Friday, August 7, 2015

NASA Latest Images



Full Moon, Full Earth
Image Credit: NASA, NOAA/DSCOVR
Explanation: The Moon was new on July 16. Its familiar nearside facing the surface of planet Earth was in shadow. But on that date a million miles away, the Deep Space Climate Observatory (DSCOVR) spacecraft's Earth Polychromatic Imaging Camera (EPIC) captured this view of an apparently Full Moon crossing in front of a Full Earth. In fact, seen from the spacecraft's position beyond the Moon's orbit and between Earth and Sun, the fully illuminated lunar hemisphere is the less familiar farside. Only known since the dawn of the space age, the farside is mostly devoid of dark lunar maria that sprawl across the Moon's perpetual Earth-facing hemisphere. Only the small dark spot of the farside's Mare Moscoviense (Sea of Moscow) is clear, at the upper left. Planet Earth's north pole is near 11 o'clock, with the North America visited by Hurricane Dolores near center. Slight color shifts are visible around the lunar edge, an artifact of the Moon's motion through the field caused by combining the camera's separate exposures taken in quick succession through different color filters. While monitoring the Earth and solar wind for space weather forcasts, about twice a year DSCOVR can capture similar images of Moon and Earth together as it crosses the orbital plane of the Moon.


Stripping ESO 137-001
NASA, ESA, CXC
Explanation: Spiral galaxy ESO 137-001 hurtles through massive galaxy cluster Abell 3627 some 220 million light years away. The distant galaxy is seen in this colorful Hubble/Chandra composite image through a foreground of the Milky Way's stars toward the southern constellation Triangulum Australe. As the spiral speeds along at nearly 7 million kilometers per hour, its gas and dust are stripped away when ram pressure with the cluster's own hot, tenuous intracluster medium overcomes the galaxy's gravity. Evident in Hubble's near visible light data, bright star clusters have formed in the stripped material along the short, trailing blue streaks. Chandra's X-ray data shows off the enormous extent of the heated, stripped gas as diffuse, darker blue trails stretching over 400,000 light-years toward the bottom right. The significant loss of dust and gas will make new star formation difficult for this galaxy. A yellowish elliptical galaxy, lacking in star forming dust and gas, is just to the right of ESO 137-001 in the frame.


The ISS and a Colorful Moon
Image Credit & Copyright: Dylan O'Donnell
Explanation: Tonight's Full Moon, the second Full Moon in July, could be called a blue moon according to modern folklore. But this sharp and detailed mosaic, recorded with telescope and digital camera just before July's first Full Moon, actually does show a colorful lunar surface. The colors have been enhanced in the processed image but are real nonetheless, corresponding to real differences in the chemical makeup of the lunar surface. Also easy to see especially when the Moon is near full phase, bright rays from 85 kilometer wide Tycho crater at the upper right extend far across the lunar surface. Against the southern lunar highlands above and right of Tycho is an amazingly detailed silhouette of the International Space Station. Seen from Byron Bay, NSW Australia on June 30, the ISS lunar transit lasted about 1/3 of a second, captured with a fast shutter speed in burst mode.


Milky Way over Uluru
Image Credit & Copyright: Babak Tafreshi (TWAN)
Explanation: The central regions of our Milky Way Galaxy rise above Uluru/Ayers Rock in this striking night skyscape. Recorded on July 13, a faint airglow along the horizon shows off central Australia's most recognizable landform in silhouette. Of course the Milky Way's own cosmic dust clouds appear in silhouette too, dark rifts along the galaxy's faint congeries of stars. Above the central bulge, rivers of cosmic dust converge on a bright yellowish supergiant star Antares. Left of Antares, wandering Saturn shines in the night.


Milky Way and Aurora over Antarctica
Image Credit & Copyright: LI Hang
Explanation: It has been one of the better skies of this long night. In parts of Antarctica, not only is it winter, but the Sun can spend weeks below the horizon. At China's Zhongshan Station, people sometimes venture out into the cold to photograph a spectacular night sky. The featured image from one such outing was taken in mid-July, just before the end of this polar night. Pointing up, the wide angle lens captured not only the ground at the bottom, but at the top as well. In the foreground is a colleague also taking pictures. In the distance, a spherical satellite receiver and several windmills are visible. Numerous stars dot the night sky, including Sirius and Canopus. Far in the background, stretching overhead from horizon to horizon, is the central band of our Milky Way Galaxy. Even further in the distance, visible as extended smudges near the top, are the Large and Small Magellanic Clouds, satellite galaxies near our huge Milky Way Galaxy.


Rainbows and Rays over Bryce Canyon
Image Credit & Copyright: John Rummel
Explanation: What's happening over Bryce Canyon? Two different optical effects that were captured in one image taken earlier this month. Both effects needed to have the Sun situated directly behind the photographer. The nearest apparition was the common rainbow, created by sunlight streaming from the setting sun over the head of the photographer, and scattering from raindrops in front of the canyon. If you look closely, even a second rainbow appears above the first. More rare, and perhaps more striking, are the rays of light that emanate out from the horizon above the canyon. These are known as anticrepuscular rays and result from sunlight streaming though breaks in the clouds, around the sky, and converging at the point 180 degrees around from the Sun. Geometrically, this antisolar point must coincide with the exact center of the rainbows. Located in Utah, USA, Bryce Canyon itself contains a picturesque array of ancient sedimentary rock spires known as hoodoos.


The Deep Lagoon
Image Credit & Copyright: Adam Block, Mt. Lemmon SkyCenter, Univ. Arizona
Explanation: Ridges of glowing interstellar gas and dark dust clouds inhabit the turbulent, cosmic depths of the Lagoon Nebula. Also known as M8, The bright star forming region is about 5,000 light-years distant. But it still makes for a popular stop on telescopic tours of the constellation Sagittarius, toward the center of our Milky Way Galaxy. Dominated by the telltale red emission of ionized hydrogen atoms recombining with stripped electrons, this stunning, deep view of the Lagoon's central reaches is about 40 light-years across. Near the center of the frame, the bright hourglass shape is gas ionized and sculpted by energetic radiation and extreme stellar winds from a massive young star.


Apollo 17 at Shorty Crater
Image Credit: Apollo 17 Crew, NASA
Explanation: On the Moon, it is easy to remember where you parked. In December of 1972, Apollo 17 astronauts Eugene Cernan and Harrison Schmitt spent about 75 hours on the Moon in the Taurus-Littrow valley, while colleague Ronald Evans orbited overhead. This sharp image was taken by Cernan as he and Schmitt roamed the valley floor. The image shows Schmitt on the left with the lunar rover at the edge of Shorty Crater, 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. Now forty three years later, Cernan and Schmitt are still the last to walk on the Moon.


A Proton Arc Over Lake Superior
Image Credit & Copyright: Ken Williams
Explanation: The setting had been picked out -- all that was needed was an aurora. And late last August, forecasts predicted that an otherwise beautiful night sky would be lit up with auroral green. Jumping into his truck, the astrophotographer approached his secret site -- but only after a five hour drive across the rural Upper Peninsula of Michigan. What he didn't know was that his luck was just beginning. While setting up for the image, a proton arc -- a rare type of aurora -- appeared. The red arc lasted only about 15 minutes, but that was long enough to capture in a 30-second exposure. As the name indicates, proton arcs are caused not by electrons but by more massive protons that bombard the Earth's atmosphere following an energetic event on the Sun. In the featured image, the yellow lights on the horizon are the city lights of Marquette, Michigan, USA. The blue and yellow rocks in the Lake Superior foreground are lit by a LED flashlight. Also captured, to the left of the red proton arc, was the band of our Milky Way Galaxy.


Virgo Cluster Galaxies
Image Credit & Copyright: Rogelio Bernal Andreo
Explanation: Well over a thousand galaxies are known members of the Virgo Cluster, the closest large cluster of galaxies to our own local group. In fact, the galaxy cluster is difficult to appreciate all at once because it covers such a large area on the sky. This careful wide-field mosaic of telescopic images clearly records the central region of the Virgo Cluster through faint foreground dust clouds lingering above the plane of our own Milky Way galaxy. The cluster's dominant giant elliptical galaxy M87, is just below and to the left of the frame center. To the right of M87 is a string of galaxies known as Markarian's Chain. A closer examination of the image will reveal many Virgo cluster member galaxies as small fuzzy patches. Sliding your cursor over the image will label the larger galaxies using NGC catalog designations. Galaxies are also shown with Messier catalog numbers, including M84, M86, and prominent colorful spirals M88, M90, and M91. On average, Virgo Cluster galaxies are measured to be about 48 million light-years away. The Virgo Cluster distance has been used to give an important determination of the Hubble Constant and the scale of the Universe.


X-ray Echoes from Circinus X-1
Image Credit: X-ray - NASA/CXC/Univ. Wisconsin-Madison/S.Heinz et al, Optical - DSS
Explanation: Circinus X-1 is an X-ray binary star known for its erratic variability. In the bizarre Circinus X-1 system, a dense neutron star, the collapsed remnant of a supernova explosion, orbits with a more ordinary stellar companion. Observations of the X-ray binary in months following an intense X-ray flare from the source in 2013 progressively revealed striking concentric rings - bright X-ray light echoes from four intervening clouds of interstellar dust. In this X-ray/optical composite, the swaths of Chandra Observatory X-ray image data showing partial outlines of the rings are in false colors. Remarkably, timing the X-ray echoes, along with known distances to the interstellar dust clouds, determines the formerly highly uncertain distance to Circinus X-1 itself to be 30,700 light-years.

Stereo Pluto
Image Credit: NASA, Johns Hopkins University/APL,
Southwest Research Institute - Stereo Assembly: Brian May
Explanation: These two detailed, true color images of Pluto were captured during the historic New Horizons flyby last month. With slightly different perspectives on the now recognizeable surface features they are presented in this first high quality stereo pair intended for viewing by denizens of planet Earth. The left hand image (left eye) is a mosaic recorded when the spacecraft was about 450,000 kilometers from Pluto. The right single image was acquired earlier, a last full look before the spacecraft's closest approach. Despite a difference in resolution, the pair combine for a stunning 3D perception of the distant, underworldly terrain.

Source - NASA