Many wonders are visible when flying over the Earth at night. Such visual spectacles occur every day for astronauts in low Earth orbit, but the featured video captured several from the International Space Station (ISS) in 2011 and set them to rousing music. Passing below are white clouds, orange city lights, lightning flashes in thunderstorms, and dark blue seas. On the horizon is the golden haze of Earth's thin atmosphere, frequently decorated by dancing auroras as the video progresses. The green parts of auroras typically remain below the space station, but the station flies right through the red and purple auroral peaks. Solar panels of the ISS are seen around the frame edges. The ominous wave of approaching brightness at the end of each sequence is just the dawn of the sunlit half of Earth, a dawn that occurs every 90 minutes. via NASA https://ift.tt/WqVoCuJ

It is still not known why the Sun's light is missing some colors. Here are all the visible colors of the Sun, produced by passing the Sun's light through a prism-like device. The spectrum was created at the McMath-PierceSolar Observatory and shows, first off, that although our white-appearing Sun emits light of nearly every color, it appears brightest in yellow-green light. The dark patches in the featured spectrum arise from gas at or above the Sun's surface absorbing sunlight emitted below. Since different types of gas absorb different colors of light, it is possible to determine what gasses compose the Sun. Helium, for example, was first discovered in 1868 on a solar spectrum and only later found here on Earth. Today, the majority of spectral absorption lines have been identified - but not all. via NASA https://ift.tt/6hXb9IC

Apollo 17 at Shorty Crater

Fifty three years ago, in December of 1972, Apollo 17 astronauts Eugene Cernan and Harrison Schmitt spent about 75 hours on the Moon exploring the Taurus-Littrow valley, while colleague Ronald Evans orbited overhead. This snapshot from another world was taken by Cernan as he and Schmitt roamed the lunar valley's floor. The image shows Schmitt next to the lunar rover parked at the southeast rim of Shorty Crater. That location is near the spot where geologist Schmitt discovered orange lunar soil. The Apollo 17 crew returned with 110 kilograms of rock and soil samples, more than was returned from any of the other lunar landing sites. And for now, Cernan and Schmitt are the last to walk on the Moon. via NASA https://ift.tt/RHqa3xm

The Bipolar Jets of KX Andromedae

Blasting outward from variable star KX Andromedae, these stunning bipolar jets are 19 light-years long. Recently discovered, they are revealed in unprecedented detail in this deep telescopic image centered on KX And and composed from over 692 hours of combined image data. In fact, KX And is spectroscopically found to be an interacting binary star system consisting of a bright, hot B-type star with a swollen cool giant star as its co-orbiting, close companion. The stellar material from the cool giant star is likely being transferred to the hot B-type star through an accretion disk, with spectacular symmetric jets driven outward perpendicular to the disk itself. The known distance to KX And of 2,500 light-years, angular size of the jets, and estimated inclination of the accretion disk lead to the size estimate for each jet of an astonishing 19 light-years. via NASA https://ift.tt/2JRwncT

Galaxies in the Furnace

An example of violence on a cosmic scale, enormous elliptical galaxy NGC 1316 lies about 75 million light-years away toward Fornax, the southern constellation of the Furnace. Investigating the startling sight, astronomers suspect the giant galaxy of colliding with smaller neighbor NGC 1317 seen just right of the large galaxy's center, producing far flung star streams in loops and shells. Light from their close encounter would have reached Earth some 100 million years ago. In the sharp telescopic image, the central regions of NGC 1316 and NGC 1317 appear separated by over 100,000 light-years. Complex dust lanes visible within also indicate that NGC 1316 is itself the result of a merger of galaxies in the distant past. Found on the outskirts of the Fornax galaxy cluster, NGC 1316 is known as Fornax A. One of the visually brightest of the Fornax cluster galaxies it is one of the strongest and largest celestial radio sources with radio emission extending well beyond this one degree wide field-of-view. via NASA https://ift.tt/WlqD267

What would it look like to plunge into a monster black hole? This image from a supercomputer visualization shows the entire sky as seen from a simulated camera plunging toward a 4-million-solar-mass black hole, similar to the one at the center of our galaxy. The camera lies about 16 million kilometers from the black hole’s event horizon and is moving inward at 62% the speed of light. Thanks to gravity’s funhouse effects, the starry band of the Milky Way appears both as a compact loop at the top of this view and as a secondary image stretching across the bottom. Move the cursor over the image for additional explanations. Visualizations like this allow astronomers to explore black holes in ways not otherwise possible. via NASA https://ift.tt/fT6vdCD

What's happening in the center of nearby spiral galaxy M77? The face-on galaxy lies a mere 47 million light-years away toward the constellation of the Sea Monster (Cetus). At that estimated distance, this gorgeous island universe is about 100 thousand light-years across. Also known as NGC 1068, its compact and very bright core is well studied by astronomers exploring the mysteries of supermassive black holes in active Seyfert galaxies. M77's active core glows bright at x-ray, ultraviolet, visible, infrared, and radio wavelengths. The featured sharp image of M77 was taken by the Hubble Space Telescope. The image shows details of the spiral's winding spiral arms as traced by obscuring red dust clouds and blue star clusters, all circling the galaxy's bright white luminous center. via NASA https://ift.tt/QtRWhEu