeated close passages will ultimately create one merged galaxy. Although this scenario does look unusual, galactic mergers are thought to be common, with Arp 87 representing a stage in this inevitable process. The Arp 87 dancing pair are about 300 million light-years distant toward the constellation of the Lion (Leo). The prominent edge-on spiral galaxy at the far left appears to be a more distant background galaxy and not involved in the on-going merger.

23/10/2023

SANTE/MEDECINE - (2/11) - Les cheveux gris avant 40 ans

Maux de tête, toux ou nez qui coule ? Ce sont des symptômes que nous connaissons tous et que nous pouvons tous interpréter. Mais que se passe-t-il quand on a soudainement beaucoup de cheveux gris ? Notre corps nous envoie de nombreux signaux qui nous permettent de détecter certaines maladies.

Les cheveux gris avant 40 ans

Les cheveux gris apparaissent plus tôt chez certaines personne que chez d’autres, souvent pour des raisons génétiques. Mais avoir des cheveux gris quand on a trente ans peut aussi être le signe que quelque chose ne va pas, surtout si vous êtes le seul à avoir ce genre de problèmes dans la famille. Dans ce cas, cela peut être un signe de « suracidification » de l’organisme ou de diabète.

L'astucerie

ASTRONOMY - Moon Io from Spacecraft Juno

 2023 October 23

Jupiter's moon Io is shown as photogaphred recently
by NASA's passing Juno spacecraft. The moon is nearly half-
lit by the distant Sun and shows a complex surface including
the colors yellow, orange, and dark brown. Near the top, the
plume of an active volcano can be seen.
Please see the explanation for more detailed information.

Moon Io from Spacecraft Juno
Image Credit: NASAJPL-CaltechSwRIMSSS; Processing & Copyright: Ted Stryk & Fernando García Navarro

Explanation: There goes another one! Volcanoes on Jupiter's moon Io keep erupting. To investigate, NASA's robotic Juno spacecraft has begun a series of visits to this very strange moon. Io is about the size of Earth's moon, but because of gravitational flexing by Jupiter and other moons, Io's interior gets heated and its surface has become covered with volcanoes. The featured image is from last week's flyby, passing within 12,000 kilometers above the dangerously active world. The surface of Io is covered with sulfur and frozen sulfur dioxide, making it appear yellow, orange and brown. As hoped, Juno flew by just as a volcano was erupting -- with its faint plume visible near the top of the featured image. Studying Io's volcanoes and plumes helps humanity better understand how Jupiter's complex system of moons, rings, and auroras interact. Juno is scheduled to make two flybys of Io during the coming months that are almost 10 times closer: one in December and another in February 2024.

22/10/2023

SANTE/MEDECINE - (1/11) : La maladie bronzée

Maux de tête, toux ou nez qui coule ? Ce sont des symptômes que nous connaissons tous et que nous pouvons tous interpréter. Mais que se passe-t-il quand notre peau devient plus foncée sans être exposée au soleil ? Notre corps nous envoie de nombreux signaux qui nous permettent de détecter certaines maladies.
Voici des signaux d’alarme à prendre au sérieux, aussi insignifiants qu’ils puissent paraître.

Une peau qui bronze sans soleil

Si votre peau devient de plus en plus foncée, et ce sans être exposée au soleil, vous devriez consulter un médecin. Ce pourrait être la maladie d’Addison, ou « maladie bronzée ». La maladie entraîne un assombrissement de la peau et une fatigue chronique. Cependant, il existe des traitements permettant de soulager ces symptômes.

Lastucerie

ASTRONOMY - Ghost Aurora over Canada

 2023 October 22

A landscape is pictured with snow and a line of evergreen
trees. In the sky is a field of stars but also notable
green aurora. The largest aurora appears similar in form
to a Halloween ghost,
Please see the explanation for more detailed information.

Ghost Aurora over Canada
Image Credit & Copyright: Yuichi TakasakaTWAN

Explanation: What does this aurora look like to you? While braving the cold to watch the skies above northern Canada early one morning in 2013, a most unusual aurora appeared. The aurora definitely appeared to be shaped like something, but what? Two ghostly possibilities recorded by the astrophotographer were "witch" and "goddess of dawn", but please feel free to suggest your own Halloween-enhanced impressions. Regardless of fantastical pareidolic interpretations, the pictured aurora had a typical green color and was surely caused by the scientifically commonplace action of high-energy particles from space interacting with oxygen in Earth's upper atmosphere. In the image foreground, at the bottom, is a frozen Alexandra Falls, while evergreen trees cross the middle.

21/10/2023

ASTRONOMY - Quarter Moons

 023 October 21

See Explanation.  Clicking on the picture will download the highest resolution version available.

Quarter Moons
Image Credit & Copyright: Marcella Giulia Pace

Explanation: Half way between New Moon and Full Moon is the Moon's first quarter phase. That's a quarter of the way around its moonthly orbit. At the first quarter phase, half the Moon's visible side is illuminated by sunlight. For the Moon's third quarter phase, half way between Full Moon and New Moon, sunlight illuminates the other half of the visible lunar disk. At both first and third quarter phases, the terminator, or shadow line separating the lunar night and day, runs down the middle. Near the terminator, long shadows bring lunar craters and mountains in to sharp relief, making the quarter phases a good time to observe the Moon. But in case you missed some, all the quarter phases of the Moon and their calendar dates during 2022 can be found in this well-planned array of telephoto images. Of course, you can observe a first quarter Moon tonight.

20/10/2023

SANTE/MEDECINE - Le CBD et le Sommeil (3/3)

Les avantages du CBD sous forme de tisane

Le principal atout de l’infusion de CBD est son goût agréable puisque sous d’autres aspects la saveur peut sembler amer chez certains consommateurs. D’ailleurs, la plante de chanvre est souvent couplée avec d’autres plantes reconnues pour favoriser la détente et la relaxation, ce qui aurait pour effet de décupler les bénéfices. On pense notamment à la verveine qui aide à lutter contre l’anxiété, à la camomille qui a des vertus apaisantes ou encore au tilleul qui facilite l’endormissement. Les infusions aromatisées (aux fruits ou aux légumes) permettent aussi de varier les saveurs et les senteurs.

La préparation est on ne peut plus simple : quelques grammes de tisane à infuser dans de l’eau frémissante entre 5 et 10 minutes selon les recommandations et vous pourrez déguster votre boisson chaude pour absorber naturellement tous ses principes actifs. Pour en maximiser les effets, il est conseillé d’ajouter un peu de matière grasse comme un soupçon de beurre, du lait ou encore de l’huile végétale.

De plus, la consommation de tisane est facile à intégrer dans une routine quotidienne en prenant 1 à 3 tasses au cours de la journée, la dernière étant bien souvent associée au rituel du soir. Il suffit alors de s’installer confortablement pour boire votre boisson chaude, idéalement en limitant les écrans avant le coucher.

FuturaSciences

ASTRONOMY - Galaxies and a Comet

 2023 October 20

See Explanation.  Clicking on the picture will download the highest resolution version available.

Galaxies and a Comet
Image Credit & Copyright: Dan Bartlett

Explanation: Galaxies abound in this sharp telescopic image recorded on October 12 in dark skies over June Lake, California. The celestial scene spans nearly 2 degrees within the boundaries of the well-trained northern constellation Canes Venatici. Prominent at the upper left 23.5 million light-years distant is big, beautiful spiral galaxy NGC 4258, known to some as Messier 106. Eye-catching edge-on spiral NGC 4217 is above and right of center about 60 million light-years away. Just passing through the pretty field of view is comet C/2023 H2 Lemmon, discovered last April in image data from the Mount Lemmon Survey. Here the comet sports more of a lime green coma though, along with a faint, narrow ion tail stretching toward the top of the frame. This visitor to the inner Solar System is presently less than 7 light-minutes away and still difficult to spot with binoculars, but it's growing brighter. Comet C/2023 H2 Lemmon will reach perihelion, its closest point to the Sun, on October 29 and perigee, its closest to our fair planet, on November 10 as it transitions from morning to evening northern skies.

LES PLUS BEAUX ASTRES DE LA VOIE LACTéE - Pluton : la planète naine

Cette vue d'artiste représente la surface de Pluton , imaginée d'après les études scientifiques. Elle montre des amas de méthane sur...