Sharpless 308: The Dolphin Head Nebula

Blown by fast winds from a hot, massive star, this cosmic bubble is huge. Cataloged as Sharpless 2-308 it lies some 5,000 light-years away toward the well-trained constellation 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 by narrowband filters in the deep image is dominated by the glow of ionized oxygen atoms mapped to a blue hue. Presenting a mostly harmless outline, SH2-308 is also known as The Dolphin-head Nebula.

from NASA https://ift.tt/zxR2reK

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A Spiral Aurora over Iceland

What's happened to the sky? Aurora ! Captured in 2015, this aurora was noted by Iceland ers for its great brightness and quick development. The aurora resulted from a solar storm, with high energy particles bursting out from the Sun and through a crack in Earth's protective magnetosphere a few days later. Although a spiral pattern can be discerned, creative human s might imagine the complex glow as an atmospheric apparition of any number of common icons . In the foreground of the featured image is the Ã–lfusÃ¡ River while the lights illuminate a bridge in Selfoss City . Just beyond the low clouds is a nearly full Moon. The liveliness of the Sun -- and likely the resulting auroras on Earth -- is slowly increasing as the Sun emerges from a Solar minimum , a historically quiet period in its 11-year cycle. from NASA https://ift.tt/2XgnyIE

NGC 2419: Intergalactic Wanderer

Stars of the globular cluster NGC 2419 are packed into this Hubble Space Telescope field of view toward the mostly stealthy constellation Lynx . The two brighter spiky stars near the edge of the frame are within our own galaxy. NGC 2419 itself is remote though, some 300,000 light-years away. In comparison, the Milky Way's satellite galaxy, the Large Magellanic Cloud , is only about 160,000 light-years distant. Roughly similar to other large globular star clusters like Omega Centauri , NGC 2419 is intrinsically bright, but appears faint because it is so far away. Its extreme distance makes it difficult to study and compare its properties with other globular clusters that roam the halo of our Milky Way galaxy. Sometimes called "the Intergalactic Wanderer", NGC 2419 really does seem to have come from beyond the Milky Way. Measurements of the cluster's motion through space suggest it once belonged to the Sagittarius dwarf spheroidal galaxy , another small satellite...

SuperCam Target on Maaz

What's the sound of one laser zapping? There's no need to consult a Zen master to find out, just listen to the first acoustic recording of laser shots on Mars . On Mars Rover Perseverance mission sol 12 (March 2, 2021) the SuperCam instrument atop the rover's mast zapped a rock dubbed Ma'az 30 times from a range of about 3.1 meters. Its microphone recorded the soft staccato popping sounds of the rapid series of SuperCam laser zaps. Shockwaves created in the thin Martian atmosphere as bits of rock are vaporized by the laser shots make the popping sounds, sounds that offer clues to the physical structure of the target. This SuperCam close-up of the Ma'az target region is 6 centimeters (2.3 inches) across. Ma'az means Mars in the Navajo language . from NASA https://ift.tt/qUSdeZl

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