A supernova is the explosion of a star. It is the largest explosion that takes place in space. Where Do Supernovas Take Place? Supernovas are often seen in other galaxies. But supernovas are difficult to see in our own Milky Way galaxy because dust blocks our view. In 1604, Johannes Kepler discovered the last observed supernova in the Milky Way. NASA’s Chandra telescope discovered the remains of a more recent supernova. It exploded in the Milky Way more than a hundred years ago. What Causes a Supernova? A supernova happens where there is a change in the core, or center, of a star. A change can occur in two different ways, with both resulting in a supernova. The first type of supernova happens in binary star systems. Binary stars are two stars that orbit the same point. One of the stars, a carbon-oxygen white dwarf, steals matter from its companion star. Eventually, the white dwarf accumulates too much matter. Having too much matter causes the star to explode, resulting in a supernova. The second type of supernova occurs at the end of a single star’s lifetime. As the star runs out of nuclear fuel, some of its mass flows into its core. Eventually, the core is so heavy that it cannot withstand its own gravitational force. The core collapses, which results in the giant explosion of a supernova. The sun is a single star, but it does not have enough mass to become a supernova.

Taking a closer look at solar activity across one year - month by month. January 2014 Bringing you the BEST Space and Astronomy videos online. Showcasing videos and images from the likes of NASA,ESA,Hubble etc.

Eruptive events on the sun can be wildly different. Some come just with a solar flare, some with an additional ejection of solar material called a coronal mass ejection (CME), and some with complex moving structures in association with changes in magnetic field lines that loop up into the sun's atmosphere, the corona. On July 19, 2012, an eruption occurred on the sun that produced all three. A moderately powerful solar flare exploded on the sun's lower right hand limb, sending out light and radiation. Next came a CME, which shot off to the right out into space. And then, the sun treated viewers to one of its dazzling magnetic displays -- a phenomenon known as coronal rain. Over the course of the next day, hot plasma in the corona cooled and condensed along strong magnetic fields in the region. Magnetic fields, themselves, are invisible, but the charged plasma is forced to move along the lines, showing up brightly in the extreme ultraviolet wavelength of 304 Angstroms, which highlights material at a temperature of about 50,000 Kelvin. This plasma acts as a tracer, helping scientists watch the dance of magnetic fields on the sun, outlining the fields as it slowly falls back to the solar surface. The footage in this video was collected by the Solar Dynamics Observatory's AIA instrument. SDO collected one frame every 12 seconds, and the movie plays at 30 frames per second, so each second in this video corresponds to 6 minutes of real time. The video covers 12:30 a.m. EDT to 10:00 p.m. EDT on July 19, 2012.

Meet Mitzi Adams, an astrophysicist studying the sun. Adams has been working as a solar scientist at NASA's Marshall Space Flight Center in Huntsville, Ala., since 1988. She analyzes data in an attempt to predict solar flares and coronal mass ejections, or CMEs. Knowing when a solar flare, or CME, is going to occur is important for our satellites in orbit, for astronauts in space, and even for power companies on the ground. Instruments on board satellites now improve these predictions. In this episode, Adams presents the latest information about the sun’s layers, coronal mass ejections, solar flares and solar cycles.

The Sun is the star at the center of the Solar System. It is a nearly perfect sphere of hot plasma, with internal convective motion that generates a magnetic field via a dynamo process. It is by far the most important source of energy for life on Earth. Its diameter is about 1.39 million kilometers (864,000 miles), or 109 times that of Earth, and its mass is about 330,000 times that of Earth. It accounts for about 99.86% of the total mass of the Solar System. Roughly three quarters of the Sun's mass consists of hydrogen (~73%); the rest is mostly helium (~25%), with much smaller quantities of heavier elements, including oxygen, carbon, neon, and iron. The Sun is a G-type main-sequence star (G2V) based on its spectral class. As such, it is informally and not completely accurately referred to as a yellow dwarf (its light is closer to white than yellow). It formed approximately 4.6 billion years ago from the gravitational collapse of matter within a region of a large molecular cloud. Most of this matter gathered in the center, whereas the rest flattened into an orbiting disk that became the Solar System. The central mass became so hot and dense that it eventually initiated nuclear fusion in its core. It is thought that almost all stars form by this process. The Sun currently fuses about 600 million tons of hydrogen into helium every second, converting 4 million tons of matter into energy every second as a result. This energy, which can take between 10,000 and 170,000 years to escape from its core, is the source of the Sun's light and heat. When hydrogen fusion in its core has diminished to the point at which the Sun is no longer in hydrostatic equilibrium, its core will undergo a marked increase in density and temperature while its outer layers expand, eventually transforming the Sun into a red giant. It is calculated that the Sun will become sufficiently large to engulf the current orbits of Mercury and Venus, and render Earth uninhabitable – but not for about five billion years. After this, it will shed its outer layers and become a dense type of cooling star known as a white dwarf, and no longer produce energy by fusion, but still glow and give off heat from its previous fusion. The enormous effect of the Sun on Earth has been recognized since prehistoric times, and the Sun has been regarded by some cultures as a deity. The synodic rotation of Earth and its orbit around the Sun are the basis of solar calendars, one of which is the predominant calendar in use today. Sunlight The solar constant is the amount of power that the Sun deposits per unit area that is directly exposed to sunlight. The solar constant is equal to approximately 1,368 W/m2 (watts per square meter) at a distance of one astronomical unit (AU) from the Sun (that is, on or near Earth). Sunlight on the surface of Earth is attenuated by Earth's atmosphere, so that less power arrives at the surface (closer to 1,000 W/m2) in clear conditions when the Sun is near the zenith. Sunlight at the top of Earth's atmosphere is composed (by total energy) of about 50% infrared light, 40% visible light, and 10% ultraviolet light. The atmosphere in particular filters out over 70% of solar ultraviolet, especially at the shorter wavelengths. Solar ultraviolet radiation ionizes Earth's dayside upper atmosphere, creating the electrically conducting ionosphere. The Sun's color is white, with a CIE color-space index near (0.3, 0.3), when viewed from space or when the Sun is high in the sky. When measuring all the photons emitted, the Sun is actually emitting more photons in the green portion of the spectrum than any other. When the Sun is low in the sky, atmospheric scattering renders the Sun yellow, red, orange, or magenta. Despite its typical whiteness, most people mentally picture the Sun as yellow; the reasons for this are the subject of debate. The Sun is a G2V star, with G2 indicating its surface temperature of approximately 5,778 K (5,505 °C, 9,941 °F), and V that it, like most stars, is a main-sequence star. The average luminance of the Sun is about 1.88 giga candela per square metre, but as viewed through Earth's atmosphere, this is lowered to about 1.44 Gcd/m2. However, the luminance is not constant across the disk of the Sun (limb darkening). The short answer is that it takes sunlight an average of 8 minutes and 20 seconds to travel from the Sun to the Earth.

The universe has long captivated us with its immense scales of distance and time. How far does it stretch? Where does it end, and what lies beyond its star fields and streams of galaxies extending as far as telescopes can see? These questions are beginning to yield to a series of extraordinary new lines of investigation and technologies that are letting us to peer into the most distant realms of the cosmos. But also at the behavior of matter and energy on the smallest of scales. Remarkably, our growing understanding of this kingdom of the ultra-tiny, inside the nuclei of atoms, permits us to glimpse the largest vistas of space and time. In ancient times, most observers saw the stars as a sphere surrounding the earth, often the home of deities. The Greeks were the first to see celestial events as phenomena, subject to human investigation rather than the fickle whims of the Gods. One sky-watcher, for example, suggested that meteors are made of materials found on Earth... and might have even come from the Earth. Those early astronomers built the foundations of modern science. But they would be shocked to see the discoveries made by their counterparts today. The stars and planets that once harbored the gods are now seen as infinitesimal parts of a vast scaffolding of matter and energy extending far out into space. Just how far began to emerge in the 1920s. Working at the huge new 100-inch Hooker Telescope on California's Mt. Wilson, astronomer Edwin Hubble, along with his assistant named Milt Humason, analyzed the light of fuzzy patches of sky... known then as nebulae. They showed that these were actually distant galaxies far beyond our own. Hubble and Humason discovered that most of them are moving away from us. The farther out they looked, the faster they were receding. This fact, now known as Hubble's law, suggests that there must have been a time when the matter in all these galaxies was together in one place. That time, when our universe sprung forth, has come to be called the Big Bang. How large the cosmos has gotten since then depends on how long its been growing and its expansion rate. Recent precision measurements gathered by the Hubble space telescope and other instruments have brought a consensus... That the universe dates back 13.7 billion years. Its radius, then, is the distance a beam of light would have traveled in that time ... 13.7 billion light years. That works out to about 1.3 quadrillion kilometers. In fact, it's even bigger.... Much bigger. How it got so large, so fast, was until recently a deep mystery. That the universe could expand had been predicted back in 1917 by Albert Einstein, except that Einstein himself didn't believe it until he saw Hubble and Humason's evidence. Einstein's general theory of relativity suggested that galaxies could be moving apart because space itself is expanding. So when a photon gets blasted out from a distant star, it moves through a cosmic landscape that is getting larger and larger, increasing the distance it must travel to reach us. In 1995, the orbiting telescope named for Edwin Hubble began to take the measure of the universe... by looking for the most distant galaxies it could see. Taking the expansion of the universe into account, the space telescope found galaxies that are now almost 46 billion light years away from us in each direction... and almost 92 billion light years from each other. And that would be the whole universe... according to a straightforward model of the big bang. But remarkably, that might be a mere speck within the universe as a whole, according to a dramatic new theory that describes the origins of the cosmos.

Voyager 1 and 2 update, female documentary narrator. Updates the Voyagers instrument status, Communication status, How we know Voyager 1 is in Interstellar Space, Where the Voyagers are headed now.