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2019 March 19 Abell 370: Galaxy Cluster Gravitational Lens Image Credit: NASA, ESA, Hubble; Processing & Copyright: Rogelio Bernal Andreo (DeepSkyColors.com) Explanation: What are those strange arcs? While imaging the cluster of galaxies Abell 370, astronomers noticed an unusual arc. The arc wasn’t understood right away — not until better images showed that the arc was a previously unseen type of astrophysical artifact of a gravitational lens, where the lens was the center of an entire cluster of galaxies. Today, we know that this arc, the brightest arc in the cluster, actually consists of two distorted images of a fairly normal galaxy that happens to lie far in the distance. Abell 370’s gravity caused the background galaxies’ light — and others — to spread out…

2019 March 18 Horsehead and Orion Nebulas Image Credit & Copyright: Mario Zauner Explanation: The dark Horsehead Nebula and the glowing Orion Nebula are contrasting cosmic vistas. Adrift 1,500 light-years away in one of the night sky’s most recognizable constellations, they appear in opposite corners of the above stunning two-panel mosaic. The familiar Horsehead nebula appears as a dark cloud on the lower left, a small silhouette notched against the glow of hydrogen (alpha) gas, here tinted orange. Alnitak is the easternmost star in Orion’s belt and can be found to the left of the Horsehead. Below Alnitak is the Flame Nebula, with clouds of bright emission and dramatic dark dust lanes. The magnificent emission region, the Orion Nebula (aka M42), lies at the upper…

2019 March 17 M106: A Spiral Galaxy with a Strange Center Image Credit: NASA, ESO , NAOJ, Giovanni Paglioli; Assembling and Processing: R. Colombari and R. Gendler Explanation: What’s happening at the center of spiral galaxy M106? A swirling disk of stars and gas, M106’s appearance is dominated by blue spiral arms and red dust lanes near the nucleus, as shown in the featured image. The core of M106 glows brightly in radio waves and X-rays where twin jets have been found running the length of the galaxy. An unusual central glow makes M106 one of the closest examples of the Seyfert class of galaxies, where vast amounts of glowing gas are thought to be falling into a central massive black hole. M106, also designated…

2019 March 16 NGC 3324 in Carina Image Credit & Copyright: Martin Pugh Explanation: This bright cosmic cloud was sculpted by stellar winds and radiation from the hot young stars of open cluster NGC 3324. With dust clouds in silhouette against its glowing atomic gas, the pocket-shaped star-forming region actually spans about 35 light-years. It lies some 7,500 light-years away toward the nebula rich southern constellation Carina. A composite of narrowband image data, the telescopic view captures the characteristic emission from ionized sulfur, hydrogen, and oxygen atoms mapped to red, green, and blue hues in the popular Hubble Palette. For some, the celestial landscape of bright ridges of emission bordered by cool, obscuring dust along the right side create a recognizable face in profile. The…

2019 March 15 A View Toward M101 Image Credit & Copyright: Christoph Kaltseis, CEDIC 2019 Explanation: Big, beautiful spiral galaxy M101 is one of the last entries in Charles Messier’s famous catalog, but definitely not one of the least. About 170,000 light-years across, this galaxy is enormous, almost twice the size of our own Milky Way galaxy. M101 was also one of the original spiral nebulae observed by Lord Rosse’s large 19th century telescope, the Leviathan of Parsontown. M101 shares this modern telescopic field of view with more distant background galaxies, foreground stars within the Milky Way, and a companion dwarf galaxy NGC 5474 (lower right). The colors of the Milky Way stars can also be found in the starlight from the large island universe….

2019 March 14 Perseverance Valley Panorama Image Credit: NASA JPL-Caltech Cornell ASU Explanation: Mars exploration rover Opportunity’s parting panorama from Perseverance Valley spans 360 degrees in this false color mosaic. The scene is composed of 354 individual images recorded through 3 different color filters by the rover’s panoramic camera from May 13 through June 10, 2018. A few frames remain in black and white at the lower left though. Those were obtained through only one filter just before a dust storm engulfed Mars in June 2018, ultimately ending the solar-powered rover’s trailblazing 15 year mission. Just right of center, the annotation identifies Opportunity’s entry point to Perseverance Valley along the Endeavor crater’s western rim. The rover’s tracks begin there, extending from over the horizon toward…

2019 March 13 Highlights of the North Spring Sky Image Credit & Copyright: Universe2go.com Explanation: What can you see in the night sky this season? The featured graphic gives a few highlights for Earth’s northern hemisphere. Viewed as a clock face centered at the bottom, early (northern) spring sky events fan out toward the left, while late spring events are projected toward the right. Objects relatively close to Earth are illustrated, in general, as nearer to the cartoon figure with the telescope at the bottom center — although almost everything pictured can be seen without a telescope. As happens during any season, constellations appear the same year to year, and, as usual, the Lyrids meteor shower will peak in mid-April. Also as usual, the International…

2019 March 12 Touchdown on Asteroid Ryugu Video Credit: JAXA Explanation: Last month, humanity bounced a robot off an asteroid. The main reason was to collect a surface sample. Despite concern over finding a safely reboundable touchdown spot, Japan’s robotic Hayabusa2 spacecraft successfully touched down — and bounced right back from — asteroid Ryugu. Before impact, Hayabusa2 fired a small bullet into 162173 Ryugu to scattered surface material and increase the chance that Hayabusa2 would be able to capture some. Next month, Hayabusa2 will fire a much larger bullet into Ryugu in an effort to capture sub-surface material. Near the end of this year, Hayabusa2 is scheduled to depart Ryugu and begin a looping trip back to Earth, hopefully returning small pieces of this near-Earth…

2019 March 11 The Central Magnetic Field of the Cigar Galaxy Image Credit: NASA, SOFIA, E. Lopez-Rodriguez; NASA, Spitzer, J. Moustakas et al. Explanation: Are galaxies giant magnets? Yes, but the magnetic fields in galaxies are typically much weaker than on Earth’s surface, as well as more complex and harder to measure. Recently, though, the HAWC+ instrument onboard the airborne (747) SOFIA observatory has been successful in detailing distant magnetic fields by observing infrared light polarized by reflection from dust grains. Featured here, HAWC+ observations of the M82, the Cigar galaxy, show that the central magnetic field is perpendicular to the disk and parallel to the strong supergalactic wind. This observation bolsters the hypothesis that M82’s central magnetic field helps its wind transport the mass…

2019 March 10 Moonrise Through Mauna Kea’s Shadow Images Credit & Copyright: Michael Connelley (U. Hawaii) Explanation: How can the Moon rise through a mountain? It cannot — what was photographed here is a moonrise through the shadow of a large volcano. The volcano is Mauna Kea, Hawai’i, USA, a frequent spot for spectacular photographs since it is one of the premier observing locations on planet Earth. The Sun has just set in the opposite direction, behind the camera. Additionally, the Moon has just passed full phase — were it precisely at full phase it would rise, possibly eclipsed, at the very peak of the shadow. The Moon is actually rising in the triangular shadow cone of the volcano, a corridor of darkness that tapers…