What is the true long-term threat of Near Earth Objects? NASA defines "potentially hazardous" as a Near Earth Object that will pass within .05 AU from Earth and is at least 140 meters in diameter. (http://neo.jpl.nasa.gov/neo/pha.html) But consider the damage left by a 30-meter object in the famed Siberian impact of 1908: "Recent scientific studies by meteorite researcher Christopher Chyba have estimated that the Tunguska event may have been caused by the explosion of a stony meteroid about 30 meters in diameter traveling at about 15 km/s. Compare the energy released by such an object with that of an atomic bomb such as those dropped on Japan in World War II." See: http://www.psi.edu/projects/siberia/siberia.html The truth is no one really knows how many asteroids this size or larger are out there. According to NASA sources, the population breaks down as follows: 100 meters in diameter: 300,000 500 meters in diameter: 10,000 Over one kilometer in diameter: 500-1,000 The good news is that eight projects are at work to search for them, including NASA s NEO-Wise space telescope, and more are coming on line soon. The bad news is that fewer than 8,000 of these have been discovered so far.

This video is modeled in the classic tradition of P.T. Barnum, offering a collection of oddities for your viewing pleasure. So enter the Curiosity Shop for a compilation of facts and beautiful moon images taken by the Cassini spacecraft in orbit around Saturn since 2004, set to Edvard Grieg s Piano Concerto in A Minor, Op. 16 II. Adagio. This video is produced in honor of the recent Cassini Spacecraft Mission extension through September 2017. Take a gander at Gigantic Titan to your left. Feel free to ogle bright Enceladus to your right, reflecting close to 100 percent of the light that hits its surface. Don t be afraid to eyeball Mimas and her craters. That s what she s there for! Saturn has the second most moons of planets in the solar system. Second, only to Jupiter. September 27th, 2010 marked the end of the Cassini Equinox Mission, which was over the last 2 years, and the beginning of the Cassini Solstice Mission. The extension to takes the spacecraft to September 2017, a couple months past Saturn s Northern summer solstice in May 2017. Cassini has done a great deal to extend our knowledge of Saturn and it s moons as well as delivered some of the most gorgeous photos taken in the Solar System; Photos of Saturn, Saturn s rings and Saturn s moons. This video pictures just a few of the many photos. Fact Sheet: Mimas Diameter: averages 396 km Orbital Radius: 185,520 km Orbital Period: 22 hours and 37 minutes Mass: 37,500,000,000 megatonnes Mimas and Rhea are widely considered the most heavily cratered bodies in the Solar System Enceladus Diameter: about 500 km Orbital Radius: 238,020 kilometers Orbital Period: 1.37 Days Mass: 70,000,000,000 megatonnes It is postulated that Enceladus is heated by a tidal mechanism similar to Jupiter s moon Io and many signs point to a liquid core even though it should ve frozen aeons ago. It is the most reflective object in the solar system. Tethys Diameter: 1,066 km Orbital Radius: 294,660km Orbital Period: 1.89 earth days Mass: 627,000,000,000 megatonnes Odysseus Crater (named for a Greek warrior king in Homer s two great works, The Iliad and The Odyssey) dominates the Tethyan western hemisphere. Odysseus Crater is 400 kilometers in-diameter (almost 250 miles). That diameter is nearly two-fifths of Tethys itself. Dione Diameter: 1,123 km Orbital Radius: 377,400 km Orbital Period: 2.7 earth days Mass: 1,100,000,000,000 megatonnes Cassini showed Dione s bright wisps to be bright canyon ice walls (some of them several hundred meters high), probably caused by subsidence cracking. The walls are bright because darker material falls off them, exposing bright water ice. Rhea Diameter: 1,528 km Average Distance: 527,040 km Orbital Period: 4.52 Earth days Mass: 2,310,000,000,000 megatonnes Titan Equatorial Radius: 2,575 km Orbital Distance: 1,221,830 km Orbital Period: 15.95 Earth days Mass: 134,550,000,000,000 megatonnes Recent results from the Cassini mission suggest that hydrogen and acetylene are depleted at the surface of Titan. Both results are still preliminary, but the findings are interesting for astrobiology. A paper published 5 years ago suggested that methane-based (rather than water-based) life -- ie, organisms called methanogens -- on Titan could consume hydrogen, acetylene, and ethane. The measured depletion of these compounds could mean the existence of these life forms on the surface. Hyperion Average diameter: 270 km Mass: 800,000,000 megatonnes Orbital Distance: 1,481,100 km Orbital Period: 21.28 Earth days Hyperion is the largest known irregular (nonspherical) body in the Solar System. Iapetus Equatorial Radius: 735.5 km Orbital Distance: 3,561,300 km Orbital Period: 79.33 Earth days Mass: 1,600,000,000,000 megatonnes The September 2007 Cassini flyby of Iapetus showed that thermal segregation is probably the most responsible for Iapetus having a darker hemisphere. Iapetus has a very slow rotation, longer than 79 days. Such a slow rotation means that the daily temperature cycle is very long, so long that the dark material can absorb heat from the Sun and warm up. Phoebe Diameter: 220 km Orbital Distance: 12,952,000 km Orbital Period: about 18 months Mass: 400,000,000 megatonnes Unlike most major moons orbiting Saturn, Phoebe is very dark and reflects only 6 percent of the sunlight it receives. Its darkness and irregular, retrograde orbit suggest Phoebe is most likely a captured object.

The longer a telescope spends looking at a target, the more sensitive the observations become, and the deeper we can look into space. But to get the full picture of what s happening in the Universe, astronomers also need observations at a range of different wavelengths, requiring different telescopes. These are the key ideas behind the Great Observatories Origins Deep Survey, or GOODS for short. The GOODS project unites the world s most advanced observatories, these include ESO s Very Large Telescope, the NASA/ESA Hubble Space Telescope, the Spitzer Space Telescope, the Chandra X-ray Observatory and many more, each making extremely deep observations of the distant Universe, across the electromagnetic spectrum. By combining their powers and observing the same piece of the sky, the GOODS observatories are giving us a unique view of the formation and evolution of galaxies across cosmic time, and mapping the history of the expansion of the Universe. Now, this is not the first time that telescopes have been used to give us extremely deep views of the cosmos. For example, the Hubble Deep Field is a very deep image of a small piece of sky in the northern constellation of Ursa Major. This revealed thousands of distant galaxies despite the fact that the whole field is actually only a tiny speck of the sky, about the size of a grain of sand held at arm s length. Now, with GOODS, many different observatories have brought their powers to bear on two larger targets, one centered on the original Hubble Deep Field in the northern sky, and one centred on a different deep target, the Chandra Deep Field South, in the southern sky. The main GOODS fields are each 30 times larger than the Hubble Deep Field, and additional observations cover an area the size of the full Moon. These areas of the sky were already some of the most extensively explored, and so the combination of existing archival data and many new, dedicated observations gives us an unprecedented view of of the history of galaxies.

A mashed up and blended version of a recent series of NASA public service announcements featuring James Cameron and imagery from Avatar. The premise of Avatar, you ll recall, was that humans journeyed to Alpha Centauri having already ruined their own planet.

From NASA Astrophysics... a supercomputer simulation shows how alien astronomers might have seen the formation of our solar system. Dust ground off icy bodies in the Kuiper Belt, the cold-storage zone that includes Pluto and millions of other objects, creates a faint infrared disk potentially visible to alien astronomers looking for planets around the sun. Neptune s gravitational imprint on the dust is always detectable in new simulations of how this dust moves through the solar system. By ramping up the collision rate, the simulations show how the distant view of the solar system might have changed over its history.

What s the hottest place in the universe? What s it like inside a Black Hole? This video climbs the power scales of the universe, from the coldest and bleakest reaches of our galaxy on out to the hottest and most violent places known. How and where do Earth and humanity fit within the immensely powerful scales that define our universe? All across the immense reaches of time and space, energy is being exchanged, transferred, released, in a great cosmic pinball game we call our universe. To see how energy stitches the cosmos together, and how we fit within it, we now journey through the cosmic power scales of the universe, from atoms nearly frozen to stillness. To Earth s largest explosions. From stars colliding, exploding, to distant centers of power so strange, and violent, they challenge our imaginations. Today, energy is very much on our minds, as we search for ways to power our civilization and serve the needs of our citizens. But what is energy? Where does it come from? And where do we stand within the great power streams that shape time and space? Energy comes from a Greek word for activity or working. In physics, it s simply the property or the state of anything in our universe that allows it to do work. Whether it s thermal, kinetic, electro-magnetic, chemical, or gravitational. The 19th century German scientist Hermann von Helmholtz found that all forms of energy are equivalent, that one form can be transformed into any other. The laws of physics say that in a closed system - such as our universe - energy is conserved. It may be converted, concentrated, or dissipated, but it s never lost. Humans today generate about two and a half trillion watts of electrical power. How does that stack up to the power generated by planet Earth? Deep inside our planet, the radioactive decay of elements such as uranium and thorium generates 44 trillion watts of power. As this heat rises to the surface, it drives the movement of Earth s crustal plates, and powers volcanoes. Remarkably, that s just a fraction of the energy released by a large hurricane in the form of rain. At the storm s peak, it can rise to 600 trillion watts. A hurricane draws upon solar heat collected in tropical oceans in the summer. You have to jump another power of ten to reach the estimated total heat flowing through Earth s atmosphere and oceans from the equator to the poles, and another two to get the power received by the Earth from the sun, at 174 quadrillion watts. Believe it or not, there s one human technology that has exceeded this level. The AN602 hydrogen bomb was detonated by the Soviet Union on October 30, 1961. It unleashed some 1400 times the combined power of the Nagasaki and Hiroshima bombs. With a blast yield of up to 57,000 tons of TNT, it generated 5.3 trillion trillion watts, if only for a tiny fraction of a second. That s 5.3 Yottawatts, a term that will come in handy as we now begin to ascend the power scales of the universe. To Nikolai Kardashev, a Level 2 civilization would achieve a constant energy output 80 times higher than the Russian superbomb. That s equivalent to the total luminosity of our sun, a medium-sized star that emits 375 yottawatts. However, in the grand scheme of things, our sun is but a cold spark in a hot universe. Look up into Southern skies and you ll see the Large Magellanic Cloud, a satellite galaxy of our Milky Way. Deep within is the brightest star yet discovered. R136a1 is 10 million times brighter than the sun. Now if that star happened to go supernova, at its peak, it would blast out photons with a luminosity of around 500 billion yottawatts. To advance to a level three civilization, you have to marshal the power of an entire galaxy. The Milky Way, with about two hundred billion stars, has an estimated total luminosity of 3 trillion yottawatts, a three followed by 36 zeros. To boldly go beyond Level 3, a civilization would need to marshal the power of a quasar. A quasar is about a thousand times brighter than our galaxy. Here is where cosmic power production enters a whole new realm, based on the physics of extreme gravity. It was Isaac Newton who first defined gravity as the force that pulls the apple down, and holds the earth in orbit around the sun. Albert Einstein redefined it in his famous General Theory of Relativity. Gravity isn t simply the attraction of objects like stars and planets, he said, but a distortion of space and time, what he called space-time. If space-time is like a fabric, he said, gravity is the warping of this fabric by a massive object like a star. A planet orbits a star when it s caught in this warped space, like a ball spinning around a roulette wheel.

The latest gem from ESA s HubbleCast. The Hubble Space Telescope has inspired widespread awe in the beauty and complexity of the Universe. But with its stunning gallery of images, Hubble has also become embedded in popular culture.

Watch for our 20-minute COSMIC JOURNEYS episode. It explores the power scales of the universe, from the least to the most energetic events and places known to science. All across the immense reaches of time and space, energy is being exchanged, transferred, released... in a great cosmic pinball game we call our universe. To see how energy stitches the cosmos together, and how we fit within it, we now journey through the cosmic scales of power... From atoms... nearly frozen to stillness... To Earth s largest explosions. From stars.... colliding... exploding... To distant centers of power so strange... and violent... they challenge our imaginations.

Astronomers working with the super planet finding HARPS instrument at the La Silla Observatory in Chile, have discovered a remarkable extrasolar planetary system that has some striking similarities to our own Solar System. At least five planets are orbiting the Sun-like star HD 10180, and the regular pattern of their orbits is similar to that observed for our neighbouring planets. One of the new extrasolar worlds could be only 1.4 times the mass of the Earth, making it the least massive exoplanet ever found.

A Titan 3/Centaur rocket launched NASA s Viking 1 spacecraft on a 505-million-mile journey to Mars on Aug. 20, 1975. Viking 2 followed three weeks later. Each mission included both an orbiter and a lander, and all four components accomplished successes. On July 20, 1976, the Viking 1 lander returned the first photograph taken on the surface of Mars. That lander in a region called Chryse Planitia operated until Nov. 13, 1982. The Viking 2 lander operated in the Utopia Planitia region from Sept. 3, 1976 to April 11, 1980. The orbiters sent home images of the entire planet at resolutions of 300 meters or less per pixel.

A giant 97-square mile slab of ice recently broke off from Greenland s Petermann Glacier. Is this a sign that the climate is gradually changing? What does it mean in a global context? NASA scientists are training their satellites on these dynamic rivers of ice and factoring them into climate models designed to understand and predict where we re going.

The Fermi Gamma Ray Space Telescope picked up a whole new type of cosmic explosion: a ultra high-intensity explosion coming from the surface of a white dwarf star. The finding stunned observers and theorists alike because it overturns a long-standing notion that such novae explosions lack the power for such high-energy emissions. In March, Fermi s Large Area Telescope (LAT) detected gamma rays -- the most energetic form of light -- from the nova for 15 days. Scientists believe that the emission arose as a million-mile-per-hour shock wave raced from the site of the explosion. A nova is a sudden, short-lived brightening of an otherwise inconspicuous star. The outburst occurs when a white dwarf in a binary system erupts in an enormous thermonuclear explosion.

A beautiful nugget from Spitzer s "Hidden Universe." Behind a dark veil of dust in the constellation Sagittarius, a lurking dragon has been revealed by the infrared eye of NASA s Spitzer Space Telescope. The red dots along its dark filaments are baby stars forming at a furious rate. The dark Dragon appears to fly away from M17, its brightly glowing neighbor known alternately as the Omega or Swan nebula. Oddly, astronomers have found that both the Dragon and the Swan are forming roughly the same numbers of stars. If so, why should they look so different from one another? The answer may be that dragons, rather than ugly ducklings, grow up to become swans. While the Dragon is forming fairly large type B stars, only in the Swan do we find the very largest O stars. Their brilliant glare illuminates and disperses the dust, creating a nebula that is equally vivid in infrared and visible light. The gas and dust clouds in this region appear to be passing through the Sagittarius spiral arm, a kind of gravitational traffic jam. Astronomers have long believed clouds will bunch up when they enter a spiral arm, triggering the gravitational collapse needed to form stars. When the first generation of smaller stars form in the Dragon, they seem to further compress the nearby dust. This enables a second generation of even more massive O stars to form and light up the area, destroying the surrounding dust clouds. Further downstream from the Swan, a cluster of O stars sits at the center of a blown-out bubble. This is likely the fading remains of an older nebula, now largely dispersed as it exits the other side of the spiral arm. In this one picture, Spitzer has captured a snapshot of the evolution of a star-forming region. From Dragon, to Swan, to bubble, it heralds a new generation of Milky Way stars.

See more lethal animals on World s Deadliest, Fridays at 10 PM, only on Nat Geo Wild! ➡ Subscribe: http://bit.ly/NatGeoSubscribe About National Geographic: National Geographic is the world s premium destination for science, exploration, and adventure. Through their world-class scientists, photographers, journalists, and filmmakers, Nat Geo gets you closer to the stories that matter and past the edge of what s possible. Get More National Geographic: Official Site: http://bit.ly/NatGeoOfficialSite Facebook: http://bit.ly/FBNatGeo Twitter: http://bit.ly/NatGeoTwitter Instagram: http://bit.ly/NatGeoInsta Looking like a cross between a rat and an octopus, the star-nosed mole would be a good candidate for the title of world s weirdest-looking creature. Nat Geo Wild : http://animals.nationalgeographic.com/wild/shows The World s Weirdest Creature? | National Geographic https://youtu.be/SsvR4r1fCAQ National Geographic https://www.youtube.com/natgeo

While orbiting Saturn for the last six years, NASA s Cassini spacecraft has kept a close eye on the collisions and disturbances in the gas giant s rings. They provide the only nearby natural laboratory for scientists to see the processes that must have occurred in our early solar system, as planets and moons coalesced out of disks of debris. New images from Cassini show icy particles in Saturn s F ring clumping into giant snowballs as the moon Prometheus makes multiple swings by the ring. The gravitational pull of the moon sloshes ring material around, creating wake channels that trigger the formation of objects as large as 20 kilometers (12 miles) in diameter. Saturn s thin, kinky F ring was discovered by NASA s Pioneer 11 spacecraft in 1979. Prometheus and Pandora, the small "shepherding" moons on either side of the F ring, were discovered a year later by NASA s Voyager 1. In the years since, the F ring has rarely looked the same twice, and scientists have been watching the impish behavior of the two shepherding moons for clues. Prometheus, the larger and closer to Saturn of the two moons, appears to be the primary source of the disturbances. At its longest, the potato-shaped moon is 148 kilometers (92 miles) across. It cruises around Saturn at a speed slightly greater than the speed of the much smaller F ring particles, but in an orbit that is just offset. As a result of its faster motion, Prometheus laps the F ring particles and stirs up particles in the same segment once in about every 68 days. "Some of these objects will get ripped apart the next time Prometheus whips around," Murray said. "But some escape. Every time they survive an encounter, they can grow and become more and more stable." Cassini scientists using the ultraviolet imaging spectrograph previously detected thickened blobs near the F ring by noting when starlight was partially blocked. These objects may be related to the clumps seen by Murray and colleagues. The newly-found F ring objects appear dense enough to have what scientists call "self-gravity." That means they can attract more particles to themselves and snowball in size as ring particles bounce around in Prometheus s wake, Murray said. The objects could be about as dense as Prometheus, though only about one-fourteenth as dense as Earth. What gives the F ring snowballs a particularly good chance of survival is their special location in the Saturn system. The F ring resides at a balancing point between the tidal force of Saturn trying to break objects apart and self-gravity pulling objects together. One current theory suggests that the F ring may be only a million years old, but gets replenished every few million years by moonlets drifting outward from the main rings. However, the giant snowballs that form and break up probably have lifetimes of only a few months. The new findings could also help explain the origin of a mysterious object about 5 to 10 kilometers (3 to 6 miles) in diameter that Cassini scientists spotted in 2004 and have provisionally dubbed S/2004 S 6. This object occasionally bumps into the F ring and produces jets of debris. "The new analysis fills in some blanks in our solar system s history, giving us clues about how it transformed from floating bits of dust to dense bodies," said Linda Spilker, Cassini project scientist at NASA s Jet Propulsion Laboratory in Pasadena, Calif. "The F ring peels back some of the mystery and continues to surprise us."

Take a DEEP BREATH before watching this ESOCast mashup with Dr. J. The Sun is setting behind Cerro Paranal in the Chilean Atacama desert. While astronomers get ready to observe with ESO s Very Large Telescope, Nature prepares for her own grand display. As night falls over the desert, the southern sky reveals its nocturnal beauty, leaving the spectator in silent amazement. Some people, however, don t just stare at the spectacle. With great skill, they record these unique moments for everyone to see - they are the photographers of the night. Anyone who has been up at night in a remote, high place such as at one of ESO s observatories in Chile may have been lucky enough to experience the splendid view of the myriad stars shining brightly from the heavens. It is a both a dream and a challenge for a photographer to capture an image of this incredible view. Today we will focus on three ESO staff members, who, during their free time, produce outstanding astrophotography. By publishing their results on the internet they share their enthusiasm for the astonishing wonders of the southern skies with a wider audience. Yuri Beletsky is an ESO Fellow and astronomer at the Paranal Observatory. When not observing with the world s most advanced telescope, the VLT, he actively lives out his passion for taking pictures of the southern sky. "I like the night sky, I like stars and the night sky is so beautiful, you can see millions of stars and astrophotography is the best way to show the people what actually stars are, so taking this picture I share my passion with people and I am showing the sky then." Over time, Yuri has produced many spectacular images of Paranal against the wonderful backdrop of the night sky. A laser beam shooting out of one of the VLT _s Unit Telescopes. The bright constellation of the Southern Cross. The Pipe Nebula with its picturesque dust lane crossing the Milky Way. Sunlight reflected by small particles of dust lying in between the planets causes the faint zodiacal light. Paranal is an ideal site for astrophotographers as it offers crystal-clear, extremely dark skies with perfect weather conditions on about 320 nights per year. Gerhard Hüdepohl, an electronic engineer at Paranal knows about the photographic benefits of the VLT _s site. Gerhard, who is also a renowned photographer of Chile s landscape, combines the beauty of the Atacama desert with the shining Milky Way in a unique way. "My favourite type of photography is landscape photography and in particular images of the landscape at night, showing the Milky Way in the night sky here in the Atacama desert. And here at Paranal I can have the telescopes as a nice foreground and the stars and the night sky as a background". The bright plane of our Milky Way as it arches above the VLT. An image like this can only be obtained under top-notch stargazing conditions, such as those offered at Paranal. Like Yuri, Gerhard has also produced a spectacular series of images showing the VLT with its laser beam and the night sky. "I am always trying to show Paranal from new, fresh points of view, different angles, different times of the day, so I am always thinking about new ideas. So that is my plan for the future". Astrophotography is very demanding. The photographer has to stay out in the dark and in the chill of the night for many hours. Sometimes it can take several nights of painstaking work in these tough conditions to obtain just one image and the equipment must always function flawlessly. Stéphane Guisard is the head of the optical group at Paranal. His astrophotography benefits from his professional expertise as an optical engineer specialising in telescopes. "I take pictures of galaxies and nebulae with a telescope, but I also like to take wide-field images of the sky with a terrestrial foreground. I like to share the beauty of the sky and the Universe with people." This photographic mosaic of the central parts of our galactic home is just one example of Stéphane s work. Taken with an amateur telescope coupled to a CCD camera, the image combines about 1200 photos for a total exposure time of around 250 hours. Stéphane has also produced a spectacular series of timelapse sequences at the Paranal site. Producing such sequences is quite a challenge as the images must be taken at regular intervals, and all the parameters must match perfectly to obtain the sensation of the moving firmament. There is no doubt that Yuri, Gerhard and Stéphane will continue to produce stunning images of the starry skies above Paranal. The wonderful quality of the images is a testament to the splendour of the night sky at ESO s Paranal Observatory. By sharing their work, these three astrophotographers have brought their magnificent view of the southern sky to a wider audience.

NASA JPL scientists look for Earthly examples of the terrain features they ve been seeing on Saturn s moon Titan, including the dry landscapes of Death Valley, California. From NASA s Jet Propulsion Laboratory. Since we re probably never going to get to the surface of Titan and be able to pick up the rocks and take samples of the liquid, we wanted to be able to understand a place that we can get to, and then draw conclusions about Titan. We believe that geology is geology everywhere. So we ve come to Death Valley, to Racetrack Playa. It s a dry lake right now, but it s a lake nonetheless; so we can look for similar pieces of evidence. The reason we do that is we can crawl around Death Valley and measure things. We could find out what s happening and find out what causes that evidence to occur. And it s just like a detective game from there on. So whenever you have a high thing next to a low thing, you can be sure that something s going to happen. Nature likes to even itself out. On Ontario Lacus, we have high things right next to low things. So the rainfall is going to move the material from the high to the low and it s going to form these same alluvial fans where material washes out from the gully like it does here, and it s going to flow the material down to the lakebed. At Ontario Lacus, there are pieces of bedrock like this, only probably made out of water ice, that make fingers that extend down into the lake. It s as though the lake had risen up and flooded those valleys. Now this is a much smaller example than we see on Ontario Lacus, but it tells us that the level of the water is what has made this into a finger, not the finger itself. On Titan, we think that the lakes are filled by seasonal drainages. Sometimes, those drainages make cross-hatch patterns that look like gullies. So we looked on Earth for a place that has those cross-hatch gullies, and here we find it at Racetrack Playa. Water that comes down from those hills flows in infrequent but violent thunderstorms out onto Racetrack Playa. As the rainfall comes down closer to the playa, on Titan, they form deltas, something like the Mississippi Delta out there. This is a dry lakebed, so what happens is that the gravel just gets pushed out onto the lakebed. And that s a clue, that what s happening on Titan is a fluid, not a dry lakebed. So by studying the relationship between the evidence and the events here in Death Valley,where we can measure them, we can connect that same set of evidence to the events that might have happened on Titan. It s important because if we re going to find life somewhere else in the universe, it has to have something in common with the once place that we know has life, and that s here.

Check out the unusual visual style in this adaptation of the ground-breaking "Science on a Sphere" production, including depictions of Earth. From NASA and NOAA, with additional images from ESA Hubble. We perceive light--we see it—but what we see and what it means are not the same. Without context, detail means nothing. Oh, there are so many factors at play here: what wavelengths of light can we see, how well can our brains take what we see and turn it into something we understand? And also, how do we compare ourselves to the thing we re observing? What tools do we use to help us capture information? How do we turn light into data, data into pixels, pixels into meaning? Start with a planet. For example, Earth. And as long as we re at it, let s tip the Earth to spin properly on its axis. Now, recall our original points of light. Our idea. These are satellites in orbit. Satellites collect data as the Earth rotates beneath them. Think of satellites as paint brushes working in reverse: instead of painting planets with light, satellites collect light reflected from planets below. With enough data we can paint a world. Data that make this image come from instruments on two NASA satellites called AQUA and TERRA. These instruments see the Earth in what we might regard as "natural color." They can also see certain events as they happen. There, splattered like white paint on a blue canvas, something important: Hurricane Katrina. These satellites are only two of many that can see hurricanes. The stripes you see building up come from a unique spacecraft called TRMM. Among the many remarkable things TRMM can do, it can look inside hurricanes like nothing else in the world. See for yourself. TRMM sees the actual body of the beast in three dimensions. Orange and red zones indicate higher rainfall rates. Cloud spires called hot towers drive the storm s greedy grab for energy. The Earth changes. It breathes. And it surprises. Though we live on a planet largely covered by water, we often forget that huge tracts are frozen solid. Let s change the perspective. Ice covers much of the world. The eternally frozen parts are called the Cryosphere. It s the planet s thermostat, and a hydrological warehouse, and in terms of a changing climate, it s the canary in a coalmine. You may live your whole life and never visit these places, but these places will affect your life nonetheless. You know this place. The Moon. Earth s closest neighbor is little more than a beautiful stranger across an airless room. There are mysteries here and answers. And, like love, perhaps, destiny. Back on Earth, day and night change like moods, with points of light pricking the darkness like vaguely remembered dreams. City lights shine into space at night, like ancient campfires, like candles of civilization. No other place beyond the Earth shows signs of life like this, or shows signs of life at all. But we re looking. Before we can find life elsewhere, we need to be good at reading its signs at home first. And on Earth, life is everywhere. This is the living Earth: the biosphere. Phytoplankton bloom in vast oceanic fields. Land plants pulse rhythmically with seasonal growth. Together, these sound the global heartbeat, the pulse of life powered by the sun. The Sun. All energy on Earth comes from the sun. The Moon...the Earth...the Sun: celestial spheres we see and feel everyday. But in our solar neighborhood, there are other places, too. Fabulous places. Mysterious places. As a tourist destination, Mars has an impressive brochure. The longest, deepest canyon in the solar system. A volcano so high it s peak climbs above most of the Martian atmosphere. Nothing like these places exists on Earth. Nothing. This is from a NASA mission called WMAP. If the whole universe were a person, this would be its first baby picture. There are no stars here, no galaxies, certainly no planets. But there is energy. The rest came soon enough, once the new kid could collect herself. This is the universe we see today. It s a lively place. That s a gamma ray burst, spotted by NASA s "SWIFT" satellite. These cosmic blasts have long puzzled scientists. They may be stars collapsing in upon themselves, or two densely packed remnants of stars merging together. But in either case, scientists believe they herald the births of black holes. They re the most powerful explosions in the universe after the Big Bang. And they seem to happen all the time, as often as once a day. We look outwards as much as we look inwards, for if there is any certainty in the journey of knowledge it s that travel in any direction can lead to the same destination. We see only what we look for, and in space and on Earth we seek the wisdom to ask the right questions.

Natural and human-caused change captured in these extraordinary image sequences covering years and decades of time. Read about the individual sequences on: http://earthobservatory.nasa.gov/Features/WorldOfChange/index.php Earth is constantly changing. Some changes are a natural part of the climate system, such as the seasonal expansion and contraction of the Arctic sea ice pack. The responsibility for other changes, such as the Antarctic ozone hole, falls squarely on humanity s shoulders. NASA s World of Change series documents how our planet s land, oceans, atmosphere, and Sun are changing over time. Mt. St. Helens The devastation of the May 18, 1980, eruption of Mt. St. Helens and the gradual recovery of the surrounding landscape is documented in this series of satellite images from 1979--2009. Aral Sea A massive irrigation project in the Kyzylkum Desert of central Asia has devastated the Aral Sea over the past 50 years. These images show the continued decline of the Southern Aral Sea in the past decade, as well as the first steps of recovery in the Northern Aral Sea in recent years. Dubai To expand the possibilities for beachfront tourist development, Dubai, part of the United Arab Emirates, undertook a massive engineering project to create hundreds of artificial islands along its Persian Gulf coastline. Yellowstone In 1988, wildfires raced through Yellowstone National Park, consuming hundreds of thousands of acres. This series of Landsat images tracks the landscape s slow recovery through 2008. Southeast Australia Drought has taken a severe toll on croplands in Southeast Australia during many years this decade. Colorado River Combined with human demands, a multi-year drought in the Upper Colorado River Basin caused a dramatic drop in the Colorado River s Lake Powell in the early part of the 2000 decade. The lake began to recover in the latter part of the decade, but as of May 2010, it was still less than 60 percent of capacity. Antarctica In the early 1980s, scientists began to realize that CFCs were creating a thin spot—a hole—in the ozone layer over Antarctica every spring. This series of satellite images shows the ozone hole on the day of its maximum depth each year from 1979 through 2008. Amazon The state of Rondônia in western Brazil is one of the most deforested parts of the Amazon. This series shows deforestation on the frontier in the northwestern part of the state between 2000 and 2008. Larsen B Ice Shelf In early 2002, scientists monitoring daily satellite images of the Antarctic Peninsula watched in amazement as almost the entire Larsen B Ice Shelf splintered and collapsed in just over one month. They had never witnessed such a large area disintegrate so rapidly. West Virginia Based on data from NASA s Landsat 5 satellite, these natural-color (photo-like) images document the growth of the Hobet mine in Boone County, West Virginia, as it expands from ridge to ridge between 1984 to 2009. Iraq In the years following the Second Gulf War, Iraqi residents began reclaiming the country s nearly decimated Mesopotamian marshes. This series of images documents the transformation of the fabled landscape between 2000 and 2009. Yellow River Delta Once free to wander up and down the coast of the North China Plain, the Yellow River Delta has been shaped by levees, canals, and jetties in recent decades.

Watch this and other space videos at http://SpaceRip.com Best viewed in full screen 1080p. Using satellites, scientists have been tracking the movement of BP s Deep Water Horizon oil slick as currents have pushed it closer and closer to the Gulf Coast. Now, scientists at the National Center for Atmospheric Research have used supercomputers to simulate its path in coming months as it moves up the Atlantic seaboard in major ocean currents.