ESA Astronaut Thomas Pesquet of France: "The Ural Delta in the Caspian Sea looks like a tree leaf."
"L’embouchure du fleuve Oural, qui se déverse dans la mer Caspienne, ressemble étrangement aux nervures d’une feuille d’arbre , Kazakhstan"
The Caspian Sea is the largest enclosed inland body of water on Earth by area, variously classed as the world's largest lake or a full-fledged sea. It is in an endorheic basin (a basin without outflows) located between Europe and Asia. It is bounded by Kazakhstan to the northeast, Russia to the northwest, Azerbaijan to the west, Iran to the south, and Turkmenistan to the southeast.
(Source: Wikipedia)
Credit: ESA/NASA
Capture Date: April 27, 2017#NASA #ESA #ISS #Science #Earth #EarthArt #Planet #UralDelta #CaspianSea #Astronaut #ThomasPesquet #Proxima #Expedition51 #Technology #Photography #JSC #CNES #France #Europe #OverviewEffect #OrbitalPerspective #STEM
#Education
May 8, 2017: Saturn's hexagonal polar jet stream is the shining feature of almost every view of the north polar region of Saturn. The region, in shadow for the first part of the Cassini mission, now enjoys full sunlight, which enables Cassini scientists to directly image it in reflected light.
Although the sunlight falling on the north pole of Saturn is enough to allow us to image and study the region, it does not provide much warmth. In addition to being low in the sky (just like summer at Earth's poles), the sun is nearly ten times as distant from Saturn as from Earth. This results in the sunlight being only about 1 percent as intense as at our planet.
This view looks toward Saturn from about 31 degrees above the ring plane. The image was taken with the Cassini spacecraft wide-angle camera on Jan. 22, 2017 using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 939 nanometers.
The view was obtained at a distance of approximately 560,000 miles (900,000 kilometers) from Saturn. Image scale is 33 miles (54 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 Cassini's Grand Finale, visit: https://saturn.jpl.nasa.gov/grandfinale
For more information about the Cassini-Huygens mission visit: https://saturn.jpl.nasa.gov and www.nasa.gov/cassini
The Cassini imaging team homepage is at https://ciclops.org
Credit: NASA/JPL-Caltech/Space Science Institute
Image Date: January 22, 2017
Release Date: May 8, 2017#NASA #Astronomy #Science #Space #Saturn #Atmosphere #Hexagon #Planet #GrandFinale #SolarSystem #Exploration #Cassini #Spacecraft #JPL #Pasadena #California #UnitedStates #ESA #ASI #History #STEM #Education
This enhanced color view of Jupiter’s south pole was created by citizen scientist Gabriel Fiset using data from the JunoCam instrument on NASA’s Juno spacecraft. Oval storms dot the cloudscape. Approaching the pole, the organized turbulence of Jupiter’s belts and zones transitions into clusters of unorganized filamentary structures, streams of air that resemble giant tangled strings.The image was taken on Dec. 11, 2016 at 9:44 a.m. PST (12:44 p.m. EST), from an altitude of about 32,400 miles (52,200 kilometers) above the planet’s beautiful cloud tops.Credit: NASA/JPL-Caltech/SwRI/MSSS/Gabriel FisetImage Date: December 11, 2016 Release Date: May 5, 2017#NASA #Astronomy #Science #Space #Jupiter #Planet #Juno #Spacecraft #JunoCam #Atmosphere #Clouds #Exploration #SolarSystem #Technology #Engineering #JPL #Pasadena #California #USA #UnitedStates #LockheedMartin #MSFC #Marshall #SwRI #STEM #Education #CitizenScience
May 4, 2017: "Today’s mission was the seventh Arianespace dual-launch carrying two satellites built by Thales Alenia Space. SGDC and KOREASAT-7 were built in Thales Alenia Space’s plants in Cannes and Toulouse (France), using the Spacebus 4000C4 and 4000B2 platforms, respectively. These platforms are perfectly adapted to Arianespace’s launcher family."
"Arianespace and Thales Alenia Space have developed a very solid and fruitful relationship since the launch of Meteosat-F2 on June 19, 1981. SGDC and KOREASAT-7 are the 147th and 148th Thales Alenia Space satellites to be launched by Arianespace."
"Eight more Thales Alenia Space satellites are to be launched by Arianespace in the coming years."
Shortly after the announcement of the orbital injection of the two satellites, Stéphane Israël, CEO of Arianespace, said: 'With this second successful launch of the year by Ariane 5, and the 78th successful mission in a row by our heavy launcher, Arianespace proudly gives our Brazilian and South Korean customers the benefits of our excellent launch services. We are honored by the confidence expressed today by Visiona Tecnologia Espacial, which chose us for its first satellite on behalf of the operator Telebras and the Brazilian government; as well as that of the South Korean operator KTsat, for whom we have launched three satellites since 1999."
“Congratulations to all our partners for this 92nd launch of an Ariane 5: Thales Alenia Space, which built both satellites launched on the same Ariane for the seventh time since 1991; our primary shareholder, Airbus Safran Launchers, and the entire European launcher industry for the reliability and availability of this heavy launcher; ESA, which provides essential support for the Ariane program; CNES/CSG, our ground segment companies and all staff at the space center, who continue to work alongside us as we go from success to success. And, of course, I would like to congratulate everybody at Arianespace for this successful launch, the fourth of the year.”
"The SGDC satellite was built by Thales Alenia Space using a Spacebus 4000C4 platform. Its payload comprises 57 Ka and X-band transponders. Positioned at 75° West, SGDC will provide telecommunications, internet access and civil and military communications services for Brazil. The satellite weighed 5,735 kg. at launch and offers a design life exceeding 18 years."
"KOREASAT-7 was built by Thales Alenia Space using a Spacebus 4000B2 platform. Its payload comprises 30 Ku-band transponders, plus Ka-band transponders. Positioned at 116° East, KOREASAT-7 will supply telecommunications and broadcasting services for South Korea, the Philippines, Indonesia, India and the Indochinese peninsula. The satellite weighed 3,680 kg. at launch and offers a design life exceeding 15 years."
About Arianespace
"Arianespace uses space to make life better on Earth by providing launch services for all types of satellites into all orbits. It has orbited more than 550 satellites since 1980, using its family of three launchers, Ariane, Soyuz and Vega, from launch sites in French Guiana (South America) and Baikonur, Kazakhstan. Arianespace is headquartered in Evry, near Paris, and has a technical facility at the Guiana Space Center, Europe’s Spaceport in French Guiana, plus local offices in Washington, D.C., Tokyo and Singapore. Arianespace is a subsidiary of Airbus Safran Launchers, which holds 74% of its share capital, with the balance held by 17 other shareholders from the European launcher industry."
Credit: Arianespace
Release Date: May 4, 2017#ESA #Arianespace #Space #Rocket #Ariane5 #Ariane #HeavyLaunch #Satellite #Telecommunications #KOREASAT7 #KTsat #한국 #SGDC #Telebras #Brazil #Brasil #ThalesAlenia
The NASA Visualization Explorer App is now available to users with Android devices running version 5.0 or higher.
You can download the app for free from the Google Play store or from NASA's website: https://nasaviz.gsfc.nasa.gov/
The app features data visualizations developed by NASA's Scientific Visualization Studio, Earth Observatory, Science@NASA and others, that show current research from NASA's study of Earth, the moon, the sun, our solar system and the universe beyond.
Stories are released every other Monday, and with the Android version release, put NASA's exploration of our world and universe into the hands of more people with a smartphone or tablet. Each story features a high-resolution movie or still image and short text to put it into context. Recent features have included viewing the world's carbon dioxide in 3-D, erupting water plumes on Jupiter and the path of this summer's total solar eclipse across North America.
Originally launched in 2011 for the iPad, the app became available on all iOS devices in 2014. User requests prompted development of the Android version, which will run on Android 5.0 and higher.
The current release is a beta version, and while users do not yet have all the features of the iOS versions, they will be able to browse all 525 current stories, receive new stories and share them via social media. NASA is looking forward to receiving input from users as we continue refining the Android version. Users can send feedback in the main menu of the app or through the developer email found on the NASA Viz App's Google Play webpage.
Credit: NASA's Scientific Visualization Studio at Goddard Space Flight Center
Release Date: May 2, 2017#NASA #Earth #Science #Space #Technology #Visualization #Smartphone #Tablet #App #Android #Google #GooglePlay #Explorer #Students #Teachers #Goddard #GSFC #Greenbelt #Maryland #UnitedStates #STEM #Education
Assembled using raw uncalibrated infrared (IR3), red, and violet filtered images taken by the Cassini spacecraft on May 3rd, 2017.
For more information about Cassini's Grand Finale, visit: https://saturn.jpl.nasa.gov/grandfinale
Credit: NASA/JPL-Caltech/SSI/Kevin M. Gill
Image Date: May 3, 2017
Release Date: May 4, 2017#NASA #Astronomy #Science #Space #Saturn #Rings #Planet #GrandFinale #SolarSystem #Exploration #Cassini #Spacecraft #JPL #Pasadena #California #UnitedStates #ESA #ASI #History #STEM #Education
Image: Six billion light years away!
May 4, 2017: The NASA/ESA Hubble Telescope has peered across six billion light years of space to resolve extremely faint features of the galaxy cluster Abell 370 that have not been seen before. Imaged here in stunning detail, Abell 370 is part of the Frontier Fields program which uses massive galaxy clusters to study the mysteries of dark matter and the very early Universe.
Six billion light-years away in the constellation Cetus (the Sea Monster), Abell 370 is made up of hundreds of galaxies [1]. Already in the mid-1980s higher-resolution images of the cluster showed that the giant luminous arc in the lower left of the image was not a curious structure within the cluster, but rather an astrophysical phenomenon: the gravitationally lensed image of a galaxy twice as far away as the cluster itself. Hubble helped show that this arc is composed of two distorted images of an ordinary spiral galaxy that just happens to lie behind the cluster.
Abell 370’s enormous gravitational influence warps the shape of spacetime around it, causing the light of background galaxies to spread out along multiple paths and appear both distorted and magnified. The effect can be seen as a series of streaks and arcs curving around the centre of the image. Massive galaxy clusters can therefore act like natural telescopes, giving astronomers a close-up view of the very distant galaxies behind the cluster—a glimpse of the Universe in its infancy, only a few hundred million years after the Big Bang.
This image of Abell 370 was captured as part of the Frontier Fields programme, which used a whopping 630 hours of Hubble observing time, over 560 orbits of the Earth. Six clusters of galaxies were imaged in exquisite detail, including Abell 370 which was the very last one to be finished. An earlier image of this object—using less observation time and therefore not recording such faint detail —was published in 2009.
During the cluster observations, Hubble also looked at six “parallel fields”, regions near the galaxy clusters which were imaged with the same exposure times as the clusters themselves. Each cluster and parallel field were imaged in infrared light by the Wide Field Camera 3 (WFC3), and in visible light by the Advanced Camera for Surveys (ACS).
The Frontier Fields programme produced the deepest observations ever made of galaxy clusters and the magnified galaxies behind them. These observations are helping astronomers understand how stars and galaxies emerged out of the dark ages of the Universe, when space was dark, opaque, and filled with hydrogen.
Studying massive galaxy clusters like Abell 370 also helps with measuring the distribution of normal matter and dark matter within such clusters [heic1506]. By studying its lensing properties, astronomers have determined that Abell 370 contains two large, separate clumps of dark matter, contributing to the evidence that this massive galaxy cluster is actually the result of two smaller clusters merging together.
Now that the observations for the Frontier Fields program are complete, astronomers can use the full dataset to explore the clusters, their gravitational lensing effects and the magnified galaxies from the early Universe in full detail.
Credit: NASA, ESA/Hubble, HST Frontier Fields
Release Date: May 4, 2017#NASA #Hubble #Astronomy #Science #Space #Abell370 #Galaxy #Cluster #Cetus #Cosmos #Universe #Telescope #STScI #Goddard #GSFC #ESA #STEM #Education
Krupac Crater also hosts some of the most impressive recurring slope lineae on equatorial Mars outside of Valles Marineris. This image was acquired by the High Resolution Imaging Science Experiment (HiRISE) instrument aboard the Mars Reconnaissance Orbiter (MRO).
Although large gullies (ravines) are concentrated at higher latitudes, there are gullies on steep slopes in equatorial regions. An enhanced-color closeup shows part of the rim and inner slope of Krupac Crater located just 7.8 degrees south of the equator.
The colors of the gully deposits match the colors of the eroded source materials. Krupac is a relatively young impact crater, but exposes ancient bedrock. Krupac Crater also hosts some of the most impressive recurring slope lineae (RSL) on equatorial Mars outside of Valles Marineris.
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 Caltech in Pasadena, California, manages the Mars Reconnaissance Orbiter Project for NASA's Science Mission Directorate, Washington.
Image Credit: NASA/JPL/University of Arizona
Caption Credit: Alfred McEwen
Release Date: May 3, 2017
#NASA #Mars #Space #Astronomy #Science #Crater #Krupac #Gullies #RecurringSlopeLineae #RSL #Geology #Landscape #Terrain #Geoscience #MRO #Reconnaissance #Orbiter #Spacecraft #HiRISE #Camera #JPL #STEM #Education
May 1, 2017: An astronaut aboard the International Space Station centered this photograph on the largest group of lights in the northeastern United States. New York City and Newark, New Jersey, lie at the center of a string of city lights stretching roughly 300 kilometers (200 miles) from Philadelphia to Hartford. The characteristic shape of Long Island, during night and daylight overpasses, is one of the most recognizable features to an astronaut looking at the Northeast coast.
Night-light intensity indicates population densities, a phenomenon well-known to urban geographers. An important pattern is the progressive decline of population density away from the cores of the largest cities. Lower population densities appear in the southern counties of New Jersey, though the barrier islands are defined by narrow shoreline developments. Some rural areas in the photo have fewer lights than shipping lanes of the North Atlantic Ocean.
A network of thin lines indicates highways and main roads—which can be difficult to discern in daylight images—radiating from the major cities. One of the brightest lines is Interstate 95, which crosses the entire image from a point west of Philadelphia through New York—where it is overwhelmed by city lights—and along the coast of Connecticut.
Image Credit: Astronaut photograph ISS050-E-29655 was acquired on January 10, 2017, with a Nikon D4 digital camera using a 45 millimeter lens, and is provided by the ISS Crew Earth Observations Facility and the Earth Science and Remote Sensing Unit, Johnson Space Center. The image was taken by a member of the Expedition 50 crew. The image has been cropped and enhanced to improve contrast, and lens artifacts have been removed. The International Space Station Program supports the laboratory as part of the ISS National Lab to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public.
Caption Credit: Andi Hollier, Hx5, JETS Contract at NASA-JSC
Instrument(s): ISS - Digital Camera
Image Date: January 10, 201
Release Date: May 1, 2017
#NASA #ESA #ISS #Earth #Science #UnitedStates #Night #Orbit #Astronauts #ShaneKimbrough #PeggyWhitson #ThomasPesquet #Proxima #Expedition50 #Technology #Photography #JSC #CNES #France #Europe #OverviewEffect #OrbitalPerspective #STEM #Education
May 1, 2017: NASA’s James Webb Space Telescope has successfully passed the center of curvature test, an important optical measurement of Webb’s fully assembled primary mirror prior to cryogenic testing, and the last test held at NASA's Goddard Space Flight Center in Greenbelt, Maryland, before the spacecraft is shipped to NASA’s Johnson Space Center in Houston for more testing.
After undergoing rigorous environmental tests simulating the stresses of its rocket launch, the Webb telescope team at Goddard analyzed the results from this critical optical test and compared it to the pre-test measurements. The team concluded that the mirrors passed the test with the optical system unscathed.
“The Webb telescope is about to embark on its next step in reaching the stars as it has successfully completed its integration and testing at Goddard. It has taken a tremendous team of talented individuals to get to this point from all across NASA, our industry and international partners, and academia,” said Bill Ochs, NASA’s Webb telescope project manager. “It is also a sad time as we say goodbye to the Webb Telescope at Goddard, but are excited to begin cryogenic testing at Johnson.”
Rocket launches create high levels of vibration and noise that rattle spacecraft and telescopes. At Goddard, engineers tested the Webb telescope in vibration and acoustics test facilities that simulate the launch environment to ensure that functionality is not impaired by the rigorous ride on a rocket into space.
Before and after these environmental tests took place, optical engineers set up an interferometer, the main device used to measure the shape of the Webb telescope’s mirror. An interferometer gets its name from the process of recording and measuring the ripple patterns that result when different beams of light mix and their waves combine or “interfere.”
Waves of visible light are less than a thousandth of a millimeter long and optics on the Webb telescope need to be shaped and aligned even more accurately than that to work correctly. Making measurements of the mirror shape and position by lasers prevents physical contact and damage (scratches to the mirror). So, scientists use wavelengths of light to make tiny measurements. By measuring light reflected off the optics using an interferometer, they are able to measure extremely small changes in shape or position that may occur after exposing the mirror to a simulated launch or temperatures that simulate the subfreezing environment of space.
During a test conducted by a team from Goddard, Ball Aerospace of Boulder, Colorado, and the Space Telescope Science Institute in Baltimore, temperature and humidity conditions in the clean room were kept incredibly stable to minimize fluctuations in the sensitive optical measurements over time. Even so, tiny vibrations are ever-present in the clean room that cause jitter during measurements, so the interferometer is a “high-speed” one, taking 5,000 “frames” every second, which is a faster rate than the background vibrations themselves. This allows engineers to subtract out jitter and get good, clean results on any changes to the mirror's shape.
“Some people thought it would not be possible to measure beryllium mirrors of this size and complexity in a clean room to these levels but the team was incredibly ingenious in how they performed these measurements and the results give us great confidence we have a fantastic primary mirror,” said Lee Feinberg, Webb’s telescope optical element manager.
The Webb telescope will be shipped to Johnson for end-to-end optical testing in a vacuum at its extremely cold operating temperatures. Then it will continue on its journey to Northrop Grumman Aerospace Systems in Redondo Beach, California, for final assembly and testing prior to launch in 2018.
The James Webb Space Telescope is the world’s most advanced space observatory. This engineering marvel is designed to unravel some of the greatest mysteries of the universe, from discovering the first stars and galaxies that formed after the big bang to studying the atmospheres of planets around other stars. It is a joint project of NASA, ESA (the European Space Agency) and the Canadian Space Agency.
For more information about the Webb Telescope mirrors, visit: www.jwst.nasa.gov or www.nasa.gov/webb
Article Credit: NASA Goddard
Image Credit: NASA/Chris Gunn
Release Date: May 1, 2017
#NASA #Astronomy #Science #Space #Telescope #JWST #JamesWebb #Exoplanets #Planets #Astrophysics #Cosmos #Universe #ESA #CSA #Goddard #GSFC #JSC #Johnson #UnitedStates #STScI #STEM #Education
ESA Astronaut Thomas Pesquet of France: "Finally a picture of Paris by day, during the weekend too. A metropolis that extends far beyond the camera frame. Much to explore in this picture! I hope everybody can spot something they recognize, famous monuments, streets they lived in, restaurants where great meals were eaten, museums and more that Paris has on offer."
"Enfin un passage au-dessus de Paris en journée, le weekend et par beau temps ! La ville rentre à peine dans mon cadre… Chacun y trouvera j’espère sa rue, un monument préféré, une gare de passage, des souvenirs"
Credit: ESA/NASA
Image Date: April 20, 2017
#NASA #ESA #ISS #Earth #Planet #Science #Paris #Day #EarthObservation #Astronaut #ThomasPesquet #Proxima #Expedition51 #Technology #Photography #JSC #CNES #France #Europe #OverviewEffect #OrbitalPerspective #STEM #Education
Satellite view of clouds and sunglint over islands in the Pacific Ocean
May 1, 2017: Areas near the equator are frequently cloudy, obscuring the view of Earth’s surface from space. April 7, 2017, was no different. On that day, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this natural-color image of clouds over the Gilbert Islands. The remote island chain is part of the Republic of Kiribati, and straddles the equator in the central Pacific Ocean.
These clouds, however, were not your typical tropical rainstorm. Instead, the parallel “roll clouds” were likely influenced by the development of Tropical Cyclone Cook to the south. At the time, Cook was strengthening near Vanuatu and heading toward New Caledonia.
“As far as tropical cyclones go, we believe that they are a nearly ideal environment for roll formation,” said Ralph Foster, an atmospheric scientist at the University of Washington. The extreme wind shear associated with cyclones generates additional turbulence in the already turbulent layer of air near Earth’s surface. According to Foster, the turbulent flow in this layer “self-organizes,” forming long rolls of counter-rotating air.
More precisely, the atmosphere has alternating clockwise and counter-clockwise circulation. In between the overturning circulations are updrafts and downdrafts. If conditions are right for clouds to form, clouds will grow in the updraft zone and be suppressed in the downdraft. The resulting linear cloud features can persist for hours.
But just because these convective rolls are happening in the atmosphere does not necessarily mean there will be clouds. “The clouds themselves contribute little to the roll dynamics,” Foster said. “We think of these clouds as convenient flow visualizations.”
The hazy, vertical strip obscuring part of the image is sunlight mirrored from the ocean surface, known as “sunglint.”
The Gilbert Islands are a chain of sixteen atolls and coral islands in the Pacific Ocean about halfway between Papua New Guinea and Hawaii. (Source: Wikipedia)
Annotated image and further reading: NASA's Earth Observatory
Tour Earth's Clouds From Space
Image Credit: NASA image by Jeff Schmaltz, LANCE/EOSDIS Rapid Response
Caption Credit: Kathryn Hansen
Image Date: April 7, 2017
Release Date: May 1, 2017
#NASA #Earth #Science #Space #Satellite #Atmosphere #Clouds #Sunglint #GilbertIslands #Pacific #Ocean #Atolls #Islands #EarthObservation #RemoteSensing #Terra #MODIS #GSFC #Goddard #Greenbelt #Maryland #UnitedStates #STEM #Education
This image from Hubble’s Wide Field Camera 3 (WFC3) shows a spiral galaxy NGC 5917, perhaps best known for its intriguing interactions with its neighboring galaxy MCG-01-39-003 (not visible here, but located off the bottom right of the frame—as seen here).
Mass is often confused with weight, but they are very different things. Mass is the very substance of an object and is something one always has, no matter the location. If you fly to the Moon and experience low-gravity conditions, your mass has not changed at all. What has actually changed is your weight, because weight is a force caused by the gravitational attraction of another massive body. Gravity is how objects with mass “talk” to one another. People do weigh less on the Moon, but not because they have lost any body mass—the mass of the Moon is less than that of the Earth, so it exerts a smaller gravitational pull on them.
Understanding mass is vital when it comes to understanding why objects behave the way they do in space. Without mass “talking” via gravity, the planets would not orbit the Sun, and galaxies would not interact as NGC 5917 does with its neighbor. Galaxy interactions can lead to very interesting effects; the galaxies can steal mass—in form of stars, dust and gas—from one another, distort and warp one another’s shape, or trigger immense waves of new star formation. Sometimes, a galactic duo interact so strongly that they end up colliding and merging completely. Unfortunately, if NGC 5917 is destined to merge with its celestial neighbour, it will happen much too far into the future for us to enjoy the spectacle.
Credit: ESA/Hubble & NASA
Release Date: May 1, 2017
#NASA #Hubble #Astronomy #Science #Galaxy #Spiral #NGC5917 #MCG0139003 #Gravity #Mass #Cosmos #Universe #HST #Telescope #ESA #GSFC #Goddard #STScI #History #STEM #Education
ESA Astronaut Thomas Pesquet of France: "The end of Proxima nears, less than five weeks to go. So much work to do and not enough time fully appreciate the Bahamas blue. The current return date is June 2, but like everything in spaceflight it can change."
"La fin de la mission Proxima approche : plus que cinq semaines. Encore tellement de boulot... et pas assez de temps pour graver dans ma mémoire les bleus des Bahamas ! Le retour sur Terre est prévu pour le 2 juin - mais dans le spatial le calendrier peut changer..."
The Bahamas, officially the Commonwealth of the Bahamas, is an island country of the Lucayan Archipelago consisting of more than 700 islands, cays, and islets in the Atlantic Ocean; north of Cuba and Hispaniola (Haiti and the Dominican Republic); northwest of the Turks and Caicos Islands; southeast of the U.S. state of Florida and east of the Florida Keys. Its capital is Nassau on the island of New Providence. (Source: Wikipedia)
Credit: ESA/NASA
Capture Date: April 21, 2017
#NASA #ESA #ISS #Earth #Planet #Science #Bahamas #Island #Archipelago #Atlantic #Ocean #EarthObservation #Astronaut #ThomasPesquet #Proxima #Expedition51 #Technology #Photography #JSC #CNES #France #Europe #OverviewEffect #OrbitalPerspective #STEM #Education
The event horizon is in the middle of the image, and the shadow can be seen with a rotating accretion disk surrounding it.
In general relativity, an event horizon is a boundary in spacetime beyond which events cannot affect an outside observer. In layman's terms, it is defined as the shell of "points of no return", i.e., the points at which the gravitational pull becomes so great as to make escape impossible, even for light. An event horizon is most commonly associated with black holes. Light emitted from inside the event horizon can never reach the outside observer. Likewise, any object approaching the horizon from the observer's side appears to slow down and never quite pass through the horizon, with its image becoming more and more redshifted as time elapses. This means that the wavelength is getting longer as the object moves away from the observer. The traveling object, however, experiences no strange effects and does, in fact, pass through the horizon in a finite amount of proper time. (Source: Wikipedia)
Credit: Bronzwaer/Davelaar/Moscibrodzka/Falcke/Radboud University
Acknowledgement: European Southern Observatory (ESO)
#ESO #Astronomy #Science #Space #BlackHole #Supermassive #Simulation #EventHorizon #Theory #Relativity #GeneralRelativity #Einstein #Astrophysics #Physics #Cosmos #Universe #STEM #Education #Visualization
