ACTUALITE Aéronautique

ACTUALITE Aéronautique : Suivi et commentaire de l\'actualité aéronautique

L'espace par l'image


Whisky Quebec

Re: L'espace par l'image

Message par Jeannot le Sam 27 Déc 2014 - 10:25

Une belle photo de la Galaxie IC 135

Cette photo prise par Hubble montre la galaxie IC 335 en face de galaxies lointaines . IC 335 fait partie d'un groupe de galaxies contenant trois autres galaxies , et situé à 60 millions d'années-lumière

Hubble Sees the Beautiful Side of Galaxy IC 335
This new NASA/ESA Hubble Space Telescope image shows the galaxy IC 335 in front of a backdrop of distant galaxies. IC 335 is part of a galaxy group containing three other galaxies, and located in the Fornax Galaxy Cluster 60 million light-years away.
As seen in this image, the disk of IC 335 appears edge-on from the vantage point of Earth. This makes it harder for astronomers to classify it, as most of the characteristics of a galaxy’s morphology — the arms of a spiral or the bar across the center — are only visible on its face. Still, the 45 000 light-year-long galaxy could be classified as an S0 type.
These lenticular galaxies are an intermediate state in galaxy morphological classification schemes between true spiral and elliptical galaxies. They have a thin stellar disk and a bulge, like spiral galaxies, but in contrast to typical spiral galaxies they have used up most of the interstellar medium. Only a few new stars can be created out of the material that is left and the star formation rate is very low. Hence, the population of stars in S0 galaxies consists mainly of aging stars, very similar to the star population in elliptical galaxies.
As S0 galaxies have only ill-defined spiral arms they are easily mistaken for elliptical galaxies if they are seen inclined face-on or edge-on as IC 335 here. And indeed, despite the morphological differences between S0 and elliptical class galaxies, they share some common characteristics, like typical sizes and spectral features.
Both classes are also deemed "early-type" galaxies, because they are evolving passively. However, while elliptical galaxies may be passively evolving when we observe them, they have usually had violent interactions with other galaxies in their past.  In contrast,  S0 galaxies are either aging and fading spiral galaxies, which never had any interactions with other galaxies, or they are the aging result of a single merger between two spiral galaxies in the past. The exact nature of these galaxies is still a matter of debate.

Whisky Quebec

Re: L'espace par l'image

Message par Jeannot le Sam 27 Déc 2014 - 10:41

Ravins givrés sur Mars

Cette photo du 30/11/2014 montre des ravins givrés sur la face sud d'un cratère de Mars.

Frosty Slopes on Mars
This image of an area on the surface of Mars, approximately 1.5 by 3 kilometers in size, shows frosted gullies on a south-facing slope within a crater.
At this time of year, only south-facing slopes retain the frost, while the north-facing slopes have melted. Gullies are not the only active geologic process going on here. A small crater is visible at the bottom of the slope.
The image was acquired on Nov. 30, 2014, by the High Resolution Imaging Science Experiment (HiRISE) camera, one of six instruments on NASA's Mars Reconnaissance Orbiter. The University of Arizona, Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp., Boulder, Colorado. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter Project for NASA's Science Mission Directorate, Washington.

Whisky Quebec

Re: L'espace par l'image

Message par Jeannot le Lun 29 Déc 2014 - 7:40

Belle éruption solaire du 19 décembre 2014

Où on apprend la classification des éruptions solaires avec les appelations X1.8 etc...

Holiday Lights on the Sun: Imagery of a Solar Flare
The sun emitted a significant solar flare, peaking at 7:28 p.m. EST on Dec. 19, 2014. NASA’s Solar Dynamics Observatory, which watches the sun constantly, captured an image of the event. Solar flares are powerful bursts of radiation. Harmful radiation from a flare cannot pass through Earth's atmosphere to physically affect humans on the ground, however -- when intense enough -- they can disturb the atmosphere in the layer where GPS and communications signals travel. This flare is classified as an X1.8-class flare. X-class denotes the most intense flares, while the number provides more information about its strength. An X2 is twice as intense as an X1, an X3 is three times as intense, etc.

Whisky Quebec

Re: L'espace par l'image

Message par Jeannot le Ven 2 Jan 2015 - 8:35

Hubble analyse une usine à étoiles

Hubble Sweeps a Messy Star Factory
This sprinkle of cosmic glitter is a blue compact dwarf galaxy known as Markarian 209. Galaxies of this type are blue-hued, compact in size, gas-rich, and low in heavy elements. They are often used by astronomers to study star formation, as their conditions are similar to those thought to exist in the early Universe.
Markarian 209 in particular has been studied extensively. It is filled with diffuse gas and peppered with star-forming regions towards its core. This image captures it undergoing a particularly dramatic burst of star formation, visible as the lighter blue cloudy region towards the top right of the galaxy. This clump is filled with very young and hot newborn stars.
This galaxy was initially thought to be a young galaxy undergoing its very first episode of star formation, but later research showed that Markarian 209 is actually very old, with an almost continuous history of forming new stars. It is thought to have never had a dormant period — a period during which no stars were formed — lasting longer than 100 million years.
The dominant population of stars in Markarian 209 is still quite young, in stellar terms, with ages of under 3 million years. For comparison, the sun is some 4.6 billion years old, and is roughly halfway through its expected lifespan.
The observations used to make this image were taken using Hubble’s Wide Field Camera 3 and Advanced Camera for Surveys, and span the ultraviolet, visible, and infrared parts of the spectrum. A scattering of other bright galaxies can be seen across the frame, including the bright golden oval that could, due to a trick of perspective, be mistaken as part of Markarian 209 but is in fact a background galaxy.

Whisky Quebec

Re: L'espace par l'image

Message par Jeannot le Ven 2 Jan 2015 - 9:03

Curioisty mesure du Méthane sur Mars

NASA Rover Finds Active, Ancient Organic Chemistry on Mars
Curiosity a détecté des molécules de méthane et d'autres molécules organiques dans l'atmosphère qui l'entoure et dans la poussière de rochers issue d'un fotage qu'il a effectué.

NASA's Mars Curiosity rover has measured a tenfold spike in methane, an organic chemical, in the atmosphere around it and detected other organic molecules in a rock-powder sample collected by the robotic laboratory’s drill.
"This temporary increase in methane -- sharply up and then back down -- tells us there must be some relatively localized source," said Sushil Atreya of the University of Michigan, Ann Arbor, and Curiosity rover science team. "There are many possible sources, biological or non-biological, such as interaction of water and rock."
Researchers used Curiosity’s onboard Sample Analysis at Mars (SAM) laboratory a dozen times in a 20-month period to sniff methane in the atmosphere. During two of those months, in late 2013 and early 2014, four measurements averaged seven parts per billion. Before and after that, readings averaged only one-tenth that level.
Curiosity also detected different Martian organic chemicals in powder drilled from a rock dubbed Cumberland, the first definitive detection of organics in surface materials of Mars. These Martian organics could either have formed on Mars or been delivered to Mars by meteorites.
Organic molecules, which contain carbon and usually hydrogen, are chemical building blocks of life, although they can exist without the presence of life. Curiosity's findings from analyzing samples of atmosphere and rock powder do not reveal whether Mars has ever harbored living microbes, but the findings do shed light on a chemically active modern Mars and on favorable conditions for life on ancient Mars.
"We will keep working on the puzzles these findings present," said John Grotzinger, Curiosity project scientist of the California Institute of Technology in Pasadena (Caltech). "Can we learn more about the active chemistry causing such fluctuations in the amount of methane in the atmosphere? Can we choose rock targets where identifiable organics have been preserved?"
Researchers worked many months to determine whether any of the organic material detected in the Cumberland sample was truly Martian. Curiosity’s SAM lab detected in several samples some organic carbon compounds that were, in fact, transported from Earth inside the rover. However, extensive testing and analysis yielded confidence in the detection of Martian organics.
Identifying which specific Martian organics are in the rock is complicated by the presence of perchlorate minerals in Martian rocks and soils. When heated inside SAM, the perchlorates alter the structures of the organic compounds, so the identities of the Martian organics in the rock remain uncertain.
"This first confirmation of organic carbon in a rock on Mars holds much promise," said Curiosity participating scientist Roger Summons of the Massachusetts Institute of Technology in Cambridge. "Organics are important because they can tell us about the chemical pathways by which they were formed and preserved. In turn, this is informative about Earth-Mars differences and whether or not particular environments represented by Gale Crater sedimentary rocks were more or less favorable for accumulation of organic materials. The challenge now is to find other rocks on Mount Sharp that might have different and more extensive inventories of organic compounds."
Researchers also reported that Curiosity's taste of Martian water, bound into lakebed minerals in the Cumberland rock more than three billion years ago, indicates the planet lost much of its water before that lakebed formed and continued to lose large amounts after.
SAM analyzed hydrogen isotopes from water molecules that had been locked inside a rock sample for billions of years and were freed when SAM heated it, yielding information about the history of Martian water. The ratio of a heavier hydrogen isotope, deuterium, to the most common hydrogen isotope can provide a signature for comparison across different stages of a planet's history.
"It's really interesting that our measurements from Curiosity of gases extracted from ancient rocks can tell us about loss of water from Mars," said Paul Mahaffy, SAM principal investigator of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and lead author of a report published online this week by the journal Science
The ratio of deuterium to hydrogen has changed because the lighter hydrogen escapes from the upper atmosphere of Mars much more readily than heavier deuterium. In order to go back in time and see how the deuterium-to-hydrogen ratio in Martian water changed over time, researchers can look at the ratio in water in the current atmosphere and water trapped in rocks at different times in the planet’s history.
Martian meteorites found on Earth also provide some information, but this record has gaps. No known Martian meteorites are even close to the same age as the rock studied on Mars, which formed about 3.9 billion to 4.6 billion years ago, according to Curiosity’s measurements.
The ratio that Curiosity found in the Cumberland sample is about one-half the ratio in water vapor in today's Martian atmosphere, suggesting much of the planet's water loss occurred since that rock formed. However, the measured ratio is about three times higher than the ratio in the original water supply of Mars, based on assumption that supply had a ratio similar to that measured in Earth's oceans. This suggests much of Mars' original water was lost before the rock formed.
Curiosity is one element of NASA's ongoing Mars research and preparation for a human mission to Mars in the 2030s. Caltech manages the Jet Propulsion Laboratory in Pasadena, California, and JPL manages Curiosity rover science investigations for NASA's Science Mission Directorate in Washington. The SAM investigation is led by Paul Mahaffy of Goddard. Two of SAM instruments key in these discoveries are the Quadrupole Mass Spectrometer, developed at Goddard, and the Tunable Laser Spectrometer, developed at JPL.
The results of the Curiosity rover investigation into methane detection and the Martian organics in an ancient rock were discussed at a news briefing Tuesday at the American Geophysical Union's convention in San Francisco. The methane results are described in a paper published online this week in the journal Science by NASA scientist Chris Webster of JPL, and co-authors.
A report on organics detection in the Cumberland rock by NASA scientist Caroline Freissinet, of Goddard, and co-authors, is pending publication.

Whisky Quebec

Re: L'espace par l'image

Message par Jeannot le Mer 14 Jan 2015 - 11:31

Décollage de la navette le 12/01.1986. La photo est ,'est pas récente mais tellement belle !

Whisky Quebec

Re: L'espace par l'image

Message par Jeannot le Sam 7 Fév 2015 - 15:36

Curiosity photographié par la camera HIRISE de Mars Orbiter

Photographie prise le 13 décembre 2014. Le Rover est dans un cadre au centre de l'image avec son ombre dirigée vers le coin supérieur droit. Extraordinaire tout de même de pouvoir obtenir ce type de photographie. Non ?

Curiosity Rover at 'Pahrump Hills'
NASA's Curiosity Mars rover can be seen at the "Pahrump Hills" area of Gale Crater in this view from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter.  Pahrump Hills is an outcrop at the base of Mount Sharp. The region contains sedimentary rocks that scientists believe formed in the presence of water.
The location of the rover, with its shadow extending toward the upper right, is indicated with an inscribed rectangle. Figure A is an unannotated version of the image.  North is toward the top. The view covers an area about 360 yards (330 meters) across. 
HiRISE made the observation on Dec. 13, 2014. At that time, Curiosity was near a feature called "Whale Rock."  A map showing the rover's path for the weeks leading up to that date is at .  The inset map at labels the location of Whale Rock and other features in the Pahrump Hills area.
The bright features in the landscape are sedimentary rock and the dark areas are sand.  The HiRISE team plans to periodically image Curiosity, as well as NASA's other active Mars rover, Opportunity, as the vehicles continue to explore Mars.
This image is an excerpt from HiRISE observation ESP_039280_1755. Other image products from this observation are available at .
The University of Arizona, Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp., Boulder, Colorado. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter Project and Mars Science Laboratory Project for NASA's Science Mission Directorate, Washington. 
Image Credit: NASA/JPL-Caltech/Univ. of Arizona

Whisky Quebec

Re: L'espace par l'image

Message par Jeannot le Ven 13 Fév 2015 - 12:37

Whisky Quebec

Re: L'espace par l'image

Message par eolien le Ven 13 Fév 2015 - 15:10

Je ne vois pas son iPad ...

La dialectique est l'art d'atteindre la vérité au moyen de la discussion des opinions.

Laurent Simon
Whisky Quebec

Re: L'espace par l'image

Message par Laurent Simon le Ven 6 Mar 2015 - 11:55

Au sujet du survol récent de la comète par la sonde Rosetta,
et quelques photos en très haute résolution prise à cette occasion

Un vol au-dessus de Tchouri, ça vous botte ?

Voir aussi le fil spécifique :


Re: L'espace par l'image

Message par Zebulon84 le Sam 7 Mar 2015 - 3:10

Vu Cérès, "planète naine" au cœur de la ceinture d’astéroïde entre Mars et Jupiter, vu par la sonde Dawn le 19 février dernier :

Les points lumineux intriguent toujours les astronomes qui n'ont pas d'explication définitive. Mais le reste de la planète étant très sombre, c'est probablement simplement un lieux avec une matière bien plus réfléchissante comme de la glace .

Whisky Quebec

Re: L'espace par l'image

Message par Jeannot le Dim 8 Mar 2015 - 13:22

Dans la continuité des messages précédents.

La sonde Dawn se met en orbite autour de la planète naine Ceres

Ceres Seen From NASA's Dawn Spacecraft
NASA's Dawn spacecraft has become the first mission to achieve orbit around a dwarf planet. The spacecraft was approximately 38,000 miles (61,000) kilometers from Ceres when it was captured by the dwarf planet’s gravity at about 4:39 a.m. PST (7:39 a.m. EST) Friday, March 6.
This image of Ceres was taken by the Dawn spacecraft on March 1, just a few days before the mission achieved orbit around the previously unexplored world. The image shows Ceres as a crescent, mostly in shadow because the spacecraft's trajectory put it on a side of Ceres that faces away from the sun until mid-April. When Dawn emerges from Ceres' dark side, it will deliver ever-sharper images as it spirals to lower orbits around the planet.
The image was obtained at a distance of about 30,000 miles (about 48,000 kilometers) at a sun-Ceres-spacecraft angle, or phase angle, of 123 degrees. Image scale on Ceres is 1.9 miles (2.9 kilometers) per pixel. Ceres has an average diameter of about 590 miles (950 kilometers).
Dawn's mission is managed by NASA's Jet Propulsion Laboratory, Pasadena, California, for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. The University of California, Los Angeles, is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute are international partners on the mission team. For a complete list of acknowledgments,

Laurent Simon
Whisky Quebec

Re: L'espace par l'image

Message par Laurent Simon le Ven 20 Mar 2015 - 19:22

Comment Rosetta prend de sublimes clichés avec de vieux appareils photo

extraits :

Des falaises escarpées et des jets de gaz colossaux sur fond de vide spatial : difficile de ne pas être sidéré par les paysages de la comète "Tchouri" qu'immortalise Rosetta, la sonde de l'Agence spatiale européenne (ESA).
Depuis le placement du vaisseau en orbite autour de l'objet stellaire, puis l'atterrissage plein d'émotions du robot Philae, les images parviennent à la Terre à un rythme de métronome, nourrissant les études scientifiques et étanchant la soif d'images du public. 

Quatre appareils photo répartis entre l'orbiteur Rosetta et l'atterrisseur Philae participent à découvrir les secrets de la comète 67P/Tchourioumov-Guérassimenko.

L'appareil-star de la mission s'appelle Osiris. Pourquoi ce nom ? D'abord parce que l'ESA, s'étant inspirée de la pierre de Rosette pour nommer sa mission, se plaît depuis à puiser dans l'onomastique égyptienne. Ensuite parce qu'Osiris est l'acronyme – attention, jargon – de Optical, Spectroscopic, and Infrared Remote Imaging System, c'est-à-dire système d’imagerie optique, spectroscopique et infrarouge à distance.

Intégré à la sonde, ce gros bébé de 30 kilos recèle en fait deux appareils photo : le premier, muni d'un grand angle, est destiné à cadrer la comète en son entier et le gaz qui en émane. Le second, pourvu d'une longue focale, réalise des plans rapprochés du noyau.

Chacun dispose d'une batterie de filtres permettant d'atténuer la lumière du soleil ou d'analyser des aspects spécifiques de Tchouri. Bref, l'appareil Osiris est à l'image de son dieu tutélaire : il voit tout. Enfin, tout ce qui se trouve entre le proche infrarouge et l'ultraviolet.

Laurent Simon
Whisky Quebec

Rosetta, les récentes photos prises lors du survol de la comète, très bas

Message par Laurent Simon le Lun 6 Avr 2015 - 13:23

L’ESA publie d’incroyables images prises par Rosetta

Exemple :

Dernière édition par Laurent Simon le Lun 6 Avr 2015 - 14:49, édité 1 fois

Laurent Simon
Whisky Quebec

De superbes photos, prises par Sentinel1A, au cours de sa première année en orbite

Message par Laurent Simon le Lun 6 Avr 2015 - 14:44

Des photos superbes, prise par le premier satellite (Sentinel 1A) de Copernicus, au cours de la première année en orbite :

European Space Agency satellite captures stunning images of cityscapes, earthquakes and meandering glaciers

Exemple, parmi les autres publiés à ce lien
The European Space Agency’s Sentinel mission has completed its inaugural year.

Launched on April 3, 2014, Sentinel-1a — the vanguard of a fleet of satellites being launched by the ESA — carries a so-called synthetic aperture radar that provides continuous imagery of the earth’s surface no matter what the weather.

The project, which is part of the ESA’s Copernicus program, was created for land and sea monitoring, mapping of natural disasters, and sea ice observation. Here, Bloomberg looks at some of the amazing imagery those first 12 months have produced, including incredible cityscapes, meandering glaciers, and the terrain following a magnitude 6.0 earthquake striking California’s Napa Valley in August, 2014.

Laurent Simon
Whisky Quebec

Re: L'espace par l'image

Message par Laurent Simon le Lun 6 Avr 2015 - 14:53

Laurent Simon a écrit:Comment Rosetta prend de sublimes clichés avec de vieux appareils photo

J'aurais dû copier l'image :

Laurent Simon
Whisky Quebec

Une des permières photos prises par Sentinel1A, sur le tremblement de terre Napa Valley

Message par Laurent Simon le Lun 6 Avr 2015 - 15:21

Laurent Simon
Whisky Quebec

Rosetta : Des photos des jets de poussière par la comète.

Message par Laurent Simon le Jeu 23 Avr 2015 - 14:39

Des photos des jets de poussière partant de la comète

Rosetta probe sees comet sprout new dust jet for first time

Laurent Simon
Whisky Quebec

Comment 3 scans radar de Sentinel 1A peuvent être utilisés pour visualiser les cultures

Message par Laurent Simon le Mar 5 Mai 2015 - 18:46

Une image qui combine 3 clichés radar (à différentes dates)

depuis le satellite Sentinel 1A
(programme européen Copernicus, de grande ampleur, le 2e juste après Galileo ; budget d'env. 4 milliards d'euros, pour la période 2014-2020, comportant une prévision de 3 786 M€  cf Wikipedia )

Central and Southern Italy

This image combines three radar scans from the Sentinel-1A satellite in October and December 2014.

Focusing on the right side of the image, we can see how different colors represent changes between the acquisitions in the agricultural structures, due to plant growth or harvest.

Dernière édition par Laurent Simon le Mar 5 Mai 2015 - 19:16, édité 1 fois

Laurent Simon
Whisky Quebec

Sentinel 1A, observe le Népal (séisme)

Message par Laurent Simon le Mar 5 Mai 2015 - 18:57

Laurent Simon
Whisky Quebec

Pluton, des images inédites. New Horizons.

Message par Laurent Simon le Ven 18 Sep 2015 - 18:02

Pluton : des images spectaculaires et inédites de ses reliefs

Cette image de Pluton a été prise par la sonde New Horizons le 14 juillet 2015, à quelque 18.000 km de distance, 15 mn après le survol de la région Tombaugh et de la plaine Spoutnik.

On aperçoit une partie de cette dernière, sur le limbe, à droite. Les montagnes qui la bordent, en bas et à sa gauche (est) sont Norgay Montes.

Plus haut, sur l’horizon, on distingue Hillary Montes.

Par-dessus, on compte, dans son atmosphère riche en azote, plus d’une douzaine de couches de brume jusqu’à 100 km d’altitude.

L’image couvre une portion de 1.250 km. Téléchargez l’image en haute résolution ici (3,7 Mo). © Nasa, JHUAPL, SwRI


Vue détaillée de la plaine Spoutnik (partie droite) et de ses glaciers coulants. À gauche et en bas, Norgay Montes.

Certaines de ces montagnes culminent à 3.500 m.

À l’horizon, les reliefs de Hillary Montes.

Les brumes sont rétroéclairées par le Soleil couchant.

L’image couvre une région qui s’étend sur 380 km. Téléchargez l’image en haute résolution ici (2,2 Mo). © Nasa, JHUAPL, SwRI

Whisky Quebec

Re: L'espace par l'image

Message par Jeannot le Mer 24 Fév 2016 - 9:12

Trois lunes de Saturne

Trois lunes de Saturnen Téthys, Enceladus et Mimas prises par la sonde Cassini le 3 décembre 2015

Three of Saturn's moons -- Tethys, Enceladus and Mimas -- are captured in this group photo from NASA's Cassini spacecraft.

Tethys (660 miles or 1,062 kilometers across) appears above the rings, while Enceladus (313 miles or 504 kilometers across) sits just below center. Mimas (246 miles or 396 kilometers across) hangs below and to the left of Enceladus.

This view looks toward the sunlit side of the rings from about 0.4 degrees above the ring plane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Dec. 3, 2015.

The view was acquired at a distance of approximately 837,000 miles (1.35 million kilometers) from Enceladus, with an image scale of 5 miles (8 kilometers) per pixel. Tethys was approximately 1.2 million miles (1.9 million kilometers) away with an image scale of 7 miles (11 kilometers) per pixel.  Mimas was approximately 1.1 million miles (1.7 million kilometers) away with an image scale of 6 miles (10 kilometers) per pixel.

The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.

For more information about the Cassini-Huygens mission visit and . The Cassini imaging team homepage is at .

Whisky Quebec

Re: L'espace par l'image

Message par Jeannot le Ven 22 Avr 2016 - 10:53

Curieuse photo d'Enceladus

Prise par la sonde Cassini le 15 fevrier 2016, cette photo d'Enceladus, satellite de Saturne. Un pixel correspond à 580 mètres.

A sinuous feature snakes northward from Enceladus' south pole like a giant tentacle. This feature, which stretches from the terminator near center, toward upper left, is actually tectonic in nature, created by stresses in Enceladus' icy shell.

Geologists call features like these on Enceladus (313 miles or 504 kilometers across) "Y-shaped discontinuities." These are thought to arise when surface material attempts to push northward, compressing or displacing existing ice along the way. Such features are also believed to be relatively young based on their lack of impact craters -- a reminder of how surprisingly geologically active Enceladus is.

This view looks towards the trailing hemisphere of Enceladus. North is up. The image was taken in visible green light with the Cassini spacecraft narrow-angle camera on Feb. 15, 2016.

The view was obtained at a distance of approximately 60,000 miles (100,000 kilometers) from Enceladus. Image scale is 1,900 feet (580 meters) per pixel.

Whisky Quebec

Re: L'espace par l'image

Message par Jeannot le Mer 27 Avr 2016 - 13:25

Des échos de lumière utilisés pour étudier les disques protoplanétaires. 

La Nasa a utilisé le télescope Spitzer et 4 télescopes terrestres pour mesure la distance entre une etoile et son disque protoplanétaire.

Personnellement j'ai appris ce qu'était un disque protoplanétaire et pus la photo est belle. Non ?

A new study published in the Astrophysical Journal uses data from NASA's Spitzer Space Telescope and four ground-based telescopes to determine the distance from a star to the inner rim of its surrounding protoplanetary disk. Researchers used a method called "photo-reverberation," also known as "light echoes." When the central star brightens, some of the light hits the surrounding disk, causing a delayed “echo.” Scientists measured the time it took for light coming directly from the star to reach Earth, then waited for its echo to arrive.
The Spitzer study marks the first time the light echo method was used in the context of protoplanetary disks.
This illustration shows a star surrounded by a protoplanetary disk. Material from the thick disk flows along the star’s magnetic field lines and is deposited onto the star’s surface. When material hits the star, it lights up brightly.

Whisky Quebec

Re: L'espace par l'image

Message par Jeannot le Jeu 5 Mai 2016 - 17:33

Les couleurs de Nili Fossae sur Mars

Quel jeu de couleurs pour une région de la planète rouge. On pourrait presque croire voir une photo de lnotre bonne vieille terre.

The Nili Fossae region, located on the northwest rim of Isidis impact basin, is one of the most colorful regions of Mars. The colors over many regions of Mars are homogenized by the dust and regolith, but here the bedrock is very well exposed, except where there are sand dunes. The rocks also have diverse compositions. This region is ancient and has had a complicated geologic history, leading to interesting structures like layered bedrock, as well as other compositions.
This image of Nili Fossae was taken on Feb. 5, 2016, at 14:54 local Mars time by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. The University of Arizona, Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp., Boulder, Colo. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter Project for NASA's Science Mission Directorate, Washington.
Image Credit: NASA/JPL-Caltech/Univ. of Arizona
Caption: Alfred McEwen

Laurent Simon
Whisky Quebec

Re: L'espace par l'image

Message par Laurent Simon le Sam 1 Oct 2016 - 12:43

J'avais oublié ce fil, image et vidéo,
et je doublonne donc ici le dernier message, sur le fil Rosetta :

La video sur l'article déjà cité :

est vraiment excellente, mais je n'ai pas réussi à l'intégrer ici.
Elle inclut des précisions non trouvées sur les articles que j'ai pu lire, y compris, par exemple, pourquoi il était plus difficile de faire "atterrir"
 la sonde Rosetta, et pourquoi il n'était pas sûr de garder le contact jusqu'à la fin.

C'est en fait une vidéo Euronews, de 8mn,
(qui est peut-être accessible et 'copiable' sur le site euronews)

qui d'ailleurs inclut également env. 30 secondes à la fin pour évoquer Exomars, qui s'approche actuellement de Mars.

et j'y ajoute cet article du Huffington Post :
Les dernières photos prises par Rosetta avant de s'écraser sur Tchouri

qui inclut effectivement de superbes photos, dans la descente,
que je n'ai pas réussi non plus à intégrer ici.

Laurent Simon
Whisky Quebec

Re: L'espace par l'image

Message par Laurent Simon le Lun 17 Oct 2016 - 1:57

Des vidéos, sur ExoMars 2016,
sur le site de l'ESA, 
ou  :

ExoMars separation confirmation

At the end of this live webcast, at about 17:30 CEST on 16 October, the data link with the ExoMars/TGO orbiter had still not been fully re-established following separation. Subsequently, at around 18:40 CEST, ESA re-established a full data link with the spacecraft, and the mission control team could confirm that separation had taken place as planned, at 16:42 CEST. Both the Schiaparelli module and the TGO orbiter are in good shape and en route - seperately - to arrive at the Red Planet on 19 October.

et :

13 October 2016
Updates from ESA’s space operations centre as the ExoMars Trace Gas Orbiter approaches and enters orbit around the Red Planet, and the Schiaparelli module lands on its surface
Updates on this page will cover the following expected milestones:
14 October: TGO final trajectory manoeuvre (08:45 GMT)
16 October: Separation of Schiaparelli from TGO at 14:42 GMT / 16:42 CEST
17 October: TGO orbit-raising manoeuvre at 02:42 GMT / 04:42 CEST
19 October: TGO Mars orbit insertion and Schiaparelli entry, descent and landing on Mars (atmospheric entry expected 14:42 GMT / 16:42 CEST, landing 14:48 GMT / 16:48 CEST)
20 October: Update on Schiaparelli status; descent images expected
21+ October: Schiaparelli status reports until end of mission
Note: Times shown above are actual event times at Mars; the one-way signal travel time between Earth and Mars is currently just under 10 minutes.
The events of 16, 19 and 20 October will also be livestreamed here, all other events will be reported on this page and via Twitter from @esaoperations, @ESA_ExoMars, @ESA_TGO and @ESA_EDM, and via the hashtag #ExoMars.

Mise à jour, au 16 octobre :
16 October
18:43 CEST: Full telemetry link with ExoMars/TGO has been restored via ESA's 35m deep-space ground station at Malargüe, Argentina. 
18:30 CEST: The Schiaparelli module was released from the Trace Gas Orbiter (TGO) at 14:42 GMT (16:42 CEST) as planned.
Today, three days before gravity will ensure the arrival of ExoMars 2016 at Mars, the Schiaparelli Entry, Descent & landing demonstrator Module separated from the TGO orbiter and is now en route on a ballistic trajectory to reach the Red Planet, enter its atmosphere and land softly in an area close to the equator known as Meridiani Planum.
However, TGO unexpectedly did not return telemetry (on-board status information), and sent only its carrier signal, indicating it is operational. The anomaly that prevents TGO's telemetry from being sent is under investigation, and is expected to be resolved within the next few hours.
An update will be posted in the next few hours.
17:27 CEST: ExoMars Flight Director Michel Denis confirmed that separation of Schiaparelli has occurred and and signals from TGO have been reacquired. The signals do not contain the expected telemetry (information on the onboard status), and the teams are investigating the situation.
17:02 CEST: Flight dynamics team at ESOC confirms separation of Schiaparelli from TGO on the basis of Doppler signal from the carrier. The Giant Metrewave Radio Telescope (GMRT) near Pune, India, has also recorded a very faint signal that indicates separation. Official confirmation expected soon when telemetry from TGO is received.
16:42 CEST: According to the timeline, Schiaparelli should have separated from TGO. Confirmation is expected on Earth soon and will be announced by ExoMars Flight Director Michel Denis once the data is on ground.
15:50 CEST: Both Schiaparelli and ExoMars/TGO are in good shape! The A-team shift of the mission control team are now on console in Main Control Room at ESOC. ExoMars/TGO has completed its slew into separation attitude/orientation. Communication now provided by ESA's 35m deep-space tracking station at New Norcia, Australia. Separation on track for 16:42 CEST.
13:25 CEST: The separation timeline has started! Teams at ESOC are extremely busy monitoring the sequence of events scheduled for today's separation, expected at 16:42 CEST. Both the ExoMars/TGO orbiter and the Schiaparelli lander module are in great shape. The lander has been switched on and engineers monitoring telemetry - on-board status information - report that temperatures on Schiaparelli are nominal. ExoMars/TGO has already begun slewing - rotating in space - into the correct attitude for separation. Just prior to separation, at 16:31 CEST, mission controllers expect to lose the full data link with TGO, and then will follow progress by monitoring the basic unmodulated carrier signal only, as a sort of beacon. We may also see signals received via the GMRT radio telescope in Pune, India, although this is strictly an experiment and may not function as planned. One-way signal time today is 9 mins and 34 secs.
10:10 CEST: Today, Schiaparelli, still attached to ExoMars/TGO, is switched on, and its systems checked out one final time. Experts from Thales Alenia Space (Italy) working at ESOC will verify the final set of time-tagged commands, which have been uploaded via TGO and stored on board Schiaparelli so that it can function more or less autonomously throughout its mission. TGO will eject Schiaparelli at 16:42 CEST, dispatching it on a three-day coast and a six-minute descent to the surface. Ground station coverage will be provided by NASA's giant 70m Deep Space Network (DSN) ground stations at Canberra, Australia, and Madrid, Spain, which will listen for the spacecraft's signals as the Schiaparelli module separates. It will be pushed away from TGO at just 30 cm/second, but this tiny push can be detected by the DSN stations.

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Re: L'espace par l'image

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    La date/heure actuelle est Mar 21 Fév 2017 - 15:15