Mom, Vaper, Diabetic, Crazy Cat Lady

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Island Universe, Cosmic Sand

Stars in our own Milky Way Galaxy are scattered through this eye-catching field of view. From the early hours after midnight on August 13, the 30 second exposure of the night sky over Busko-Zdroj, Poland records the colorful and bright trail of a Perseid meteor. Seen near the peak of the annual Perseid meteor shower it flashes from lower left to upper right. The hurtling grain of cosmic sand, a piece of dust from periodic comet Swift-Tuttle, vaporized as it passed through planet Earth’s atmosphere at almost 60 kilometers per second. Just above and right of center, well beyond the stars of the Milky Way, lies the island universe known as M31 or the Andromeda Galaxy. The Andromeda Galaxy is the most distant object easily visible to the naked-eye, about 2.5 million light-years away. The visible meteor trail begins only about 100 kilometers above Earth’s surface, though. It points back to the meteor shower radiant in the constellation Perseus off the lower left edge of the frame. Follow this bright perseid meteor trail below and left to the stars of NGC 869and NGC 884, the double star cluster in Perseus. via NASA https://apod.nasa.gov/apod/ap210814.html

A Perfect Spiral

If not perfect then this spiral galaxy is at least one of the most photogenic. An island universe of about 100 billion stars, 32 million light-years away toward the constellation Pisces, M74 presents a gorgeous face-on view. Classified as an Sc galaxy, the grand design of M74’s graceful spiral arms are traced by bright blue star clusters and dark cosmic dust lanes. This sharp composite was constructed from image data recorded by the Hubble Space Telescope’s Advanced Camera for Surveys. Spanning about 30,000 light-years across the face of M74, it includes exposures recording emission from hydrogen atoms, highlighting the reddish glow of the galaxy’s large star-forming regions. With a lower surface brightness than most galaxies in the Messier catalog, M74 is sometimes known as the Phantom Galaxy. via NASA https://apod.nasa.gov/apod/ap210813.html

A Beautiful Trifid

The beautiful Trifid Nebula is a cosmic study in contrasts. Also known as M20, it lies about 5,000 light-years away toward the nebula rich constellation Sagittarius. A star forming region in the plane of our galaxy, the Trifid does illustrate three different types of astronomical nebulae; red emission nebulae dominated by light from hydrogen atoms, blue reflection nebulae produced by dust reflecting starlight, and dark nebulae where dense dust clouds appear in silhouette. But the red emission region roughly separated into three parts by obscuring dust lanes is what lends the Trifid its popular name. Pillars and jets sculpted by newborn stars, below and left of the emission nebula’s center, appear in famous Hubble Space Telescope close-up images of the region. The Trifid Nebula is about 40 light-years across. Just too faint to be seen by the unaided eye, it almost covers the area of a full moon in planet Earth’s sky. via NASA https://apod.nasa.gov/apod/ap210812.html

Mammatus Clouds over Saskatchewan

When do cloud bottoms appear like bubbles? Normally, cloud bottoms are flat. This is because moist warm air that rises and cools will condense into water droplets at a specific temperature, which usually corresponds to a very specific height. As water droplets grow, an opaque cloud forms. Under some conditions, however, cloud pockets can develop that contain large droplets of water or ice that fall into clear air as they evaporate. Such pockets may occur in turbulent air near a thunderstorm. Resulting mammatus clouds can appear especially dramatic if sunlit from the side. The mammatus clouds pictured here, lasting only a few minutes, were photographed over Regina, Saskatchewan, Canada, just after a storm in 2012. via NASA https://apod.nasa.gov/apod/ap210811.html

Fire in Space

What does fire look like in space? In the gravity on Earth, heated air rises and expands, causing flames to be teardrop shaped. In the microgravity of the air-filled International Space Station (ISS), however, flames are spheres. Fire is the rapid acquisition of oxygen, and space flames meet new oxygen molecules when they float by randomly from all directions — creating the enveloping sphere. In the featured image taken in the ISS’s Combustion Integration Rack, a spherical flame envelopes clusters of hot glowing soot. Without oxygen, say in the vacuum of empty space, a fire would go out immediately. The many chemical reactions involved with fire are complex, and testing them in microgravity is helping humanity not only to better understand fire — but how to put out fire, too. via NASA https://apod.nasa.gov/apod/ap210810.html
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