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Aleksey R.
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Icy Hearts: A heart-shaped calving front of a glacier in Greenland (left) and Plutoâs frozen plains (right). Credits: NASA/Maria-Jose Viñas and NASA/APL/SwRI
From deep below the soil at Earthâs polar regions to Plutoâs frozen heart, ice exists all over the solar systemâŠand beyond. From right here on our home planet to moons and planets millions of miles away, weâre exploring ice and watching how it changes. Hereâs 10 things to know:
An Antarctic ice sheet. Credit: NASA
Ice sheets are massive expanses of ice that stay frozen from year to year and cover more than 6 million square miles. On Earth, ice sheets extend across most of Greenland and Antarctica. These two ice sheets contain more than 99 percent of the planetâs freshwater ice. However, our ice sheets are sensitive to the changing climate.
Data from our GRACE satellites show that the land ice sheets in both Antarctica and Greenland have been losing mass since at least 2002, and the speed at which theyâre losing mass is accelerating.
Earthâs polar oceans are covered by stretches of ice that freezes and melts with the seasons and moves with the wind and ocean currents. During the autumn and winter, the sea ice grows until it reaches an annual maximum extent, and then melts back to an annual minimum at the end of summer. Sea ice plays a crucial role in regulating climate â itâs much more reflective than the dark ocean water, reflecting up to 70 percent of sunlight back into space; in contrast, the ocean reflects only about 7 percent of the sunlight that reaches it. Sea ice also acts like an insulating blanket on top of the polar oceans, keeping the polar wintertime oceans warm and the atmosphere cool.
Some Arctic sea ice has survived multiple years of summer melt, but our research indicates thereâs less and less of this older ice each year. The maximum and minimum extents are shrinking, too. Summertime sea ice in the Arctic Ocean now routinely covers about 30-40 percent less area than it did in the late 1970s, when near-continuous satellite observations began. These changes in sea ice conditions enhance the rate of warming in the Arctic, already in progress as more sunlight is absorbed by the ocean and more heat is put into the atmosphere from the ocean, all of which may ultimately affect global weather patterns.
Snow extends the cryosphere from the poles and into more temperate regions.
Snow and ice cover most of Earthâs polar regions throughout the year, but the coverage at lower latitudes depends on the season and elevation. High-elevation landscapes such as the Tibetan Plateau and the Andes and Rocky Mountains maintain some snow cover almost year-round. In the Northern Hemisphere, snow cover is more variable and extensive than in the Southern Hemisphere.
Snow cover the most reflective surface on Earth and works like sea ice to help cool our climate. As it melts with the seasons, it provides drinking water to communities around the planet.
Tundra polygons on Alaskaâs North Slope. As permafrost thaws, this area is likely to be a source of atmospheric carbon before 2100. Credit: NASA/JPL-Caltech/Charles Miller
Permafrost is soil that stays frozen solid for at least two years in a row. It occurs in the Arctic, Antarctic and high in the mountains, even in some tropical latitudes. The Arcticâs frozen layer of soil can extend more than 200 feet below the surface. It acts like cold storage for dead organic matter â plants and animals.
In parts of the Arctic, permafrost is thawing, which makes the ground wobbly and unstable and can also release those organic materials from their icy storage. As the permafrost thaws, tiny microbes in the soil wake back up and begin digesting these newly accessible organic materials, releasing carbon dioxide and methane, two greenhouse gases, into the atmosphere.
Two campaigns, CARVE and ABoVE, study Arctic permafrost and its potential effects on the climate as it thaws.
Did you know glaciers are constantly moving? The masses of ice act like slow-motion rivers, flowing under their own weight. Glaciers are formed by falling snow that accumulates over time and the slow, steady creep of flowing ice. About 10 percent of land area on Earth is covered with glacial ice, in Greenland, Antarctica and high in mountain ranges; glaciers store much of the worldâs freshwater.
Our satellites and airplanes have a birdâs eye view of these glaciers and have watched the ice thin and their flows accelerate, dumping more freshwater ice into the ocean, raising sea level.
The nitrogen ice glaciers on Pluto appear to carry an intriguing cargo: numerous, isolated hills that may be fragments of water ice from Plutoâs surrounding uplands. NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Plutoâs most famous feature â that heart! â is stone cold. First spotted by our New Horizons spacecraft in 2015, the heartâs western lobe, officially named Sputnik Planitia, is a deep basin containing three kinds of ices â frozen nitrogen, methane and carbon monoxide.
Models of Plutoâs temperatures show that, due the dwarf planetâs extreme tilt (119 degrees compared to Earthâs 23 degrees), over the course of its 248-year orbit, the latitudes near 30 degrees north and south are the coldest places â far colder than the poles. Ice would have naturally formed around these latitudes, including at the center of Sputnik Planitia.
New Horizons also saw strange ice formations resembling giant knife blades. This âbladed terrainâ contains structures as tall as skyscrapers and made almost entirely of methane ice, likely formed as erosion wore away their surfaces, leaving dramatic crests and sharp divides. Similar structures can be found in high-altitude snowfields along Earthâs equator, though on a very different scale.
This image, combining data from two instruments aboard our Mars Global Surveyor, depicts an orbital view of the north polar region of Mars. Credit: NASA/JPL-Caltech/MSSS
Mars has bright polar caps of ice easily visible from telescopes on Earth. A seasonal cover of carbon dioxide ice and snow advances and retreats over the poles during the Martian year, much like snow cover on Earth.
This animation shows a side-by-side comparison of CO2 ice at the north (left) and south (right) Martian poles over the course of a typical year (two Earth years). This simulation isnât based on photos; instead, the data used to create it came from two infrared instruments capable of studying the poles even when theyâre in complete darkness. This data were collected by our Mars Reconnaissance Orbiter, and Mars Global Surveyor. Credit: NASA/JPL-Caltech
During summertime in the planetâs north, the remaining northern polar cap is all water ice; the southern cap is water ice as well, but remains covered by a relatively thin layer of carbon dioxide ice even in summertime.
Scientists using radar data from our Mars Reconnaissance Orbiter found a record of the most recent Martian ice age in the planetâs north polar ice cap. Research indicates a glacial period ended there about 400,000 years ago. Understanding seasonal ice behavior on Mars helps scientists refine models of the Red Planetâs past and future climate.
Wispy fingers of bright, icy material reach tens of thousands of kilometers outward from Saturnâs moon Enceladus into the E ring, while the moonâs active south polar jets continue to fire away. Credit: NASA/JPL/Space Science Institute
Saturnâs rings and many of its moons are composed of mostly water ice â and one of its moons is actually creating a ring. Enceladus, an icy Saturnian moon, is covered in âtiger stripes.â These long cracks at Enceladusâ South Pole are venting its liquid ocean into space and creating a cloud of fine ice particles over the moonâs South Pole. Those particles, in turn, form Saturnâs E ring, which spans from about 75,000 miles (120,000 kilometers) to about 260,000 miles (420,000 kilometers) above Saturnâs equator. Our Cassini spacecraft discovered this venting process and took high-resolution images of the system.
Jets of icy particles burst from Saturnâs moon Enceladus in this brief movie sequence of four images taken on Nov. 27, 2005. Credit: NASA/JPL/Space Science Institute
View of a small region of the thin, disrupted, ice crust in the Conamara region of Jupiterâs moon Europa showing the interplay of surface color with ice structures. Credit: NASA/JPL/University of Arizona
The icy surface of Jupiterâs moon Europa is crisscrossed by long fractures. During its flybys of Europa, our Galileo spacecraft observed icy domes and ridges, as well as disrupted terrain including crustal plates that are thought to have broken apart and âraftedâ into new positions. An ocean with an estimated depth of 40 to 100 miles (60 to 150 kilometers) is believed to lie below that 10- to 15-mile-thick (15 to 25 km) shell of ice.
The rafts, strange pits and domes suggest that Europaâs surface ice could be slowly turning over due to heat from below. Our Europa Clipper mission, targeted to launch in 2022, will conduct detailed reconnaissance of Europa to see whether the icy moon could harbor conditions suitable for life.
The image shows the distribution of surface ice at the Moonâs south pole (left) and north pole (right), detected by our Moon Mineralogy Mapper instrument. Credit: NASA
In the darkest and coldest parts of our Moon, scientists directly observed definitive evidence of water ice. These ice deposits are patchy and could be ancient. Most of the water ice lies inside the shadows of craters near the poles, where the warmest temperatures never reach above -250 degrees Fahrenheit. Because of the very small tilt of the Moonâs rotation axis, sunlight never reaches these regions.
A team of scientists used data from a our instrument on Indiaâs Chandrayaan-1 spacecraft to identify specific signatures that definitively prove the water ice. The Moon Mineralogy Mapper not only picked up the reflective properties weâd expect from ice, but was able to directly measure the distinctive way its molecules absorb infrared light, so it can differentiate between liquid water or vapor and solid ice.
With enough ice sitting at the surface â within the top few millimeters â water would possibly be accessible as a resource for future expeditions to explore and even stay on the Moon, and potentially easier to access than the water detected beneath the Moonâs surface.
With an estimated temperature of just 50K, OGLE-2005-BLG-390L b is the chilliest exoplanet yet discovered. Pictured here is an artistâs concept. Credit: NASA
OGLE-2005-BLG-390Lb, the icy exoplanet otherwise known as Hoth, orbits a star more than 20,000 light years away and close to the center of our Milky Way galaxy. Itâs locked in the deepest of deep freezes, with a surface temperature estimated at minus 364 degrees Fahrenheit (minus 220 Celsius)!
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Scientists' consensus is that a layer of liquid water exists beneath Europa's surface, and that heat from tidal flexing allows the subsurface ocean to remain liquid.
Europa's surface temperature averages about 110 K (â160 °C; â260 °F) at the equator and only 50 K (â220 °C; â370 °F) at the poles, keeping Europa's icy crust as hard as granite. The first hints of a subsurface ocean came from theoretical considerations of tidal heating (a consequence of Europa's slightly eccentric orbit and orbital resonance with the other Galilean moons). Galileo imaging team members argue for the existence of a subsurface ocean from analysis of Voyager and Galileo images.
The most dramatic example is "chaos terrain", a common feature on Europa's surface that some interpret as a region where the subsurface ocean has melted through the icy crust.
The thin-ice model suggests that Europa's ice shell may be only a few kilometers thick. However, most planetary scientists conclude that this model considers only those topmost layers of Europa's crust that behave elastically when affected by Jupiter's tides.
The Hubble Space Telescope acquired an image of Europa in 2012 that was interpreted to be a plume of water vapour erupting from near its south pole The image suggests the plume may be 200Â km (120Â mi) high, or more than 20 times the height of Mt. Everest.
So far, there is no evidence that life exists on Europa, but Europa has emerged as one of the most likely locations in the Solar System for potential habitability. Life could exist in its under-ice ocean, perhaps in an environment similar to Earth's deep-ocean hydrothermal vents. Even if Europa lacks volcanic hydrothermal activity, a 2016 NASA study found that Earth-like levels of hydrogen and oxygen could be produced through processes related to serpentinization and ice-derived oxidants, which do not directly involve volcanism.
In 2015, scientists announced that salt from a subsurface ocean may likely be coating some geological features on Europa, suggesting that the ocean is interacting with the seafloor. This may be important in determining if Europa could be habitable. The likely presence of liquid water in contact with Europa's rocky mantle has spurred calls to send a probe there.
Europa Clipper is an interplanetary mission in development by NASA comprising an orbiter. Set for a launch in October 2024, the spacecraft is being developed to study the Galilean moon Europa through a series of flybys while in orbit around Jupiter.
The Europa Lander is a proposed astrobiology mission concept by NASA to Europa, an icy moon of Jupiter. If funded and developed as a large strategic science mission, it would be launched in 2027 to complement the studies by the Europa Clipper orbiter mission and perform analyses on site. NASA's budget for fiscal year 2021 neither mandates nor allocates any funds to the mission leaving its future uncertain.
The objectives of the mission are to search for biosignatures at the subsurface â10 cm, to characterize the composition of non-ice near-subsurface material, and determine the proximity of liquid water and recently erupted material near the lander's location.
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On Aug. 21, all of North America will experience a solar eclipse.
If skies are clear, eclipse-watchers will be able to see a partial solar eclipse over several hours, and some people â within the narrow path of totality â will see a total solar eclipse for a few moments.
Itâs never safe to look at the Sun, and an eclipse is no exception. During a partial eclipse (or on any regular day) you must use special solar filters or an indirect viewing method to watch the Sun.
If you have solar viewing glasses, check to make sure theyâre safe and undamaged before using them to look at the Sun. Make sure you put them on before looking up at the Sun, and look away before removing them. Eclipse glasses can be used over your regular eyeglasses, but they should never be used when looking through telescopes, binoculars, camera viewfinders, or any other optical device.
If you donât have eclipse glasses, you can still watch the eclipse indirectly! You can make a pinhole projector out of a box, or use any other object with tiny holes â like a piece of cardstock with a hole, or your outstretched, interlaced fingers â to project an image of the partially eclipsed Sun onto the ground.
Of course, if itâs cloudy (or youâd just rather stay inside), you can watch the whole thing online with us at nasa.gov/eclipselive. Tune in starting at noon ET.
If youâre in the path of totality, there will be a few brief moments when it is safe to look directly at the eclipse. Only once the Moon has completely covered the Sun and there is no light shining through is it safe to look at the eclipse. Make sure you put your eclipse glasses back on or return to indirect viewing before the first flash of sunlight appears around the Moonâs edge.
A solar eclipse happens when the Moon passes directly between the Sun and Earth, casting its shadow down on Earthâs surface. The path of totality â where the Moon completely covers the Sun â is traced out by the Moonâs inner shadow, the umbra. People within the Moonâs outer shadow, the penumbra, can see a partial eclipse.
The Moonâs orbit around Earth is tilted by about five degrees, meaning that its shadow usually doesnât fall on Earth. Only when the Moon lines up exactly between the Sun and Earth do we see an eclipse.
Though the Sun is about 400 times wider than the Moon, it is also about 400 times farther away, making their apparent sizes match up almost exactly. This is what allows the Moon to block out the Sunâs bright face, while revealing the comparatively faint, pearly-white corona.
Eclipses are a beautiful sight to see, and theyâre also helpful for our scientists, so weâre funding eleven ground-based science investigations to learn more about the Sun and Earth.
Total solar eclipses reveal the innermost regions of the Sunâs atmosphere, the corona. Though itâs thought to house the processes that kick-start much of the space weather that can influence Earth, as well as heating the whole corona to extraordinarily high temperatures, we canât study this region at any other time. This is because coronagraphs â the instruments we use to study the Sunâs atmosphere by creating artificial eclipses â must cover up much of the corona, as well as the Sunâs face in order to produce clear images.
Eclipses also give us the chance to study Earthâs atmosphere under uncommon conditions: the sudden loss of solar radiation from within the Moonâs shadow. Weâll be studying the responses of both Earthâs ionosphere â the region of charged particles in the upper atmosphere â and the lower atmosphere.
Learn all about the Aug. 21 eclipse at eclipse2017.nasa.gov, and follow @NASASun on Twitter and NASA Sun Science on Facebook for more. Watch the eclipse through the eyes of NASA at nasa.gov/eclipselive starting at 12 PM ET on Aug. 21.Â
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
âIf man had no eternal consciousness, if, at the bottom of everything, there were merely a wild seething force producing everything, both large and trifling, in the storm of dark passions, if the bottomless void that nothing can fill underlay all things, what would life be but despair?â
- Albert Camus, quoting Kierkegaard in âSysiphosâ
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This region of star formation features a giant bubble that is blowing out from the middle of this image due to winds flowing off young stars. Chandra X-ray Observatory data (purple and pink) show this superbubble of hot gas, while Hubble Space Telescope data (orange and light blue) reveals the gas and dust in the system.
Image credit: Judy Schmidt
12 hours of exposure on the Whirlpool Galaxy revealing the faint dust hiding through out space
via reddit
Images of Saturn, Tethys, and Mimas taken by Cassini on July 16 2005.
Credit: NASA/JPL-Caltech/SSI/CICLOPS/Kevin M. Gill
 My ambition is handicapped by laziness. -C. Bukowski   Me gustan las personas desesperadas con mentes rotas y destinos rotos. Estån llenos de sorpresas y explosiones. -C. Bukowski. I love cats. Born in the early 80's, raised in the 90's. I like Nature, Autumn, books, landscapes, cold days, cloudy Windy days, space, Science, Paleontology, Biology, Astronomy, History, Social Sciences, Drawing, spending the night watching at the stars, Rick & Morty. I'm a lazy ass.
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