NGC 6888: The Crescent Nebula NGC 6888: The Crescent Nebula

NGC 6888, also known as the Crescent Nebula, is a cosmic bubble about 25 light-years across, blown by winds from its central, bright, massive star. This sharp telescopic portrait uses narrow band image data that isolates light from hydrogen and oxygen atoms in the wind-blown nebula. The oxygen atoms produce the blue-green hue that seems to enshroud the detailed folds and filaments. Visible within the nebula, NGC 6888's central star is classified as a Wolf-Rayet star (WR 136). The star is shedding its outer envelope in a strong stellar wind, ejecting the equivalent of the Sun's mass every 10,000 years. The nebula's complex structures are likely the result of this strong wind interacting with material ejected in an earlier phase. Burning fuel at a prodigious rate and near the end of its stellar life this star should ultimately go out with a bang in a spectacular supernova explosion. Found in the nebula rich constellation Cygnus, NGC 6888 is about 5,000 light-years away. via NASA http://ift.tt/1tgw3hK

Pluto at Night Pluto at Night

The night side of Pluto spans this shadowy scene. The spacebased view with the Sun behind the distant world was captured by New Horizons last July. The spacecraft was at a range of over 21,000 kilometers, about 19 minutes after its closest approach. A denizen of the Kuiper Belt in dramatic silhouette, the image also reveals Pluto's tenuous, surprisingly complex layers of hazy atmosphere. The crescent twilight landscape near the top of the frame includes southern areas of nitrogen ice plains informally known as Sputnik Planum and rugged mountains of water-ice in the Norgay Montes. via NASA http://ift.tt/1OeuUkE

The Horsehead Nebula in Infrared from Hubble The Horsehead Nebula in Infrared from Hubble

While drifting through the cosmos, a magnificent interstellar dust cloud became sculpted by stellar winds and radiation to assume a recognizable shape. Fittingly named the Horsehead Nebula, it is embedded in the vast and complex Orion Nebula (M42). A potentially rewarding but difficult object to view personally with a small telescope, the above gorgeously detailed image was taken in 2013 in infrared light by the orbiting Hubble Space Telescope in honor of the 23rd anniversary of Hubble's launch. The dark molecular cloud, roughly 1,500 light years distant, is cataloged as Barnard 33 and is seen above primarily because it is backlit by the nearby massive star Sigma Orionis. The Horsehead Nebula will slowly shift its apparent shape over the next few million years and will eventually be destroyed by the high energy starlight. via NASA http://ift.tt/1WEJ1T7

Night on Venus in Infrared from Orbiting Akatsuki Night on Venus in Infrared from Orbiting Akatsuki

Why is Venus so different from Earth? To help find out, Japan launched the robotic Akatsuki spacecraft which entered orbit around Venus late last year after an unplanned five-year adventure around the inner Solar System. Even though Akatsuki has passed its original planned lifetime, the spacecraft and its instruments are operating so well that much of its original mission has been reinstated. In the featured image taken by Akatsuki late last month, Venus was captured in infrared light showing a surprising amount of atmospheric structure on its night side. The vertical orange terminator stripe between night and day is so wide because of light is so diffused by Venus' thick atmosphere. Also known as the Venus Climate Orbiter, Akatsuki has cameras and instruments that will investigate unknowns about the planet, including whether volcanoes are still active, whether lightning occurs in the dense atmosphere, and why wind speeds greatly exceed the planet's rotation speed. via NASA http://ift.tt/1WD9PDc

The Supernova and Cepheids of Spiral Galaxy UGC 9391 The Supernova and Cepheids of Spiral Galaxy UGC 9391

What can this galaxy tell us about the expansion rate of the universe? Perhaps a lot because UGC 9391, featured, not only contains Cepheid variable stars (red circles) but also a recent Type Ia supernova (blue X). Both types of objects have standard brightnesses, with Cepheids typically being seen relatively nearby, while supernovas are seen much farther away. Therefore, this spiral is important because it allows a calibration between the near and distant parts of our universe. Unexpectedly, a recent analysis of new Hubble data from UGC 9391 and several similar galaxies has bolstered previous indications that Cepheids and supernovas are expanding with the universe slightly faster than expected from expansion measurements of the early universe. Given the multiple successes of early universe concordance cosmology, astrophysicists are now vigorously speculating about possible reasons for this discrepancy. Candidate explanations range from the sensational, such as the inclusion of unusual cosmological components types such as phantom energy and dark radiation, to the mundane, including statistical flukes and underestimated sources of systematic errors. Numerous future observations are being planned to help resolve the conundrum. via NASA http://ift.tt/1UtA090

Comet PanSTARRS and the Helix Nebula Comet PanSTARRS and the Helix Nebula

It's rare that such different objects are imaged so close together. Such an occasion is occurring now, though, and was captured two days ago in combined parallel exposures from the Canary Islands of Spain. On the lower right, surrounded by a green coma and emanating an unusually split blue ion tail diagonally across the frame, is Comet C/2013 X1 (PanSTARRS). This giant snowball has been falling toward our Sun and brightening since its discovery in 2013. Although Comet PannSTARRS is a picturesque target for long-duration exposures of astrophotography, it is expected to be only barely visible to the unaided eye when it reaches its peak brightness in the next month. On the upper left, surrounded by red-glowing gas, is the also-picturesque Helix Nebula. At 700 light years distant, the Helix is not only much further away than the comet, but is expected to retain its appearance for thousands of years. via NASA http://ift.tt/1XtZrOW

The Shadow of Surveyor 1 The Shadow of Surveyor 1

Fifty years ago, Surveyor 1 reached the Moon. Launched on May 30, 1966 and landed on June 2, 1966 with the Moon at full phase it became the first US spacecraft to make a soft landing on another world. The first of seven Surveyor missions intended to test the lunar terrain for the planned Apollo landings it sent back over 10,000 images before lunar nightfall on June 14. The total rose to over 11,000 images returned before its second lunar night began on July 13. Surveyor 1 continued to respond from the lunar surface until January 7, 1967. Captured in this 2009 image from the Lunar Reconnaissance Orbiter, the first Surveyor still stands at its landing site, a speck in the Oceanus Procellarum (the Ocean of Storms). With the Sun low on the western horizon the lonely, 3.3 meter tall spacecraft casts a shadow almost 15 meters long in the late lunar afternoon. via NASA http://ift.tt/1U4F5J7

NGC 4631: The Whale Galaxy NGC 4631: The Whale Galaxy

NGC 4631 is a big beautiful spiral galaxy. Seen edge-on, it lies only 25 million light-years away in the well-trained northern constellation Canes Venatici. The galaxy's slightly distorted wedge shape suggests to some a cosmic herring and to others its popular moniker, The Whale Galaxy. Either way, it is similar in size to our own Milky Way. In this sharp color image, the galaxy's yellowish core, dark dust clouds, bright blue star clusters, and red star forming regions are easy to spot. A companion galaxy, the small elliptical NGC 4627 is just above the Whale Galaxy. Faint star streams seen in deep images are the remnants of small companion galaxies disrupted by repeated encounters with the Whale in the distant past. The Whale Galaxy is also known to have spouted a halo of hot gas glowing in X-rays. via NASA http://ift.tt/1PqPBu1

Three Planets from Pic du Midi Three Planets from Pic du Midi

Seen any planets lately? All three planets now shining brightly in the night sky are imaged in these panels, captured last week with the 1 meter telescope at Pic du Midi Observatory in the French Pyrenees. Near opposition and closest to Earth on May 30, Mars is presently offering the best ground-based photo-ops in the last decade. The sharp image finds clouds above the Red Planet's north pole (top) and towering volcanos near its right limb. Saturn reaches its own opposition tonight, its bright rings and gaps clearly revealed in the telescopic portrait. Jupiter is currently highest during the evening twilight and shows off its planet-girdling cloud bands and Great Red Spot in this scene. Of course close-up images of the ruling gas giant will follow the July arrival of the solar-powered Juno spacecraft and JunoCam. via NASA http://ift.tt/1Xki47V

Stars and Gas of the Running Chicken Nebula Stars and Gas of the Running Chicken Nebula

To some, it looks like a giant chicken running across the sky. To others, it looks like a gaseous nebula where star formation takes place. Cataloged as IC 2944, the Running Chicken Nebula spans about 100 light years and lies about 6,000 light years away toward the constellation of the Centaur (Centaurus). The featured image, shown in scientifically assigned colors, was captured recently in an 11-hour exposure from a backyard near Melbourne, Australia. Two star clusters are visible: the Pearl Cluster seen on the far left, and Collinder 249 embedded in the nebula's glowing gas. Although difficult to discern here, several dark molecular clouds with distinct shapes can be found inside the nebula. via NASA http://ift.tt/1UapnIf