APOD: 2022 January 2 - Quadruple Lunar Halo Over Winter Road Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. 2022 January 2 Quadruple Lunar Halo Over Winter Road Image Credit & Copyright: Dani Caxete Explanation: Sometimes falling ice crystals make the atmosphere into a giant lens causing arcs and halos to appear around the Sun or Moon.One Saturday night in 2012 was just such a time nearMadrid,Spain,where a winter sky displayed not only a bright Moon but four rare lunar halos. The brightest object, near the top of the featured image, is the Moon.Light from the Moonrefracts through tumbling hexagonal ice crystals into a somewhat rare22-degree haloseen surrounding the Moon.Elongating the 22-degree arc horizontally is a more rare circumscribed halo caused by column ice crystals.Even more rare, some moonlight refracts through more distant tumbling ice crystals to form a (third)rainbow-like arc 46 degrees from the Moon and appearing here just above a picturesque winter landscape.Furthermore, part of a whole 46-degree circular halo is also visible, so that an extremely rare -- especially for the Moon -- quadruple halo was captured.Far in the background is a...
APOD: 2022 January 1 - The Full Moon of 2021 Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. 2022 January 1 The Full Moon of 2021 Image Credit &Copyright:Soumyadeep Mukherjee Explanation: Every Full Moon of 2021 shines in this year-spanning astrophoto project,a composite portrait ofthe familiar lunar nearside at each brightestlunar phase.Arranged by moonth,the year progresses in stripes beginning at the top.Taken with the same camera and lens the stripes are from Full Moonimages all combined at the same pixel scale.The stripes still looked mismatched, but they showthat the Full Moon's angular size changes throughout the yeardepending on itsdistance from Kolkata, India, planet Earth.The calendar month,a full moon name, distance in kilometers, and angularsize is indicated for each stripe.Angular size is given in minutes of arc corresponding to 1/60th of a degree.The largest Full Moon isnear a perigee or closest approachin May.The smallest isnear an apogee,the most distant Full Moon in December.Of course the full moons ofMay and Novemberalso slid into Earth's shadowduring 2021's two lunar eclipses. Tomorrow's picture: bright moon halos<| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| > Authors...
APOD: 2021 December 31 - JWST on the Road to L2 Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. 2021 December 31 JWST on the Road to L2 Image Credit &Copyright:Malcolm Park(North York Astronomical Association) Explanation: This timelapse gif tracks theJames Webb Space Telescope asit streaks across the stars of Orion on its journey to a destinationbeyond the Moon.Recorded on December 28, 12 consecutive exposures each 10 minutes longwere aligned and combined with a subsequent color image of the background starsto create the animation.About 2.5 days after its December 25 launch, JWST cruised pastthe altitudeof the Moon's orbit as it climbed up the gravity ridgefrom Earth to reach a halo orbit around L2, anEarth-Sun Lagrange point.Lagrange points are convenient locations in space wherethe combined gravitational attraction of one massive body (Earth)orbiting another massive body (Sun)is in balance with the centripetal force needed tomove along with them.So much smaller masses, like spacecraft, will tend to staythere.One of 5 Lagrange points, L2 is about 1.5 million kilometers from Earthdirectly along the Earth-Sun line.JWST will arrive at L2 on January 23, 29 days after launch.While relaxing in Earth's...
APOD: 2021 December 30 - The Further Tail of Comet Leonard Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. 2021 December 30 The Further Tail of Comet Leonard Image Credit &Copyright:Daniele Gasparri Explanation: Comet Leonard, brightest comet of 2021,is at the lower left of these two panelscaptured on December 29 in dark Atacama desert skies.Heading for its perihelion on January 3Comet Leonard's visible tailhas grown.Stacked exposures with a wide angle lens(also displayed in a reversed B/W scheme for contrast),trace the complicated ion tail for an amazing 60 degrees, withbright Jupiter shining near the horizon at lower right.Material vaporizingfrom Comet Leonard's nucleus,a mass of dust, rock, and ices about 1 kilometer across,has produced the long tail of ionized gas fluorescing in the sunlight.Likely flares on thecomet's nucleusand buffeting by magnetic fields and the solar wind in recent weekshave resulted in the tail's irregularpinched and twisted appearance.Still days from its closest approach to the Sun,Comet Leonard's activityshould continue.The comet issouth of the Solar System'secliptic plane as it sweeps through the southern constellation Microscopium. Tomorrow's picture: L2 road trip<| Archive| Submissions | Index| Search| Calendar| RSS| Education| About...
APOD: 2021 December 29 - Giant Storms and High Clouds on Jupiter Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. 2021 December 29 Giant Storms and High Clouds on Jupiter Image Credit: NASA/JPL-Caltech/SwRI/MSSS;Processing & License:Kevin M. Gill Explanation: What and where are these large ovals?They are rotating storm clouds on Jupiter imaged last month by NASA's Juno spacecraft.In general, higher clouds are lighter in color, and the lightest clouds visible are the relatively small clouds that dot the lower oval.At 50 kilometers across, however, even these light clouds are not small. They are so high up that they cast shadows on the swirling oval below.The featured image has been processed to enhance color and contrast.Large ovals are usually regions of high pressure that span over 1000 kilometers and can last for years.The largest oval on Jupiter is the Great Red Spot (not pictured), which has lasted for at least hundreds of years.Studying cloud dynamics on Jupiter with Juno images enables a better understanding of dangerous typhoons and hurricanes on Earth. Follow APOD in English on: Facebook, Instagram, Podcast,Reddit, or Twitter Tomorrow's picture: farther along <|...
APOD: 2021 December 28 - Sun Halo over Sweden Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. Sun Halo over Sweden Video Credit & Copyright: Håkan Hammar (Vemdalen Ski Resort, SkiStar) Explanation: What's happened to the Sun? Sometimes it looks like the Sun is being viewed through a giant lens. In the featured video, however, there are actually millions of tiny lenses: ice crystals. Water may freeze in the atmosphere into small, flat, six-sided, ice crystals. As these crystals flutter to the ground, much time is spent with their faces flat and parallel to the ground. An observer may find themselves in the same plane as many of the falling ice crystals near sunrise or sunset. During this alignment, each crystal can act like a miniature lens, refracting sunlight into our view and creating phenomena like parhelia, the technical term for sundogs. The featured video was taken in late 2017 on the side of a ski hill at the Vemdalen Ski Resort in central Sweden.Visible in the center is the most direct image of the Sun, while two bright sundogs glow prominently from both the...
APOD: 2021 December 27 - Comet Leonard behind JWST Launch Plume Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. 2021 December 27 Comet Leonard behind JWST Launch Plume Image Credit & Copyright: Matipon Tangmatitham (NARIT) Explanation: Which one of these two streaks is a comet?Although they both have comet-like features, the lower streak is the only real comet.This lower streak shows the coma and tail of Comet Leonard, a city-sized block of rocky ice that is passing through the inner Solar System as it continues its looping orbit around the Sun. Comet Leonard has recently passed its closest to both the Earth and Venus and will round the Sun next week. The comet, still visible to the unaided eye, has developed a long and changing tail in recent weeks. In contrast, the upper streak is the launch plume of the Ariane V rocket that lifted the James Webb Space Telescope (JWST) off the Earth two days ago.The featured single-exposure image was taken from Thailand, and the foreground spire is atop a pagoda in Doi Inthanon National Park.JWST, NASA's largest and most powerful space telescope so...
APOD: 2021 December 26 - James Webb Space Telescope over Earth Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. 2021 December 26 James Webb Space Telescope over Earth Image Credit: Arianespace, ESA, NASA, CSA, CNES Explanation: There's a big new telescope in space.This one, the James Webb Space Telescope (JWST), not only has a mirror over five times larger than Hubble's in area, but can see better in infrared light.The featured picture shows JWST high above the Earth just after being released by the upper stage of an Ariane V rocket, launched yesterday from French Guiana.Over the next month, JWST will move out near the Sun-Earth L2 point where it will co-orbit the Sun with the Earth.During this time and for the next five months, JWST will unravel its segmented mirror and an array of sophisticated scientific instruments -- and test them.If all goes well, JWST will start examining galaxies across the universe and planets orbiting stars across our Milky Way Galaxy in the summer of 2022. APOD Gallery: Webb Space Telescope Launch Tomorrow's picture: comet webb <| Archive| Submissions | Index| Search| Calendar| RSS|...
APOD: 2021 December 25 - The Tail of a Christmas Comet Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. 2021 December 25 The Tail of a Christmas Comet Image Credit &Copyright:Rolando Ligustri(CARA Project,CAST)andLukas Demetz Explanation: The tail of a cometstreams across this three degree wide telescopicfield of view captured under dark Namibian skies on December 21.In outburst only a few days ago and just reachingnaked eye visibilityComet Leonard(C/2021 A1) is this year's brightest comet.Binoculars will make the diffuse comet easier to spot though, close tothe western horizon after sunset.Details revealed in the sharp image show the comet's coma with agreenish tinge, andfollow the interaction of the comet'sion tailwith magnetic fields in the solar wind.After passing closest to Earth on December 12 and Venus on December 18,Comet Leonard is heading toward perihelion,its closest approach to the Sun on January 3rd.Appearing in late December'sbeautiful evening skiesComet Leonardhas also become known as 2021's Christmas Comet. Launch Update: James Webb Space Telescope Tomorrow's picture: dawn of a new space telescope<| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| > Authors & editors: Robert Nemiroff(MTU) &Jerry Bonnell...
APOD: 2021 December 24 - M1: The Crab Nebula Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. 2021 December 24 M1: The Crab Nebula Image Credit &Copyright:Michael Sherick Explanation: The Crab Nebula is cataloged as M1, the first object onCharles Messier'sfamous 18th century list of things which are not comets.In fact,the Crabis now known to be asupernova remnant,debris from the death explosion of a massive star,witnessedby astronomers in the year 1054.This sharp, ground-basedtelescopic view combines broadband color data withnarrowband data that tracks emission from ionized sulfur, hydrogen, andoxygen atoms to explore the tangled filaments withinthe still expanding cloud.One of the most exotic objects known to modern astronomers,the Crab Pulsar,a neutron star spinning 30 times a second,is visible as a bright spot nearthe nebula's center.Like a cosmic dynamo,this collapsed remnant of the stellar corepowers the Crab's emission across the electromagnetic spectrum.Spanning about 12 light-years, the Crab Nebula is a mere6,500 light-years away in theconstellation Taurus. Launch Update: James Webb Space Telescope Tomorrow's picture: A Christmas Comet<| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| > Authors & editors: Robert Nemiroff(MTU) &Jerry Bonnell (UMCP)NASA...
APOD: 2021 December 23 - Three Planets and a Comet Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. 2021 December 23 Three Planets and a Comet Image Credit &Copyright:Tunc Tezel(TWAN) Explanation: Are you still looking for thatperfect holiday gift for an astronomer?If your night sky is dark and horizon clear enough,the Solar Systemmay have done your shopping for you.Send them outside after sunset to see three planets and a comet.In this snapshot of the December solstice evening sky from thevillage of Kirazli, Turkeythe brightest celestial beacon is Venus, close to the southwestern horizonat the right.Look left and up to find Saturn shining between clouds.Follow that linefarther left and up to bright Jupiter, the Solar System'sruling gas giant.This year's surprise visitor to the inner Solar System, Comet Leonard(C/2021 A1), is near the horizon too.The comet is fainterbut forms a nearly equilateral trianglewith planets Venus and Saturn in this view.After adramatic brighteningin recent daysthe comet is just visible to the unaided eye, though a nice pair ofbinoculars is alwaysa good idea. Notable Submissions to APOD: Planetary Alignment: 2021 December Tomorrow's picture: pixels in space<| Archive| Submissions |...
APOD: 2021 December 22 - Launch of the IXPE Observatory Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. 2021 December 22 Launch of the IXPE Observatory Image Credit & Copyright: Jordan Sirokie Explanation: Birdsdon't fly this high. Airplanes don't go this fast. The Statue of Libertyweighs less. No species other than human can even comprehend what is going on,nor could any human just a millennium ago.The launch of arocket bound for space is an event thatinspires awe and challenges description. Pictured here, a SpaceX Falcon 9 rocket lifted off from Kennedy Space Center, Florida earlier this month carrying the Imaging X-ray Polarimetry Explorer (IXPE). IXPE is scheduled to observe high-energy objects such as neutron stars, black holes, and the centers of distant galaxies to better determine the physics and geometries that create and control them. From a standing start, the 300,000+ kilogramrocket ship lifted IXPE up to circle theEarth, where theoutside air is too thin to breathe.Rockets bound for space are nowlaunched from somewhere on Earthevery few days. Launch Update: James Webb Space Telescope Tomorrow's picture: Three Planets and a Comet <| Archive| Submissions |...
APOD: 2021 December 21 - Solstice Sun and Milky Way Discover the cosmos!Each day a different image or photograph of our fascinating universe isfeatured, along with a brief explanation written by a professional astronomer. 2021 December 21 Solstice Sun and Milky Way Composite Image Credit &Copyright: Stefan Seip(TWAN) Explanation: Welcome to December's solstice, first day of winter in the north andsummer for the southern hemisphere.Astronomical markers of the seasons,solstice and equinoxdates are based on the Sun's place in its annual journey along the ecliptic, through planet Earth's sky.At this solstice, the Sun reaches its maximum southern declination of -23.5 degrees today at 15:59 UTC, while its right ascension coordinate on thecelestial sphereis 18 hours.That puts the Sun in the constellation Sagittarius in a direction nearthe center of our Milky Way galaxy.In fact, if you could see today's Solstice Sun against faint background stars and nebulae (that's really hard to do, especially in the daytime ...)your view might look something like this composited panorama.To make it, images ofour fair galaxywere taken under dark Namibian night skies, then stitched together in a panoramic view.From a snapshot made on 2015 December 21, the Sun was digitally overlayed as a brilliant star at today's northern...