[{"copyright":"Rory Gannaway","date":"2024-08-17","explanation":"On August 11 a Rocket Lab Electron rocket launched from a rotating planet. With a small satellite on board its mission was dubbed A Sky Full of SARs (Synthetic Aperture Radar satellites), departing for low Earth orbit from Mahia Peninsula on New Zealand's north island. The fiery trace of the Electron's graceful launch arc is toward the east in this southern sea and skyscape, a composite of 50 consecutive frames taken over 2.5 hours. Fixed to a tripod, the camera was pointing directly at the South Celestial Pole, the extension of planet Earth's axis of rotation in to space. But no bright star marks that location in the southern hemisphere's night sky. Still, the South Celestial Pole is easy to spot. It lies at the center of the concentric star trail arcs that fill the skyward field of view.   Gallery: Perseid Meteor Shower 2024 and Aurorae","hdurl":"https://apod.nasa.gov/apod/image/2408/RocketGannaway.jpg","media_type":"image","service_version":"v1","title":"Sky Full of Arcs","url":"https://apod.nasa.gov/apod/image/2408/RocketGannaway_1100c.jpg"},{"date":"2025-02-19","explanation":"How do stars and planets form? New clues have been found in the protoplanetary system Herbig-Haro 30 by the James Webb Space Telescope in concert with Hubble and the Earth-bound ALMA.  The observations show, among other things, that large dust grains are more concentrated into a central disk where they can form planets. The featured image from Webb shows many attributes of the active HH-30 system. Jets of particles are being expelled vertically, shown in red, while a dark dust-rich disk is seen across the center, blocking the light from the star or stars still forming there. Blue-reflecting dust is seen in a parabolic arc above and below the central disk, although why a tail appears on the lower left is currently unknown. Studying how planets form in HH 30 can help astronomers better understand how planets in our own Solar System once formed, including our Earth.","hdurl":"https://apod.nasa.gov/apod/image/2502/HH30_Webb_960.jpg","media_type":"image","service_version":"v1","title":"HH 30: A Star System with Planets Now Forming","url":"https://apod.nasa.gov/apod/image/2502/HH30_Webb_960.jpg"},{"date":"2019-02-20","explanation":"Carinae may be about to explode.  But no one knows when - it may be next year, it may be one million years from now. Eta Carinae's mass - about 100 times greater than our Sun - makes it an excellent candidate for a full blown supernova. Historical records do show that about 170 years ago Eta Carinae underwent an unusual outburst that made it one of the brightest stars in the southern sky.  Eta Carinae, in the Keyhole Nebula, is the only star currently thought to emit natural LASER light. This featured image brings out details in the unusual nebula that surrounds this rogue star.  Diffraction spikes, caused by the telescope, are visible as bright multi-colored streaks emanating from Eta Carinae's center.  Two distinct lobes of the Homunculus Nebula encompass the hot central region, while some strange radial streaks are visible in red extending toward the image right. The lobes are filled with lanes of gas and dust which absorb the blue and ultraviolet light emitted near the center.  The streaks, however, remain unexplained.","hdurl":"https://apod.nasa.gov/apod/image/1902/EtaCarinae_HubbleSchmidt_1764.jpg","media_type":"image","service_version":"v1","title":"Doomed Star Eta Carinae","url":"https://apod.nasa.gov/apod/image/1902/EtaCarinae_HubbleSchmidt_960.jpg"},{"copyright":"Aman Chokshi","date":"2022-11-05","explanation":"Last May 16 the Moon slid through Earth's shadow, completely immersed in the planet's dark umbra for about 1 hour and 25 minutes during a total lunar eclipse. In this composited timelapse view, the partial and total phases of the eclipse were captured as the Moon tracked above the horizon from Amundsen-Scott South Pole Station. There it shared a cold and starry south polar night with a surging display of the aurora australis and central Milky Way. In the foreground are the BICEP (right) and South Pole telescopes at the southernmost station's Dark Sector Laboratory. But while polar skies can be spectacular, you won't want to go to the South Pole to view the total lunar eclipse coming up on November 8. Instead, that eclipse can be seen from locations in Asia, Australia, the Americas and the Pacific. It will be your last chance to watch a total lunar eclipse until 2025.","hdurl":"https://apod.nasa.gov/apod/image/2211/Lunar-Eclipse-South-Pole.jpg","media_type":"image","service_version":"v1","title":"Lunar Eclipse at the South Pole","url":"https://apod.nasa.gov/apod/image/2211/Lunar-Eclipse-South-Pole_1024.jpg"},{"date":"2003-05-04","explanation":"Many people have heard a sonic boom, but few have seen one. When an airplane travels at a speed faster than sound, density waves of sound emitted by the plane cannot precede the plane, and so accumulate in a cone behind the plane.  When this shock wave passes, a listener hears all at once the sound emitted over a longer period: a sonic boom.  As a plane accelerates to just break the sound barrier, however, an unusual cloud might form.  The origin of this cloud is still debated.  A leading theory is that a drop in air pressure at the plane described by the Prandtl-Glauert Singularity occurs so that moist air condenses there to form water droplets.  Above, an F/A-18 Hornet was  photographed just as it broke the sound barrier.  Large meteors and the space shuttle frequently produce audible sonic booms before they are slowed below sound speed by the Earth's atmosphere.","hdurl":"https://apod.nasa.gov/apod/image/0102/sonicboomplane_navy_big.jpg","media_type":"image","service_version":"v1","title":"A Sonic Boom","url":"https://apod.nasa.gov/apod/image/0102/sonicboomplane_navy.jpg"}]