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
This infographic shows a simulation of the outflow (bright red) from a black hole and the accretion disk around it, with simulated images of the three potential shapes of the event horizon’s shadow. General relativity (GR, also known as the general theory of relativity or GTR) is the geometric theory of gravitation published by Albert Einstein in 1915 and the current description of gravitation in modern physics. General relativity generalizes special relativity and Newton's law of universal gravitation, providing a unified description of gravity as a geometric property of space and time, or spacetime. In particular, the curvature of spacetime is directly related to the energy and momentum of whatever matter and radiation are present. The relation is specified by the Einstein field equations, a system of partial differential equations.(Source: Wikipedia)
Credit: ESO/N. Bartmann/A. Broderick/C.K. Chan/D. Psaltis/F. OzelRelease Date: April 28, 2017
#ESO #Astronomy #Science #Space #BlackHole #Supermassive #Simulation #AccretionDisk #Theory #Relativity #GeneralRelativity #Einstein #Astrophysics #Physics #Cosmos #Universe #STEM #Education #Infographic #Visualization
On February 21, 2017, the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite captured this natural-color image of a large dust plume streaming from North Africa toward Europe and the Atlantic Ocean. Additional images of the storm, acquired on February 22 and February 23, are available.
Image Credit: NASA image by Jeff Schmaltz, LANCE/EOSDIS Rapid Response
Caption Credit: Adam Voiland
Image Date: February 21, 2017
Instrument(s): Suomi NPP - VIIRS
#NASA #Earth #Science #Satellite #Africa #NorthAfrica #Atmosphere #Planet #Dust #Storms #Weather #SuomiNPP #VIIRS #Education #STEM
Feb. 22, 2017: NASA's Spitzer Space Telescope has revealed the first known system of seven Earth-size planets around a single star. Three of these planets are firmly located in the habitable zone, the area around the parent star where a rocky planet is most likely to have liquid water.
The discovery sets a new record for greatest number of habitable-zone planets found around a single star outside our solar system. All of these seven planets could have liquid water – key to life as we know it – under the right atmospheric conditions, but the chances are highest with the three in the habitable zone.
“This discovery could be a significant piece in the puzzle of finding habitable environments, places that are conducive to life,” said Thomas Zurbuchen, associate administrator of the agency’s Science Mission Directorate in Washington. “Answering the question ‘are we alone’ is a top science priority and finding so many planets like these for the first time in the habitable zone is a remarkable step forward toward that goal.”
At about 40 light-years (235 trillion miles) from Earth, the system of planets is relatively close to us, in the constellation Aquarius. Because they are located outside of our solar system, these planets are scientifically known as exoplanets.
This exoplanet system is called TRAPPIST-1, named for The Transiting Planets and Planetesimals Small Telescope (TRAPPIST) in Chile. In May 2016, researchers using TRAPPIST announced they had discovered three planets in the system. Assisted by several ground-based telescopes, including the European Southern Observatory's Very Large Telescope, Spitzer confirmed the existence of two of these planets and discovered five additional ones, increasing the number of known planets in the system to seven.
The new results were published Wednesday in the journal Nature, and announced at a news briefing at NASA Headquarters in Washington.
Using Spitzer data, the team precisely measured the sizes of the seven planets and developed first estimates of the masses of six of them, allowing their density to be estimated.
Based on their densities, all of the TRAPPIST-1 planets are likely to be rocky. Further observations will not only help determine whether they are rich in water, but also possibly reveal whether any could have liquid water on their surfaces. The mass of the seventh and farthest exoplanet has not yet been estimated – scientists believe it could be an icy, "snowball-like" world, but further observations are needed.
"The seven wonders of TRAPPIST-1 are the first Earth-size planets that have been found orbiting this kind of star," said Michael Gillon, lead author of the paper and the principal investigator of the TRAPPIST exoplanet survey at the University of Liege, Belgium. "It is also the best target yet for studying the atmospheres of potentially habitable, Earth-size worlds."
In contrast to our sun, the TRAPPIST-1 star – classified as an ultra-cool dwarf – is so cool that liquid water could survive on planets orbiting very close to it, closer than is possible on planets in our solar system. All seven of the TRAPPIST-1 planetary orbits are closer to their host star than Mercury is to our sun. The planets also are very close to each other. If a person was standing on one of the planet’s surface, they could gaze up and potentially see geological features or clouds of neighboring worlds, which would sometimes appear larger than the moon in Earth's sky.
The planets may also be tidally locked to their star, which means the same side of the planet is always facing the star, therefore each side is either perpetual day or night. This could mean they have weather patterns totally unlike those on Earth, such as strong winds blowing from the day side to the night side, and extreme temperature changes.
Spitzer, an infrared telescope that trails Earth as it orbits the sun, was well-suited for studying TRAPPIST-1 because the star glows brightest in infrared light, whose wavelengths are longer than the eye can see. In the fall of 2016, Spitzer observed TRAPPIST-1 nearly continuously for 500 hours. Spitzer is uniquely positioned in its orbit to observe enough crossing – transits – of the planets in front of the host star to reveal the complex architecture of the system. Engineers optimized Spitzer’s ability to observe transiting planets during Spitzer’s “warm mission,” which began after the spacecraft’s coolant ran out as planned after the first five years of operations.
"This is the most exciting result I have seen in the 14 years of Spitzer operations," said Sean Carey, manager of NASA's Spitzer Science Center at Caltech/IPAC in Pasadena, California. "Spitzer will follow up in the fall to further refine our understanding of these planets so that the James Webb Space Telescope can follow up. More observations of the system are sure to reveal more secrets.”
Following up on the Spitzer discovery, NASA's Hubble Space Telescope has initiated the screening of four of the planets, including the three inside the habitable zone. These observations aim at assessing the presence of puffy, hydrogen-dominated atmospheres, typical for gaseous worlds like Neptune, around these planets.
In May 2016, the Hubble team observed the two innermost planets, and found no evidence for such puffy atmospheres. This strengthened the case that the planets closest to the star are rocky in nature.
"The TRAPPIST-1 system provides one of the best opportunities in the next decade to study the atmospheres around Earth-size planets," said Nikole Lewis, co-leader of the Hubble study and astronomer at the Space Telescope Science Institute in Baltimore, Maryland. NASA's planet-hunting Kepler space telescope also is studying the TRAPPIST-1 system, making measurements of the star's minuscule changes in brightness due to transiting planets. Operating as the K2 mission, the spacecraft's observations will allow astronomers to refine the properties of the known planets, as well as search for additional planets in the system. The K2 observations conclude in early March and will be made available on the public archive.
Spitzer, Hubble, and Kepler will help astronomers plan for follow-up studies using NASA's upcoming James Webb Space Telescope, launching in 2018. With much greater sensitivity, Webb will be able to detect the chemical fingerprints of water, methane, oxygen, ozone, and other components of a planet's atmosphere. Webb also will analyze planets' temperatures and surface pressures – key factors in assessing their habitability.
NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate. Science operations are conducted at the Spitzer Science Center, at Caltech, in Pasadena, California. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colorado. Data are archived at the Infrared Science Archive housed at Caltech/IPAC. Caltech manages JPL for NASA.
For more information on the TRAPPIST-1 system, visit: https://exoplanets.nasa.gov/trappist1
Credit: NASA/JPL
Release Date: February 22, 2017
#NASA #Astronomy #Exoplanets #Trappist #Earth #Astrobiology #Science #Water #Exploration #Discovery #JPL #Spitzer #STEM #Education
January 27, 2017: When NASA’s Commercial Crew Astronauts make their first trip to the International Space Station aboard Boeing’s Starliner spacecraft, they’ll be outfitted in new custom-designed spacesuits. Astronauts Eric Boe and Suni Williams tried on the new suits, which were unveiled Jan. 25. In addition to meeting NASA’s requirements for safety and functionality, the new design weighs less and is more comfortable than earlier versions.
Also, Expedition 52/53 News Conference, Cargo Ship Departs the ISS, 50th Anniversary of Apollo 1 Fire and more!
Watch on Friends of NASA Google+:
https://plus.google.com/113507009175485747967/posts/ddHF9YZf81a
Credit: NASA
Duration: 3 minutes
Release Date: January 27, 2017
