Schlagwort: NASA

Earlier this month, the Sun exhibited one of the longer filaments on record. Visible as the bright curving streak around the image center, the snaking filament’s full extent was estimated to be over half of the Sun’s radius — more than 350,000 kilometers long. A filament is composed of hot gas held aloft by the Sun’s magnetic field, so that viewed from the side it would appear as a raised prominence. A different, smaller prominence is simultaneously visible at the Sun’s edge. The featured image is in false-color and color-inverted to highlight not only the filament but the Sun’s carpet chromosphere. The bright dot on the upper right is actually a dark sunspot about the size of the Earth. Solar filaments typically last from hours to days, eventually collapsing to return hot plasma back to the Sun. Sometimes, though, they explode and expel particles into the Solar System, some of which trigger auroras on Earth. The pictured filament appeared in early September and continued to hold steady for about a week. via NASA https://ift.tt/W5SRfpJ

On Sept. 12, 1962, President Kennedy speaks before a crowd of 35,000 people at Rice University in Houston. via NASA https://ift.tt/W21NegQ

What are those red filaments in the sky? They are a rarely seen form of lightning confirmed only about 35 years ago: red sprites. Research has shown that following a powerful positive cloud-to-ground lightning strike, red sprites may start as 100-meter balls of ionized air that shoot down from about 80-km high at 10 percent the speed of light. They are quickly followed by a group of upward streaking ionized balls. The featured image was taken late last month from the Jeseniky Mountains in northern Moravia in the Czech Republic. The distance to the red sprites is about 200 kilometers. Red sprites take only a fraction of a second to occur and are best seen when powerful thunderstorms are visible from the side. via NASA https://ift.tt/0xqotvJ

How does your favorite planet spin? Does it spin rapidly around a nearly vertical axis, or horizontally, or backwards? The featured video animates NASA images of all eight planets in our Solar System to show them spinning side-by-side for an easy comparison. In the time-lapse video, a day on Earth — one Earth rotation — takes just a few seconds. Jupiter rotates the fastest, while Venus spins not only the slowest (can you see it?), but backwards. The inner rocky planets, across the top, most certainly underwent dramatic spin-altering collisions during the early days of the Solar System. The reasons why planets spin and tilt as they do remains a topic of research with much insight gained from modern computer modeling and the recent discovery and analysis of hundreds of exoplanets: planets orbiting other stars. via NASA https://ift.tt/0GwCYjf

This 180 degree panoramic night skyscape captures our Milky Way Galaxy as it arcs above the horizon on a winter’s night in August. Near midnight, the galactic center is close to the zenith with the clear waters of Lake Traful, Neuquen, Argentina, South America, planet Earth below. Zodiacal light, dust reflected sunlight along the Solar System’s ecliptic plane, is also visible in the region’s very dark night sky. The faint band of light reaches up from the distant snowy peaks toward the galaxy’s center. Follow the arc of the Milky Way to the left to find the southern hemisphere stellar beacons Alpha and Beta Centauri. Close to the horizon bright star Vega is reflected in the calm mountain lake. via NASA https://ift.tt/FavQZjs

This nighttime photograph from the International Space Station (ISS) as it orbited 261 miles above looks across the Mediterranean Sea from north Africa to southern Europe. via NASA https://ift.tt/Ml2KYWi