Pages

Mar 11, 2020

An Extreme Black Hole Outburst An Extreme Black Hole Outburst


Astronomers believe they have now found the most powerful example of a black hole outburst yet seen in our Universe. The composite, false-color featured image is of a cluster of galaxies in the constellation of Ophiuchus, the serpent-bearer. The composite includes X-ray images (from the Chandra X-ray Observatory and XMM-Newton) in purple, and a radio image (from India's Giant Metrewave Radio Telescope) in blue (along with an infrared image of the galaxies and stars in the field in white for good measure). The dashed line marks the border of a cavity blown out by the supermassive black hole which lurks at the center of the galaxy marked by the cross. Radio emission fills this cavity. This big blowout is believed to be due to the black hole eating too much and experiencing a transient bout of "black hole nausea", which resulted in the ejection of a powerful radio jet blasting into intergalactic space. The amount of energy needed to blow this cavity is equivalent to about 10 billion supernova explosions. via NASA https://ift.tt/39RSf8h

Mar 10, 2020

Wide Field: Fox Fur, Unicorn, and Christmas Tree Wide Field: Fox Fur, Unicorn, and Christmas Tree


What do the following things have in common: a cone, the fur of a fox, and a Christmas tree? Answer: they all occur in the constellation of the unicorn (Monoceros). Pictured as a star forming region and cataloged as NGC 2264, the complex jumble of cosmic gas and dust is about 2,700 light-years distant and mixes reddish emission nebulae excited by energetic light from newborn stars with dark interstellar dust clouds. Where the otherwise obscuring dust clouds lie close to the hot, young stars they also reflect starlight, forming blue reflection nebulae. The featured wide-field image spans over three times the diameter of a full moon, covering over 100 light-years at the distance of NGC 2264. Its cast of cosmic characters includes the Fox Fur Nebula, whose convoluted pelt lies just to the lower right of the image center, bright variable star S Mon visible just above the Fox Fur, and the Cone Nebula just to the left. Given their distribution, the stars of NGC 2264 are also known as the Christmas Tree star cluster. via NASA https://ift.tt/39CDPst

Mar 9, 2020

Milky Way and Zodiacal Light over Chile Milky Way and Zodiacal Light over Chile


What is the band of light connecting the ground to the Milky Way? Zodiacal light -- a stream of dust that orbits the Sun in the inner Solar System. It is most easily seen just before sunrise, where it has been called a false dawn, or just after sunset. The origin of zodiacal dust remains a topic of research, but is hypothesized to result from asteroid collisions and comet tails. The featured wide-angle image shows the central band of our Milky Way Galaxy arching across the top, while the Large Magellanic Cloud (LMC), a satellite galaxy to our Milky Way, is visible on the far left. The image is a combination of over 30 exposures taken last July near La Serena among the mountains of Chile. During the next two months, zodiacal light can appear quite prominent in northern skies just after sunset. via NASA https://ift.tt/3aFdxWC

Mar 8, 2020

Wolf Rayet Star 124: Stellar Wind Machine Wolf Rayet Star 124: Stellar Wind Machine


Some stars explode in slow motion. Rare, massive Wolf-Rayet stars are so tumultuous and hot that they are slowly disintegrating right before our telescopes. Glowing gas globs each typically over 30 times more massive than the Earth are being expelled by violent stellar winds. Wolf-Rayet star WR 124, visible near the featured image center spanning six light years across, is thus creating the surrounding nebula known as M1-67. Details of why this star has been slowly blowing itself apart over the past 20,000 years remains a topic of research. WR 124 lies 15,000 light-years away towards the constellation of the Arrow (Sagitta). The fate of any given Wolf-Rayet star likely depends on how massive it is, but many are thought to end their lives with spectacular explosions such as supernovas or gamma-ray bursts. via NASA https://ift.tt/330qF5P

Mar 7, 2020

Pic du Midi Panorama Pic du Midi Panorama


A surreal night skyscape, this panorama stitched from 12 photos looks to the west at an evening winter sky over Pic du Midi Observatory, Pyrenees Mountains, Planet Earth. Telescope domes and a tall communications tower inhabit the rugged foreground. On the right, lights from Tarbes, France about 35 kilometers away impinge on the designated dark sky site though, but more distant terrestrial lights seen toward the left are from cities in Spain. Stars and nebulae of the northern winter's Milky Way arc through the sky above. Known to the planet's night skygazers, the Pleiades and Hyades star clusters still hang over the western horizon near center. Captured in mid February the familiar stars of the constellation Orion are to the left and include the no longer fainting star Betelgeuse. via NASA https://ift.tt/3aBkEPO

Mar 6, 2020

Mars Panorama from Curiosity Mars Panorama from Curiosity


The Mars Rover named Curiosity recorded high-resolution, 360 degree views of its location on Mars late last year. The panoramic scene was stitched from over 1,000 images from Curiosity's Mast camera or Mastcam. In this version, captured with Mastcam's medium angle lens, the rover's deck and robotic arm are in the foreground, stretched and distorted by the extreme wide perspective. Just beyond the rover are regions of clay rich rock, evidence for an ancient watery environment, with a clear view toward more distant martian ridges and buttes. Gale crater wall runs across the center (toward the north) in the background over 30 kilometers in the distance. The upper reaches of Mt. Sharp are at the far right. Images to construct the panorama were recorded over 4 consecutive sols between local noon and 2pm to provide consistent lighting. Zoom in to the panoramic scene and you can easily spot the shadow casting sundial mounted on rover's deck (right). In July NASA plans to launch a new rover to Mars named Perseverance. via NASA https://ift.tt/3ay327u

Mar 5, 2020

The Light, the Dark, and the Dusty The Light, the Dark, and the Dusty


This colorful skyscape spans about four full moons across nebula rich starfields along the plane of our Milky Way Galaxy in the royal northern constellation Cepheus. Near the edge of the region's massive molecular cloud some 2,400 light-years away, bright reddish emission region Sharpless (Sh) 155 is left of center, also known as the Cave Nebula. About 10 light-years across the cosmic cave's bright walls of gas are ionized by ultraviolet light from the hot young stars around it. Dusty blue reflection nebulae, like vdB 155 at lower right, and dense obscuring clouds of dust also abound on the interstellar canvas. Astronomical explorations have revealed other dramatic signs of star formation, including the bright red fleck of Herbig-Haro (HH) 168. Below center in the frame, the Herbig-Haro object emission is generated by energetic jets from a newborn star. via NASA https://ift.tt/2vESTHc

Mar 3, 2020

Apollo 13 Views of the Moon Apollo 13 Views of the Moon


What if the only way to get back to Earth was to go around the far side of the Moon? Such was the dilemma of the Apollo 13 Crew in 1970 as they tried to return home in their unexpectedly damaged spacecraft. With the Moon in the middle, their perilous journey substituted spectacular views of the lunar farside for radio contact with NASA's Mission Control. These views have now been digitally recreated from detailed images of the Moon taken by the robotic Lunar Reconnaissance Orbiter. The featured video starts by showing Earth disappear behind a dark lunar limb, while eight minutes later the Sun rises around the opposite side of the Moon and begins to illuminate the Moon's unusual and spectacularly cratered surface. Radio contact was only re-established several minutes after that, as a crescent Earth rose into view. With the gravity of the Moon and the advice of many industrious NASA engineers and scientists, a few days later Apollo 13 opened its parachutes over the Pacific Ocean and landed safely back on Earth. via NASA https://ift.tt/3anXM6i

Mar 2, 2020

Sharpless 308: The Dolphin Nebula Sharpless 308: The Dolphin Nebula


Blown by fast winds from a hot, massive star, this cosmic bubble is much larger than the dolphin it appears to be. Cataloged as Sharpless 2-308 it lies some 5,200 light-years away toward the constellation of the Big Dog (Canis Major) and covers slightly more of the sky than a Full Moon. That corresponds to a diameter of 60 light-years at its estimated distance. The massive star that created the bubble, a Wolf-Rayet star, is the bright one near the center of the nebula. Wolf-Rayet stars have over 20 times the mass of the Sun and are thought to be in a brief, pre-supernova phase of massive star evolution. Fast winds from this Wolf-Rayet star create the bubble-shaped nebula as they sweep up slower moving material from an earlier phase of evolution. The windblown nebula has an age of about 70,000 years. Relatively faint emission captured in the featured expansive image is dominated by the glow of ionized oxygen atoms mapped to a blue hue. via NASA https://ift.tt/2I8ZTyF

Mar 1, 2020

A Hole in Mars A Hole in Mars


What created this unusual hole in Mars? The hole was discovered by chance in 2011 on images of the dusty slopes of Mars' Pavonis Mons volcano taken by the HiRISE instrument aboard the robotic Mars Reconnaissance Orbiter currently circling Mars. The hole, shown in representative color, appears to be an opening to an underground cavern, partly illuminated on the image right. Analysis of this and follow-up images revealed the opening to be about 35 meters across, while the interior shadow angle indicates that the underlying cavern is roughly 20 meters deep. Why there is a circular crater surrounding this hole remains a topic of speculation, as is the full extent of the underlying cavern. Holes such as this are of particular interest because their interior caves are relatively protected from the harsh surface of Mars, making them relatively good candidates to contain Martian life. These pits are therefore prime targets for possible future spacecraft, robots, and even human interplanetary explorers. via NASA https://ift.tt/2T8SqWB