APOD: 2021 September 6 - Firefly Milky Way over Russia 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 September 6 Firefly Milky Way over Russia Image Credit & Copyright: Anton Komlev Explanation: It started with a pine tree.The idea was to photograph a statuesque pine in front of the central band of our Milky Way Galaxy.And the plan, carried out two months ago, was successful -- they both appear prominently.But the resulting 3-frame panorama captured much more.Colorful stars, for example, dot the distant background, with bright Altair visible on the upper left.The planet Saturn, a bit closer, was captured just over the horizon on the far left.Just beyond the Earth's atmosphere, seen in the upper right, an Earth-orbiting satellite was caught leaving a streak during the 25-second exposure.The Earth's atmosphere itself was surprisingly visible -- as green airglow across the image top.Finally, just by chance, there was a firefly.Do you see it?Near the image bottom, the firefly blinked in yellow several times as it fluttered before the rolling hills above Milogradovka River in Primorsky Krai, Russia. Explore Your Universe: Random APOD Generator Tomorrow's picture:...
APOD: 2021 September 5 - Earth and Moon 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. Earth and Moon Image Credit: NASA, JPL, Galileo Project; Processing & License: Gordan Ugarkovic Explanation: The Earth and Moon are rarely photographed together.One of most spectacular times this occurred was about 30 years ago when the Jupiter-bound Galileo spacecraft zoomed past our home planetary system. Then, robotic Galileo watched from about 15-times the Earth-Moon separation as our only natural satellite glided past our home world. The featured video combines 52 historic color-enhanced images.Although our Moon may appear small next to the Earth, no other planet in our Solar System has a satellite so comparable in size. The Sun, far off to the right, illuminated about half of each sphere, and shows the spinning Earth's white clouds, blue oceans, and tan continents. Tomorrow's picture: firefly milkyway <| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| > Authors & editors: Robert Nemiroff(MTU) &Jerry Bonnell (UMCP)NASA Official: Phillip NewmanSpecific rights apply.NASA WebPrivacy Policy and Important NoticesA service of:ASD atNASA /GSFC& Michigan Tech. U.
APOD: 2021 September 3 - NGC 7023: The Iris 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 September 3 NGC 7023: The Iris Nebula Image Credit &Copyright: Satwant Kumar Explanation: These cosmic clouds have blossomed 1,300 light-years away,in the fertile starfields of theconstellationCepheus.Called the Iris Nebula,NGC 7023is not the only nebulato evoke the imagery of flowers.Still, thisdeep telescopic imageshows off the Iris Nebula's range ofcolors and symmetries, embedded in surroundingfields of interstellar dust.Within the Iris itself, dusty nebular material surrounds a hot,young star.The dominant color of the brighter reflection nebula is blue,characteristic of dust grains reflecting starlight.Central filamentsof the reflection nebula glow with a faint reddishphotoluminesence as some dust grainseffectively convertthe star's invisibleultraviolet radiation to visible red light.Infraredobservationsindicate that this nebula containscomplex carbon molecules known asPAHs.The dusty blue petals of the Iris Nebula span about six light-years. Tomorrow's picture: light-weekend<| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| > Authors & editors: Robert Nemiroff(MTU) &Jerry Bonnell (UMCP)NASA Official: Phillip NewmanSpecific rights apply.NASA WebPrivacy Policy and Important NoticesA service of:ASD atNASA /GSFC& Michigan Tech. U.
APOD: 2021 September 2 - M51: The Whirlpool Galaxy 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 September 2 M51: The Whirlpool Galaxy Image Credit &Copyright: Josep Drudis Explanation: Find the Big Dipper andfollow the handle away from the dipper's bowluntil you get to the last bright star.Then, just slide your telescope a little south and west andyou'llcome upon this stunning pair of interacting galaxies,the 51st entryin Charles Messier's famous catalog.Perhaps theoriginal spiral nebula,the large galaxy withwell defined spiral structure is also cataloged as NGC 5194.Its spiral arms and dust lanesclearly sweep in front of its companion galaxy (top),NGC 5195.The pair are about 31 million light-years distant andofficially lie within the angular boundaries ofthe small constellationCanesVenatici.Though M51 looks faint and fuzzy to the eye,deep images like this onereveal its striking colors and galactictidal debris. Tomorrow's picture: pixels in space<| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| > Authors & editors: Robert Nemiroff(MTU) &Jerry Bonnell (UMCP)NASA Official: Phillip NewmanSpecific rights apply.NASA WebPrivacy Policy and Important NoticesA service of:ASD atNASA /GSFC& Michigan Tech. U.
APOD: 2021 September 1 - Dancing Ghosts: Curved Jets from Active Galaxies 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 September 1 Dancing Ghosts: Curved Jets from Active Galaxies Image Credit: Jayanne English & Ray Norris, EMU-ASKAP, DES; Text: Jayanne English (U. Manitoba) Explanation: Why would galaxies emit jets that look like ghosts? And furthermore, why do they appear to be dancing? The curled and fluffy jets from the supermassive black holes at the centers of two host galaxies (top center and lower left) are unlike anything seen before. They were found by astronomers using the Australian Square Kilometer Array Pathfinder (ASKAP) radio telescope when creating maps tracing the evolution of galaxies. Images preceding this Evolutionary Map of the Universe survey only showed amorphous blobs. Eventually, comparisons of relative amounts of energy emitted revealed the glowing elongated structures were created by electrons streaming around magnetic field lines. Overlaying the radio data on an optical view of the sky (Dark Energy Survey) confirmed that the electron streams originated from the centers of active galaxies.Usually such Active Galactic Nuclei (AGN) produce straight jets. A leading hypothesis...
APOD: 2021 August 31 - A Blue Moon in Exaggerated Colors 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 August 31 A Blue Moon in Exaggerated Colors Image Credit & Copyright: Robert Fedez Explanation: The Moon is normally seen in subtle shades of grey or gold. But small, measurable color differences have been greatly exaggerated to make this telescopic, multicolored, moonscape captured during the Moon's full phase. The different colors are recognized to correspond to real differences in the chemical makeup of the lunar surface. Blue hues reveal titanium rich areas while orange and purple colors show regions relatively poor in titanium and iron. The familiar Sea of Tranquility, or Mare Tranquillitatis, is the blue area toward the upper right. White lines radiate across the orange-hued southern lunar highlands from 85-kilometer wide ray-crater Tycho at bottom right. The full moon that occurred earlier this month could be counted as a seasonal blue moon because it was, unusually, the third of four full moons to occur during northern summer (and hence southern winter). The featured 272-image composite demonstrates that the full Moon is always blue,...
APOD: 2021 August 30 - A Fire Rainbow over West Virginia 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 August 30 A Fire Rainbow over West Virginia Image Credit: Christa Harbig Explanation: What's happening to this cloud?Ice crystals in a distant cirrus cloud are acting like little floating prisms. Known informally as a fire rainbow for its flame-like appearance, a circumhorizon arc appears parallel to the horizon.For a circumhorizontal arc to be visible, the Sun must be at least 58 degrees high in a sky where cirrus clouds present below -- in this case cirrus fibrates. The numerous, flat, hexagonal ice-crystals that compose the cirrus cloud must be aligned horizontally to properly refract sunlight in a collectively similar manner. Therefore, circumhorizontalarcs are somewhat unusual to see. The featured fire rainbow was photographed earlier this month near North Fork Mountain in West Virginia, USA. Tomorrow's picture: true moon blue <| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| > Authors & editors: Robert Nemiroff(MTU) &Jerry Bonnell (UMCP)NASA Official: Phillip NewmanSpecific rights apply.NASA WebPrivacy Policy and Important NoticesA service of:ASD atNASA /GSFC& Michigan...
APOD: 2021 August 29 - Orbits of Potentially Hazardous Asteroids 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 August 29 Orbits of Potentially Hazardous Asteroids Image Credit: NASA, JPL-Caltech Explanation: Are asteroids dangerous?Some are, but the likelihood of a dangerous asteroid striking the Earth during any given year is low.Because some past mass extinction events have been linked to asteroid impacts, however, humanity has made it a priority to find and catalog those asteroids that may one day affect life on Earth.Pictured here are the orbits of the over 1,000 known Potentially Hazardous Asteroids (PHAs).These documented tumbling boulders of rock and ice are over 140 meters across and will pass within 7.5 million kilometers of Earth -- about 20 times the distance to the Moon.Although none of them will strike the Earth in the next 100 years -- not all PHAs have been discovered, and past 100 years, many orbits become hard to predict.Were an asteroid of this size to impact the Earth, it could raise dangerous tsunamis, for example.To investigate Earth-saving strategies, NASA's Double Asteroid Redirection Test (DART) is planned for launch later...
APOD: 2021 August 28 - Mars Rock Rochette 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 August 28 Mars Rock Rochette Image Credit: NASA,JPL-Caltech Explanation: Taken on mission sol 180 (August 22) this sharp image from a HazardCamera on the Perseverance rover looks out across a rock strewn floorof Jezero crater on Mars.At 52.5 centimeters (21 inches) in diameter,one of the rover's steerable front wheels is at lower left in the frame.Near center is a largerock nicknamed Rochette.Mission planners don't want to avoid Rochette though.Instead Perseverance will be instructedto reach outwith its 2 meter long robotic arm andabrade the rock's surface,to determine whether it has a consistencysuitable for obtaining a sample, slightly thicker than a pencil,using the rover's coring bit.Samples collected by Perseverance would be returned toEarth by a future Mars mission. Tomorrow's picture: large rocks in space<| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| > Authors & editors: Robert Nemiroff(MTU) &Jerry Bonnell (UMCP)NASA Official: Phillip NewmanSpecific rights apply.NASA WebPrivacy Policy and Important NoticesA service of:ASD atNASA /GSFC& Michigan Tech. U.
APOD: 2021 August 27 - Elephant s Trunk and Caravan 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 August 27 Elephant's Trunk and Caravan Image Credit &Copyright:Robert Eder Explanation: Like an illustration in a galacticJust So Story, theElephant's Trunk Nebulawinds through the emission nebula and young star clustercomplex IC 1396, in the high and far offconstellationof Cepheus.Also known as vdB 142,seen on the left the cosmic elephant's trunk is over 20 light-years long.Removed by digital processing, novisible stars are in thisdetailed telescopic close-up view highlighting the bright swept-back ridgesthat outline pockets of coolinterstellardust and gas.But the dark,tendril-shaped clouds contain theraw material for star formation and hideprotostars within.Nearly 3,000light-yearsdistant, the relatively faint IC 1396 complexcovers a large region on the sky, spanning over 5 degrees.This starless renditionspans a 1 degree wide field of view though,about the angular size of 2 full moons.Of coursethe dark shapes below and right, marching toward the winding Elephant'sTrunk, are known to some as The Caravan. Tomorrow's picture: looking for a good rock<| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| > Authors & editors: Robert Nemiroff(MTU) &Jerry...
APOD: 2021 August 26 - A Blue Hour Full Moon 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 August 26 A Blue Hour Full Moon Image Credit &Copyright:Giorgia Hofer Explanation: Nature photographers and other fans of planet Earthalways look forward tothe bluehour.That's the transitionin twilight,just before sunrise or after sunset, whenthe Sun is below the horizon but land and sky are still suffused witha beautiful blue light.After sunset on August 21,this blue hour snapshot captured the nearly full Moon as itrose opposite the Sun, above the rugged Italian Alps fromCortina d'Ampezzo, Italy.Sharing bluish hues with the sky, the rocky pyramid of Monte Antelao,also known as the King of the Dolomites,is the region's prominent alpine peak.The moonlightis yellow, but even so this full Moon was known to someas a seasonal Blue Moon.That's because by one definitionthe third full Moon of a season with four full moonsin it is called a Blue Moon.Recognizing a season as the time between a solstice and an equinox,this season's fourthfull Moon will be risingin the blue hour of September 20, just before September's equinox. Tomorrow's picture: pixels in space<| Archive|...
APOD: 2021 August 25 - Solar System Ball Drop 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. Solar System Ball Drop Video Credit & Copyright: James O'Donoghue (JAXA) & Rami Mandow (Space Australia);Text: James O'Donoghue Explanation: Does a ball drop faster on Earth, Jupiter, or Uranus? The featured animation shows a ball dropping from one kilometer high toward the surfaces of famous solar system bodies, assuming no air resistance. The force of gravity depends on the mass of the attracting object, with higher masses pulling down with greater forces.But gravitational force also depends on distance from the center of gravity, with shorter distances causing the ball to drop faster. Combining both mass and distance, it might be surprising to see that Uranus pulls the ball down slightly slower than Earth, despite containing over 14 times more mass.This happens because Uranus has a much lower density, which puts its cloud tops further away from its center of mass. Although the falling ball always speeds up, if you were on the ball you would not feel this acceleration because you would be in free-fall.Of the three planets...
APOD: 2021 August 24 - PDS 70: Disk, Planets, and Moons 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 August 24 PDS 70: Disk, Planets, and Moons Image Credit: ALMA (ESO/NAOJ/NRAO); M. Benisty et al. Explanation: It's not the big disk that's attracting the most attention.Although the big planet-forming disk around the star PDS 70 is clearly imaged and itself quite interesting.It's also not the planet on the right, just inside the big disk, that’s being talked about the most. Although the planet PDS 70c is a newly formed and, interestingly, similar in size and mass to Jupiter.It's the fuzzy patch around the planet PDS 70c that's causing the commotion.That fuzzy patch is thought to be itself a dusty disk that is now forming into moons -- and that has never been seen before.The featured image was taken by the Atacama Large Millimeter Array (ALMA) of 66 radio telescopes in the high Atacama Desert of northern Chile. Based on ALMA data, astronomers infer that the moon-forming exoplanetary disk has a radius similar to our Earth's orbit, and may one day form three or so...
APOD: 2021 August 23 - Abell 3827: Cannibal Cluster Gravitational Lens 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 August 23 Abell 3827: Cannibal Cluster Gravitational Lens Image Credit: ESA/Hubble & NASA, R. Massey Explanation: Is that one galaxy or three?Toward the right of the featured Hubble image of the massive galaxy cluster Abell 3827 is what appears to be a most unusual galaxy -- curved and with three centers. A detailed analysis, however, finds that these are three images of the same background galaxy -- and that there are at least four more images. Light we see from the single background blue galaxy takes multiple paths through the complex gravity of the cluster, just like a single distant light can take multiple paths through the stem of a wine glass.Studying how clusters like Abell 3827 and their component galaxies deflect distant light gives information about how mass and dark matter are distributed.Abell 3827 is so distant, having a redshift of 0.1, that the light we see from it left about 1.3 billion years ago -- before dinosaurs roamed the Earth.Therefore, the cluster's central...