Tuesday, November 17, 2015

NASA Latest Images


The Witch Head Nebula
Image Credit & Copyright: Jeff Signorelli
Explanation: Double, double toil and trouble; Fire burn, and cauldron bubble .... maybe Macbeth should have consulted the Witch Head Nebula. A frighteningly shaped reflection nebula, this cosmic crone is about 800 light-years away though. Its malevolent visage seems to glare toward nearby bright star Rigel in Orion, just off the right edge of this frame. More formally known as IC 2118, the interstellar cloud of dust and gas is nearly 70 light-years across, its dust grains reflecting Rigel's starlight. In this composite portrait, the nebula's color is caused not only by the star's intense bluish light but because the dust grains scatter blue light more efficiently than red. The same physical process causes Earth's daytime sky to appear blue, although the scatterers in planet Earth's atmosphere are molecules of nitrogen and oxygen.


IC 1871: Inside the Soul Nebula
Image Credit & Copyright: Sara Wager
Explanation: This cosmic close-up looks deep inside the Soul Nebula. The dark and brooding dust clouds outlined by bright ridges of glowing gas are cataloged as IC 1871. About 25 light-years across, the telescopic field of view spans only a small part of the much larger Heart and Soul nebulae. At an estimated distance of 6,500 light-years the star-forming complex lies within the Perseus spiral arm of the Milky Way, seen in planet Earth's skies toward the constellation Cassiopeia. An example of triggered star formation, the dense star-forming clouds of IC 1871 are themselves sculpted by the intense winds and radiation of the region's massive young stars. This color image adopts a palette made popular in Hubble images of star-forming regions.


Massive Black Hole Shreds Passing Star
Illustration Video Credit: NASA's Goddard Space Flight Center, CI Lab
Explanation: What happens when a star gets too close to a black hole? Recent observations from Earth-orbiting observatories of an event dubbed ASASSN-14li, in a distant galactic center, appears to be giving one star's harrowing story. Although angularly unresolved, variations in high energy light indicate that some of the star became shredded and reformed into a disk swirling around the dark abyss. In the hypothesized scenario envisioned, a jet formed on the spin axis of the black hole. The innermost part of the disk, colored white, glows most strongly in X-rays and may drive a periodic wind, shown in blue. Future X-ray and ultraviolet observations of stellar disruptions by black holes -- including those in the center of our own galaxy -- hold promise of telling us about the complex dynamics of some of the hottest and highest-gravity places in the universe.


right from the Heart Nebula
Image Copyright: Simon Addis
Explanation: What's that inside the Heart Nebula? First, the large emission nebula dubbed IC 1805 looks, in whole, like a human heart. The nebula glows brightly in red light emitted by its most prominent element: hydrogen. The red glow and the larger shape are all created by a small group of stars near the nebula's center. In the center of the Heart Nebula are young stars from the open star cluster Melotte 15 that are eroding away several picturesque dust pillars with their energetic light and winds. The open cluster of stars contains a few bright stars nearly 50 times the mass of our Sun, many dim stars only a fraction of the mass of our Sun, and an absent microquasar that was expelled millions of years ago. The Heart Nebula is located about 7,500 light years away toward the constellation of Cassiopeia. At the top right is the companion Fishhead Nebula


Explanation: Two remarkable global maps of Jupiter's banded cloud tops can be compared by just sliding your cursor over this sharp projection (or follow this link) of image data from the Hubble Space Telescope. Both captured on January 19, during back-to-back 10 hour rotations of the ruling gas giant, the all-planet projections represent the first in a series of planned annual portraits by the Outer Planet Atmospheres Legacy program. Comparing the two highlights cloud movements and measures wind speeds in the planet's dynamic atmosphere. In fact, the Great Red Spot, the famous long-lived swirling storm boasting 300 mile per hour winds, is seen sporting a rotating, twisting filament. The images confirm that Great Red Spot is still shrinking, though still larger than planet Earth. Posing next to it (lower right) is Oval BA, also known as Red Spot Junior.


The Fractured North Pole of Saturn's Enceladus
Image Credit: NASA/JPL-Caltech/Space Science Institute
Explanation: The north pole of Saturn's moon Enceladus is unexpectedly fascinating and complex. Previous to the latest flyby of the robotic Cassini spacecraft, the northern region was known mostly for its unusually high abundance of craters. Last week's flyby, however, returned images of unprecedented detail, including the featured image showing the expected craters coupled with an unexpected and circuitous pattern of picturesque cracks and fractures. Broken terrain has been recorded at lower latitudes, with deep canyons dubbed Tiger Stripes near Enceladus' South Pole. The fractures may further indicate global interplay between the surface and potential seas underneath, seas that future missions might target for signs of life.


When Black Holes Collide
Video Credit & Copyright: Simulating Extreme Spacetimes Collaboration
Explanation: What happens when two black holes collide? This extreme scenario likely occurs in the centers of some merging galaxies and multiple star systems. The featured video shows a computer animation of the final stages of such a merger, while highlighting the gravitational lensing effects that would appear on a background starfield. The black regions indicate the event horizons of the dynamic duo, while a surrounding ring of shifting background stars indicates the position of their combined Einstein ring. All background stars not only have images visible outside of this Einstein ring, but also have one or more companion images visible on the inside. Eventually the two black holes coalesce. The end stages of such a merger may provide a strong and predictable blast of gravitational radiation, a much sought after form of radiation different than light that has never yet been directly observed. 


The Elephant's Trunk in IC 1396
Image Credit & Copyright: J.C. Canonne, P. Bernhard, D. Chaplain & L. Bourgon
Explanation: Like an illustration in a galactic Just So Story, the Elephant's Trunk Nebula winds through the emission nebula and young star cluster complex IC 1396, in the high and far off constellation of Cepheus. Of course, the cosmic elephant's trunk is over 20 light-years long. This composite was recorded through narrow band filters that transmit the light from ionized hydrogen, sulfur, and oxygen atoms in the region. The resulting image highlights the bright swept-back ridges that outline pockets of cool interstellar dust and gas. Such embedded, dark, tendril-shaped clouds contain the raw material for star formation and hide protostars within the obscuring cosmic dust. Nearly 3,000 light-years distant, the relatively faint IC 1396 complex covers a large region on the sky, spanning over 5 degrees.


In the Center of the Trifid Nebula
Image Credit: Subaru Telescope (NAOJ), Hubble Space Telescope, Martin Pugh; Processing: Robert Gendler
Explanation: Clouds of glowing gas mingle with dust lanes in the Trifid Nebula, a star forming region toward the constellation of the Archer (Sagittarius). In the center, the three prominent dust lanes that give the Trifid its name all come together. Mountains of opaque dust appear on the right, while other dark filaments of dust are visible threaded throughout the nebula. A single massive star visible near the center causes much of the Trifid's glow. The Trifid, also known as M20, is only about 300,000 years old, making it among the youngest emission nebulae known. The nebula lies about 9,000 light years away and the part pictured here spans about 10 light years. The above image is a composite with luminance taken from an image by the 8.2-m ground-based Subaru Telescope, detail provided by the 2.4-m orbiting Hubble Space Telescope, color data provided by Martin Pugh and image assembly and processing provided by Robert Gendler.

Source - NASA