Many spiral galaxies have bars across their centers. Even our own Milky Way Galaxy is thought to have a modest central bar. Prominently barred spiral galaxy NGC 6217, featured here, was captured in spectacular detail in this image taken by the Advanced Camera for Surveys on the orbiting Hubble Space Telescope in 2009. Visible are dark filamentary dust lanes, young clusters of bright blue stars, red emission nebulas of glowing hydrogen gas, a long bar of stars across the center, and a bright active nucleus that likely houses a supermassive black hole. Light takes about 60 million years to reach us from NGC 6217, which spans about 30,000 light years across and can be found toward the constellation of the Little Bear (Ursa Minor). via NASA https://ift.tt/bjLNSv9

Sometimes both heaven and Earth erupt. Colorful auroras erupted unexpectedly a few years ago, with green aurora appearing near the horizon and brilliant bands of red aurora blooming high overhead. A bright Moon lit the foreground of this picturesque scene, while familiar stars could be seen far in the distance. With planning, the careful astrophotographer shot this image mosaic in the field of White Dome Geyser in Yellowstone National Park in the western USA. Sure enough, just after midnight, White Dome erupted — spraying a stream of water and vapor many meters into the air. Geyser water is heated to steam by scalding magma several kilometers below, and rises through rock cracks to the surface. About half of all known geysers occur in Yellowstone National Park. Although the geomagnetic storm that caused the auroras subsided within a day, eruptions of White Dome Geyser continue about every 30 minutes. via NASA https://ift.tt/aHP4Fxl

The spiky stars in the foreground of this backyard telescopic frame are well within our own Milky Way Galaxy. But the two eye-catching galaxies lie far beyond the Milky Way, at a distance of over 300 million light-years. Their distorted appearance is due to gravitational tides as the pair engage in close encounters. Cataloged as Arp 273 (also as UGC 1810), the galaxies do look peculiar, but interacting galaxies are now understood to be common in the universe. Nearby, the large spiral Andromeda Galaxy is known to be some 2 million light-years away and approaching the Milky Way. The peculiar galaxies of Arp 273 may offer an analog of their far future encounter. Repeated galaxy encounters on a cosmic timescale can ultimately result in a merger into a single galaxy of stars. From our perspective, the bright cores of the Arp 273 galaxies are separated by only a little over 100,000 light-years. via NASA https://ift.tt/BeX5bDd

Galactic or open star clusters are young. The swarms of stars are born together near the plane of the Milky Way, but their numbers steadily dwindle as cluster members are ejected by galactic tides and gravitational interactions. Caught in this telescopic frame over three degrees across are three good examples of galactic star clusters, seen toward the southern sky’s nautical constellation Puppis. Below and left, M46 is some 5,500 light-years in the distance. Right of center M47 is only 1,600 light-years away and NGC 2423 (top) is about 2500 light-years distant. Around 300 million years young M46 contains a few hundred stars in a region about 30 light-years across. Sharp eyes can spot a planetary nebula, NGC 2438, at about 11 o’clock against the M46 cluster stars. But that nebula’s central star is billions of years old, and NGC 2438 is likely a foreground object only by chance along the line of sight to youthful M46. Even younger, aged around 80 million years, M47 is a smaller and looser star cluster spanning about 10 light-years. Star cluster NGC 2423 is pushing about 750 million years in age though. NGC 2423 is known to harbor an extrasolar planet, detected orbiting one of its red giant stars. via NASA https://ift.tt/gQtBVkc

Dark markings and bright nebulae in this telescopic southern sky view are telltale signs of young stars and active star formation. They lie a mere 650 light-years away, at the boundary of the local bubble and the Chamaeleon molecular cloud complex. Regions with young stars identified as dusty reflection nebulae from the 1946 Cederblad catalog include the C-shaped Ced 110 just above and left of center, and bluish Ced 111 below it. Also a standout in the frame, the orange tinted V-shape of the Chamaeleon Infrared Nebula (Cha IRN) was carved by material streaming from a newly formed low-mass star. The well-composed image spans 1.5 degrees. That’s about 17 light-years at the estimated distance of the nearby Chamaeleon I molecular cloud. via NASA https://ift.tt/jo8yfiG

What’s that on the Sun? Although it may look like a flowing version of the Eiffel Tower, it is a solar prominence that is actually much bigger — about the height of Jupiter. The huge prominence emerged about ten days ago, hovered over the Sun’s surface for about two days, and then erupted — throwing a coronal mass ejection (CME) into the Solar System. The featured video, captured from the astrophotographer’s backyard in Hendersonville, Tennessee, USA, shows an hour time-lapse played both forwards and backwards. That CME did not impact the Earth, but our Sun had unleashed other recent CMEs that not only triggered Earthly auroras, but puffed out the Earth’s atmosphere enough to cause just-launched Starlink satellites to fall back. Activity on the Sun, including sunspots, prominences, CMEs and flares, continues to increase as the Sun evolves away from a deep minimum in its 11-year magnetic cycle. via NASA https://ift.tt/dEHlyIa

What’s different about this Moon? It’s the terminators. In the featured image, you can’t directly see any terminator — the line that divides the light of day from the dark of night. That’s because the image is a digital composite of 29 near-terminator lunar strips. Terminator regions show the longest and most prominent shadows — shadows which, by their contrast and length, allow a flat photograph to appear three-dimensional. The original images and data were taken near the Moon by NASA’s Lunar Reconnaissance Orbiter. Many of the Moon’s craters stand out because of the shadows they all cast to the right. The image shows in graphic detail that the darker regions known as maria are not just darker than the rest of the Moon — they are flatter. via NASA https://ift.tt/4YoDwhJ

What excites the Heart Nebula? First, the large emission nebula dubbed IC 1805 looks, in whole, like a human heart. Its shape perhaps fitting of the Valentine’s Day, this heart glows brightly in red light emitted by its most prominent element: excited hydrogen. The red glow and the larger shape are all created by a small group of stars near the nebula’s center. In the heart 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 the mythological Queen of Aethiopia (Cassiopeia). via NASA https://ift.tt/HPMhxl8

This is what the Earth looks like at night. Can you find your favorite country or city? Surprisingly, city lights make this task quite possible. Human-made lights highlight particularly developed or populated areas of the Earth’s surface, including the seaboards of Europe, the eastern United States, and Japan. Many large cities are located near rivers or oceans so that they can exchange goods cheaply by boat. Particularly dark areas include the central parts of South America, Africa, Asia, and Australia. The featured image, nicknamed Black Marble, is actually a composite of hundreds of pictures remade in 2016 from data taken by the orbiting Suomi NPP satellite. via NASA https://ift.tt/FVPoNig

The ice was singing as light from a bright gibbous Moon cast shadows across this frozen lake, about 20 kilometers north of Stockholm, Sweden, planet Earth. In the alluring night skyscape captured on February 10, shimmering auroral curtains of light dance in the evening sky. On that northern night nature’s performance included the auroral displays fostered by a minor geomagnetic storm. Stormy space weather was the result of a coronal mass ejection, erupting from a solar prominence days earlier and brushing our fair planet’s magnetosphere. via NASA https://ift.tt/dum2ZBD