Demo Reel
A nova is a sudden, short-lived explosion from a compact star not much larger than Earth. The outburst comes from a collapsed star known as a white dwarf, which circles so close to a normal star that a stream of gas flows between them. This gas piles up into a layer on the white dwarf's surface until it reaches a flash point and detonates in a runaway thermonuclear explosion. Astronomers estimate that between 20 and 50 novae occur each year in our galaxy, but despite their power most go undiscovered. NASA's Fermi Gamma-ray Space Telescope has observed several nearby novae and found that each blast produces gamma rays, the most energetic form of light. Scientists think the gamma rays result from collisions among multiple shock waves that race from the site of the explosion in a rapidly expanding shell of debris. Watch the video to see an animation of a nova eruption. Cosmic Blast
This movie takes us on a space weather journey from the center of the sun to solar eruptions in the sun's atmosphere all the way to the effects of that activity near Earth. The view starts in the core of the sun where atoms fuse together to create light and energy. Next we travel toward the sun's surface, watching loops of magnetic fields rise up to break through the sun's atmosphere, the corona. In the corona is where we witness giant bursts of radiation and energy known as solar flares, as well as gigantic eruptions of solar material called coronal mass ejections or CMEs. The movie follows one of these CME's toward Earth where it impacts and compresses Earth's own protective magnetic bubble, the magnetosphere. As energy and particles from the sun funnel along magnetic field lines near Earth, they ultimately produce aurora at Earth's poles. Space Weather
NASA's Fermi Gamma-ray Space Telescope has detected gamma-rays from a nova for the first time. The finding stunned observers and theorists alike because it overturns a long-standing notion that 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. Fermi Sees a Nova
Billions of years ago when the Red Planet was young, it appears to have had a thick atmosphere that was warm enough to support oceans of liquid water - a critical ingredient for life. The animation shows how the surface of Mars might have appeared during this ancient clement period, beginning with a flyover of a Martian lake. The artist's concept is based on evidence that Mars was once very different. Rapidly moving clouds suggest the passage of time, and the shift from a warm and wet to a cold and dry climate is shown as the animation progresses. The lakes dry up, while the atmosphere gradually transitions from Earthlike blue skies to the dusty pink and tan hues seen on Mars today. Mars Transition
When you navigate with a compass you can orient yourself thanks to Earth's global magnetic field. But on Mars, if you were to walk around with a compass it would haphazardly point from one anomaly to another, because the Red Planet does not possess a global magnetosphere. Scientists think that this lack of a protective magnetic field may have allowed the solar wind to strip away the Martian atmosphere over billions of years, and now NASA's MAVEN spacecraft will study this process in detail with its pair of ring core fluxgate magnetometers. MAVEN Magnetometer