Astronautas em perigo aterraram de emergência - Video - Espaço

O astronauta Nick Hague da NASA e o cosmonauta Alexey Ovchinin da Roscosmos regressaram à Terra depois de o foguetão russo Soyuz que os levaria até à Estação Espacial Internacional ter acusado erros de funcionamento minutos depois da descolagem em direção ao espaço. A agência espacial norte-americana diz que os astronautas detetaram problemas no motor da aeronave, que fez um regresso de emergência à Terra em modo balístico. Os astronautas voltaram em segurança e já saíram da cápsula russa.

No momento em que o erro foi detetado é possível ouvir um sinal de alerta e a mensagem: “Inaudível. Há uma emergência. Há uma falha no impulsionador. Estamos em ausência de peso”. Às 10h20, os astronautas aterraram em segurança no Cazaquistão e estão agora a ser acudidos pelas equipas de busca e salvamento. A agência espacial norte-americana diz que os dois astronautas estão “em boas condições”.

Observador - Portugal

Sun Dance - Astronomy picture of the day - 2018 October 10

Sun Dance 
Video Credit: NASA, SDO; Processing: Alan Watson via Helioviewer Explanation: Sometimes, the surface of our Sun seems to dance. In the middle of 2012, for example, NASA's Sun-orbiting Solar Dynamic Observatory spacecraft imaged an impressive prominence that seemed to perform a running dive roll like an acrobatic dancer. The dramatic explosion was captured in ultraviolet light in the featured time-lapse video covering about three hours. A looping magnetic field directed the flow of hot plasma on the Sun. The scale of thedancing prominence is huge -- the entire Earth would easily fit under the flowing arch of hot gas. A quiescent prominence typically lasts about a month, and may erupt in a Coronal Mass Ejection (CME) expelling hot gas into the Solar System. The energy mechanism that creates a solar prominence is still a topic of research. Unlike 2012, this year the Sun's surface is significantly more serene, featuring fewer spinning prominences, as it is near the minimum in its 11-year magnetic cycle.

Era - "Ameno" - Video - Musica

"Ameno"

The Last Days of Venus as the Evening Star - Astronomy picture of the day - 2018 October 5

The Last Days of Venus as the Evening Star Image Credit & Copyright: Radu-Mihai Anghel

Explanation: That's not a young crescent Moon poised above the hills along the western horizon at sunset. It's Venus in a crescent phase. About 54 million kilometers away and less than 20 percent illuminated, it was captured by telescope and camera on September 30 near Bacau, Romania. The bright celestial beacon is now languishing in the evening twilight, its days as the Evening Star in 2018 coming to a close. But it also grows larger in apparent size and becomes an ever thinner crescent in telescopic views. Heading toward an inferior conjunction (non-judgmental), the inner planet will be positioned between Earth and Sun on October 26 and lost from view in the solar glare. At month's end a crescent Venus will reappear in the east though, rising just before the Sun as the brilliant Morning Star.

Opportunity After the Storm - Astronomy picture of the day - 2018 October 4

Opportunity After the Storm  Image Credit: HiRISE, MRO, LPL (U. Arizona), NASA

Explanation: On Mars dust storms can't actually blow spacecraft over, but they can blot out the Sun. Over three months ago a planet-wide dust storm caused a severe lack of sunlight for the Mars rover Opportunity at its location near the west rim of Endeavour crater. The lack of sunlight sent the solar-powered Opportunity into hibernation and for over 115 sols controllers have not received any communication from the rover. The dust is clearing as the storm subsides though. On September 20th, when this image was taken by the Mars Reconnaissance Orbiter's HiRISE camera, about 25 percent of the sunlight was reaching the surface again. The white box marks a 47-meter-wide (154-foot-wide) area centered on a blip identified as the silent-for-now Opportunity rover.

NGC 1898: Globular Cluster in the Large Magellanic Cloud - Astronomy picture of the day - 2018 October 3

NGC 1898: Globular Cluster in the Large Magellanic Cloud Image Credit: ESA/Hubble & NASA

Explanation: Jewels don't shine this bright -- only stars do. And almost every spot in this glittering jewel-box of an image from the Hubble Space Telescope is a star. Now some stars are more red than our Sun, and some more blue -- but all of them are much farther away. Although it takes light about 8 minutes to reach Earth from the Sun, NGC 1898 is so far away that it takes light about 160,000 years to get here. This huge ball of stars, NGC 1898, is called aglobular cluster and resides in the central bar of the Large Magellanic Cloud (LMC) -- a satellite galaxy of our large Milky Way Galaxy. The featured multi-colored image includes light from the infrared to the ultraviolet and was taken to help determine if the stars of NGC 1898 all formed at the same time, or at different times. There are increasing indications that most globular clusters formed stars in stages, and that, in particular, stars from NGC 1898 formed shortly after ancient encounters with the Small Magellanic Cloud (SMC) and our Milky Way Galaxy.

Sciences et Avenir - Vaccin cubain contre le cancer - Santé/Médecine

"Si vous cherchez un vaccin contre le cancer du poumon, allez à Cuba, il existe", affirmait Jean-Luc Mélenchon jeudi 27 septembre 2018 devant l'Assemblée nationale, dans un discours ayant pour objectif de mettre l'Amérique du sud en valeur. Le produit dont il est question, le CIMAvax-EGF, est en effet une immunothérapie qui, comme un vaccin, s'appuie sur les défenses immunitaires du patient pour agir sur la durée. Cependant, il n'a pas encore montré, comme les vaccins usuels, la capacité de prévenir la maladie.

Découvert dans les années 90 par le Centre d’immunologie moléculaire de La Havane (Cuba), le CIMAvax-EGF fonctionne par des injections toutes les deux semaines puis chaque mois. Il permet au corps de produire des anticorps dirigés contre une certaine protéine, l'EGF ("Endothelial Growth Factor", ou en français "facteur de croissance endothélial"). Pour rendre le corps intolérant à l'EGF qu'il contient naturellement, le CIMAvax-EGF associe à l'EGF une protéine bactérienne qui stimule les défenses immunitaires et les force à cibler l'EGF.

Lire + sur : 
https://www.sciencesetavenir.fr/sante/cancer/

Sciences et Avenir - Le Portugal se dote d'une base spatiale - Espace

Le Newspace gagne le Portugal. Après l'annonce du Royaume-Uni, en juillet, de l'installation d'une base spatiale dans la région de Sutherland, en Écosse, c'est au tour de Lisbonne d'annoncer sa volonté de créer un “port spatial” sur l'île de Santa Maria, dans l'archipel des Açores. Outre que le site choisi dispose déjà d'installations de suivi des satellites, il possède par ailleurs de grands avantages géographiques : isolé au milieu de l'Atlantique, l'archipel permet de viser tous azimuts sans crainte de retombée sur des zones habitées. Son principal défaut, cependant, est de subir une météo capricieuse, qui pourrait mener à de fréquents reports de lancement. Pour le ministre de la Science et de la Technologie Manuel Heitor, qui s'exprimait ce 2 octobre à Brême (Allemagne) à l'occasion de l'IAC (International Astronautical Congress), il s'agit de se positionner sur le marché très concurrentiel de l'accès à bas coût de l'espace pour les petits lanceurs. Certes, le secteur est encore balbutiant : peu de petits lanceurs sont déjà en service, mais une centaine d'entre eux sont en développement au niveau mondial.

La première phase de ce “programme de lancement international de satellites Atlantic” consiste en un appel à idées pour faire émerger les besoins concrets de lancement des acteurs du monde entier. “Tout le monde est invité à se joindre au projet”, a souligné le ministre portugais. Le gouvernement de Lisbonne envisage d’investir quelque 60 millions d'euros dans des infrastructures portuaires en mer et pour l’espace. L’objectif annoncé est d’inaugurer cette nouvelle base atlantique à l’horizon 2021. Israël, l’Espagne, la Chine — soit des pays qui sont très restreints en terme d’azimuts, la Chine faisant régulièrement retomber des morceaux de fusées sur des zones habitées — pourraient être intéressés par des pas de tirs entourés de mer. “Les Portugais ont une vision à 360°, indique Piero Messina, directeur des vols habités à l’ESA (Agence spatiale européenne). Ils visent le développement de constellations de petits satellites pour des études de surveillance des océans, de pollutions maritimes, etc. L’idée est de développer un centre de recherches maritimes au centre de l’Atlantique.” L’aventure ne fait que commencer, une agence spatiale portugaise étant en cours de constitution…

Sciences et Avenir

Supernumerary Rainbows over New Jersey - Astronomy picture of the day - 2018 October 2

Supernumerary Rainbows over New Jersey Credit & Copyright: John Entwistle

Explanation: Yes, but can your rainbow do this? After the remnants of Hurricane Florence passed over Jersey Shore, New Jersey, USA last month, the Sun came out in one direction but something quite unusual appeared in the opposite direction: a hall of rainbows. Over the course of a next half hour, to the delight of the photographer and his daughter, vibrant supernumerary rainbows faded in and out, with at least five captured in this featured single shot.Supernumerary rainbows only form when falling water droplets are all nearly the same size and typically less than a millimeter across. Then, sunlight will not only reflect from inside the raindrops, but interfere, a wave phenomenon similar to ripples on a pond when a stone is thrown in. In fact, supernumerary rainbows can only be explained with waves, and their noted existence in the early 1800s was considered early evidence of light's wave nature.

The First Rocket Launch from Cape Canaveral - Astronomy picture of the day - 2018 October 1

The First Rocket Launch from Cape Canaveral 
Credit: NASA

Explanation: A new chapter in space flight began in 1950 with the launch of the first rocket from Cape Canaveral, Florida: the Bumper V-2. Featured here, the Bumper V-2 was an ambitious two-stage rocket program that topped aV-2 missile base with a WAC Corporal rocket. The upper stage was able to reach then-record altitudes of almost 400 kilometers, about the height of the modern International Space Station. Launched under the direction of theGeneral Electric Company, the Bumper V-2 was used primarily for testing rocket systems and for research on the upper atmosphere. Bumper V-2 rockets carried small payloads that allowed them to measure attributes including air temperature and cosmic ray impacts. Seven years later, the Soviet Union launched Sputnik I and Sputnik II, the first satellites into Earth orbit. In response in 1958, 60 years ago today, the USA created NASA.