Cosmos Without Gravitation. One-Minute Astronomer - Star Gazing and Basic Astronomy. Astrology. Titan. Saturn's Moon Phoebe - Solar System Reference Library. Saturn’s moon Phoebe — Phoebe is the outermost of Saturn’s known moons. Phoebe is almost 4 times more distant from Saturn than its nearest neighbor (Iapetus). It was discovered by William Henry Pickering in 1898. Most of Saturn’s moons have very bright surfaces, but Phoebe’s albedo is very low (.06), as dark as lampblack. All of Saturn’s moons except for Phoebe and Iapetus orbit very nearly in the plane of Saturn’s equator. Phoebe’s orbit is retrograde, inclined almost 175, and is highly eccentric. The plane of its orbit is much closer to the solar system’s ecliptic than it is to Saturn’s. Phoebe is also unusual in that it does not rotate synchronously as all the other moons of Saturn except Hyperion do.
All this suggests that it may be a captured asteroid with a composition unmodified since the time it was formed in the outer Solar System. Since they are so small they never heated up sufficiently to change chemical composition. Discovery Orbital characteristics Physical characteristics. Strongest evidence yet indicates Enceladus hiding saltwater ocean. This image shows icy spray spewing from Saturn's moon, Enceladus. Credit: NASA/JPL/Space Science Institute The new discovery was made during the Cassini-Huygens mission to Saturn , a collaboration of NASA, the European Space Agency and the Italian Space Agency. Launched in 1997, the mission spacecraft arrived at the Saturn system in 2004 and has been touring the giant ringed planet and its vast moon system ever since.
The plumes shooting water vapor and tiny grains of ice into space were originally discovered emanating from Enceladus -- one of 19 known moons of Saturn -- by the Cassini spacecraft in 2005. The plumes were originating from the so-called "tiger stripe" surface fractures at the moon's south pole and apparently have created the material for the faint E Ring that traces the orbit of Enceladus around Saturn. During three of Cassini's passes through the plume in 2008 and 2009, the Cosmic Dust Analyser, or CDA, on board measured the composition of freshly ejected plume grains. Giant Ribbon Discovered at the Edge of the Solar System.
+ Play Audio | + Download Audio | + Join mailing list October 15, 2009: For years, researchers have known that the solar system is surrounded by a vast bubble of magnetism. Called the "heliosphere," it springs from the sun and extends far beyond the orbit of Pluto, providing a first line of defense against cosmic rays and interstellar clouds that try to enter our local space.
Although the heliosphere is huge and literally fills the sky, it emits no light and no one has actually seen it. Until now. NASA's IBEX (Interstellar Boundary Explorer) spacecraft has made the first all-sky maps of the heliosphere and the results have taken researchers by surprise. The maps are bisected by a bright, winding ribbon of unknown origin: Above: IBEX's all-sky map of energetic neutral atom emission reveals a bright filament of unknown origin.
"This is a shocking new result," says IBEX principal investigator Dave McComas of the Southwest Research Institute. "That cannot be a coincidence," says McComas. Saturn's Shockwaves Reach Supernova Force. Scientists are particularly interested in "quasi-parallel" shocks, where the magnetic field and the "forward"-facing direction of the shock are almost aligned, as may be found in supernova remnants. The new study, led by Masters describes the first detection of significant acceleration of electrons in a quasi-parallel shock at Saturn, coinciding with what may be the strongest shock ever encountered at the ringed planet. Shock waves are commonplace in the universe, for example in the aftermath of a stellar explosion as debris accelerate outward in a supernova remnant, or when the flow of particles from the sun - the solar wind - impinges on the magnetic field of a planet to form a bow shock.
Under certain magnetic field orientations and depending on the strength of the shock, particles can be accelerated to close to the speed of light at these boundaries. These may be the dominant source of cosmic rays, high-energy particles that pervade our galaxy. The Daily Galaxy via NASA. Orbiting Earth 101: What You’d See / What You’d Do. “I saw for the first time the earth’s shape. I could easily see the shores of continents, islands, great rivers, folds of the terrain, large bodies of water. The horizon is dark blue, smoothly turning to black. . . the feelings which filled me I can express with one word–joy.”
-Yuri Gagarin It takes a tremendous amount of energy to do any type of heavy lifting, and the most extreme example of this is lifting something all the way up off of the Earth, out of the atmosphere, and into space! And once you’re up there, at least 300 km above the Earth’s surface, the sights you’ve got are bound to be absolutely amazing! For example, if you took the US Space Shuttle up, you’d likely dock with the International Space Station, and get to see something as breathtaking as this: But gravity is a funny thing. Image credit: Boeing. Any guesses as to what that speed is at the altitude of the International Space Station? But let’s take a look at the Earth itself. Astronomy & Space. Kepler’s Tally of Planets - Interactive Feature.
NASA Science. Physics 7: Relativity and Cosmology. Galaxy Zoo. Build a Universe with the CMB Power Spectrum Analyzer. Using the faint temperature patterns formed in the sky by cosmic microwaves, scientific analysis can measure things like the age, shape, and composition of the early universe. Looking out at the universe, back in time, we see evolution of matter from hot plasma, to very simple clouds of hydrogen gas, to complex galaxies and planets.
The universe can have strange properties, but simple structures like plasma and hydrogen gas behave in predictable ways- for which we can create accurate computer models of behavior. The WMAP Cosmic Microwave Background (CMB) Analyzer shows how the energy signature (called the Angular Power Spectrum) varies as some of the more important input parameters of our universe are modified. The blue line is the CMB power spectrum for "your" universe. Try changing amounts of each ingredient and property. See if you can get the blue line to match the red line, which is based on the measurements from the WMAP mission. The Graph The Universe Content: the Ingredients. Secret Worlds: The Universe Within - Interactive Java Tutorial.
Secret Worlds: The Universe Within View the Milky Way at 10 million light years from the Earth. Then move through space towards the Earth in successive orders of magnitude until you reach a tall oak tree just outside the buildings of the National High Magnetic Field Laboratory in Tallahassee, Florida. After that, begin to move from the actual size of a leaf into a microscopic world that reveals leaf cell walls, the cell nucleus, chromatin, DNA and finally, into the subatomic universe of electrons and protons. Once the tutorial has completely downloaded, a set of the arrows will appear that allow the user to increase or decrease the view magnitude in Manual mode. Click on the Auto button to return to the Automatic mode. Notice how each picture is actually an image of something that is 10 times bigger or smaller than the one preceding or following it.
The number that appears on the lower right just below each image is the size of the object in the picture. Contributing Authors David A. Daily Galaxy. Eyes on the Solar System. The Asteroid That Is Coming Really Close To Earth. In February, Asteroid 2012 DA 14 will come so close to earth that it will be nearer to our planet than many satellites are. This asteroid, which really should get a new name, is about half the size of a football field. Its orbit is similar to that of the Earth itself, in size and shape, but at an angle to the Earth’s plane, so it’s like the asteroid and the earth are driving in circles on two oval tracks that intersect at two points but there is no red light.
Asteroid 2012 DA 14 was discovered with gear provided to an observatory with a grant from the Planetary Society. Which makes me want to join the Planetary Society. This asteroid is not going to hit the earth now or during any of the next few decades, but eventually it may well do so. We need to keep an eye on it. The closest approach will be on Feb 15th, when it will be a mere 27,330 kilometers from the surface of the earth.