APOD: 2022 February 19 - Peculiar Galaxies of Arp 273 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 February 19 Peculiar Galaxies of Arp 273 Image Credit &Copyright: Jason Guenzel Explanation: The spiky starsin the foreground of this backyardtelescopic frame are well within our ownMilky Way Galaxy.But the two eye-catching galaxies lie far beyond the Milky Way,at a distance of over 300 million light-years.Their distorted appearance is due to gravitational tidesas the pair engage in close encounters.Cataloged as Arp 273 (also asUGC 1810), the galaxies do lookpeculiar,but interacting galaxies are now understood to becommon in the universe.Nearby, the large spiral Andromeda Galaxy is known to besome 2 million light-years away and approaching the Milky Way.The peculiar galaxies of Arp 273 may offer an analog of theirfar future encounter.Repeated galaxy encounters on acosmic timescale can ultimatelyresult in a merger into a single galaxy of stars.From our perspective, the bright cores of the Arp 273 galaxies areseparated by only a little over 100,000 light-years. Tomorrow's picture: aurora over white dome <| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss| > Authors & editors:...
APOD: 2022 February 18 - Three Clusters in Puppis 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 February 18 Three Clusters in Puppis Image Credit &Copyright: Dave Doctor Explanation: Galactic oropen star clustersare young.The swarms of stars are born together near the plane of the Milky Way,but their numberssteadily dwindleas cluster members areejected by galactic tides and gravitational interactions.Caught inthis telescopic frameover three degrees across are threegood examples of galactic star clusters,seen toward the southern sky's nautical constellationPuppis.Below and left, M46 issome 5,500 light-years in the distance.Right of centerM47 isonly 1,600 light-years away andNGC 2423 (top) is about 2500 light-years distant.Around 300 million years young M46contains a few hundred stars in a region about 30 light-yearsacross.Sharp eyes can spot a planetary nebula,NGC 2438,at about 11 o'clock against the M46 cluster stars.But that nebula'scentral staris billions of years old, andNGC 2438 is likely a foreground object only by chancealong the line of sight to youthful M46.Even younger, aged around 80 million years, M47 is asmaller and looser star cluster spanning about 10 light-years.Star cluster NGC 2423 is pushing about 750 million yearsin age though.NGC 2423...
APOD: 2022 February 16 - Eiffel Tower Prominence on the Sun 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. Eiffel Tower Prominence on the Sun Video Credit & Copyright: Hawk Wolinski Explanation: What's that on the Sun?Although it may look like a flowing version of the Eiffel Tower, it is a solar prominence that is actually much bigger -- about the height of Jupiter.The huge prominence emerged about ten days ago, hovered over the Sun's surface for about two days, and then erupted -- throwing a coronal mass ejection (CME) into the Solar System.The featured video, captured from the astrophotographer's backyard in Hendersonville, Tennessee, USA, shows an hour time-lapse played both forwards and backwards.That CME did not impact the Earth, but our Sun had unleashed other recent CMEs that not only triggered Earthly auroras, but puffed out the Earth's atmosphere enough to cause just-launched Starlink satellites to fall back.Activity on the Sun, including sunspots, prominences, CMEs and flares, continues to increase as the Sun evolves away from a deep minimum in its 11-year magnetic cycle. Birthday Surprise: What picture did APOD feature on your birthday?...
APOD: 2022 February 15 - Terminator 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. 2022 February 15 Terminator Moon Image Credit: NASA, Lunar Reconnaissance Orbiter, SVS; Processing & Copyright: Jai & Neil Shet Explanation: What's different about this Moon?It's the terminators.In the featured image, you can't directly see any terminator -- the line that divides the light of day from the dark of night.That's because the image is a digital composite of 29 near-terminator lunar strips. Terminator regions show the longest and most prominent shadows -- shadows which, by their contrast and length, allow a flat photograph to appear three-dimensional.The original images and data were taken near the Moon by NASA's Lunar Reconnaissance Orbiter. Many of the Moon's craters stand out because of the shadows they all cast to the right.The image shows in graphic detail that the darker regions known as maria are not just darker than the rest of the Moon -- they are flatter. Dial-A-Moon: Find the phase of the Moon on your birthday. Tomorrow's picture: eroding sun tower <| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD| Discuss|...
APOD: 2022 February 14 - In the Heart of the Heart 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. 2022 February 14 In the Heart of the Heart Nebula Image Credit & Copyright: Adam Jensen Explanation: What excites the Heart Nebula?First, the large emission nebula dubbedIC 1805 looks, in whole, like a human heart. Its shape perhaps fitting of the Valentine's Day, this heart glows brightly in red lightemitted by its most prominent element: excited hydrogen. The red glow and the larger shape are all created by asmall group of stars near thenebula's center. In the heart of the Heart Nebula are young stars from the open star cluster Melotte 15 that are eroding away several picturesque dust pillars with their energetic light and winds.The open cluster of stars contains a fewbright stars nearly 50 times the mass of our Sun,many dim stars only a fraction of the mass of our Sun, and anabsent microquasarthat was expelled millions of years ago. The Heart Nebula is located about 7,500 light years away toward theconstellation of the mythological Queen of Aethiopia (Cassiopeia). Tomorrow's picture: terminator moon...
APOD: 2022 February 13 - Earth at Night 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 February 13 Earth at Night Image Credit: NASA, Suomi NPP VIIRS; Data: Miguel Román (NASA GSFC); Processing: Joshua Stevens Explanation: This is what the Earth looks like at night. Can you find your favorite country or city? Surprisingly, city lights make this task quite possible. Human-made lights highlight particularly developed or populated areas of the Earth's surface, including the seaboards of Europe, the eastern United States, and Japan. Many large cities are located near rivers or oceans so that they can exchange goods cheaply by boat. Particularly dark areas include the central parts of South America, Africa, Asia, and Australia.The featured image, nicknamed Black Marble, is actually a composite of hundreds of pictures remade in 2016 from data taken by the orbiting Suomi NPP satellite. Tomorrow's picture: space for the heart <| 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....
APOD: 2022 February 12 - Aurora by Moonlight 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 February 12 Aurora by Moonlight Image Credit &Copyright: P-M Hedén(Clear Skies,TWAN) Explanation: The icewas singingas light from a bright gibbous Moon cast shadows across thisfrozen lake,about 20 kilometers north of Stockholm, Sweden, planet Earth.In the alluring night skyscape captured onFebruary 10,shimmering auroral curtains of light dance in the evening sky.On that northern night nature's performance includedthe auroral displays fostered by a minor geomagnetic storm.Stormy space weatherwas the result of acoronal mass ejection, erupting from a solar prominence daysearlier and brushing our fair planet's magnetosphere. Tomorrow's picture: planet in the dark <| 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: 2022 February 11 - IC 342: The Hidden Galaxy in Camelopardalis 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 February 11 IC 342: The Hidden Galaxy in Camelopardalis Image Credit &Copyright: Daniel Feller Explanation: Similarin size to large, bright spiral galaxies in our neighborhood,IC 342is a mere 10 million light-yearsdistant in the long-necked,northern constellation Camelopardalis.A sprawling island universe,IC 342 would otherwise be a prominent galaxy in our night sky,but it is hidden from clear view and onlyglimpsed through the veil of stars, gas and dust cloudsalong the plane of our own Milky Way galaxy.Even though IC 342's light is dimmed and reddened by interveningcosmic clouds,thissharptelescopic image traces the galaxy's own obscuring dust,young star clusters, and glowing pink star forming regions along spiralarms that wind far fromthe galaxy'score.IC 342 may have undergone a recent burst ofstar formation activity and isclose enough to have gravitationallyinfluenced the evolution of thelocal groupof galaxies and the Milky Way. Tomorrow's picture: northern 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...
APOD: 2022 February 10 - T Tauri and Hind's Variable 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. 2022 February 10 T Tauri and Hind's Variable Nebula Image Credit &Copyright: Dawn Lowry,Gian Lorenzo Ferretti, Ewa Pasiak and Terry Felty Explanation: The star with an orange tint near top center in this dustytelescopic frameis T Tauri, prototype of the class of T Tauri variable stars. Next to it (right) is a yellow cosmic cloudhistoricallyknown as Hind's Variable Nebula (NGC 1555).About 650 light-years away,at the boundaryof thelocal bubbleand the Taurus molecular cloud, both star and nebulaare seen to vary significantly in brightnessbut not necessarily at the same time,adding to the mystery of the intriguing region.T Tauri stars are now generallyrecognizedas young (less than a few million years old), sun-like stars still in theearlystages of formation.To furthercomplicate the picture, infrared observations indicatethat T Tauri itself is part of a multiple system andsuggest that the associatedHind'sNebula may also contain a very young stellar object.The well-composed image spans about 8 light-years at the estimateddistance of T Tauri. Tomorrow's picture: pixels in space <| Archive| Submissions | Index| Search| Calendar|...
APOD: 2022 February 9 - Eta Car: 3D Model of the Most Dangerous Star Known 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. Eta Car: 3D Model of the Most Dangerous Star Known Video Credit: NASA, CXC, April Hobart; Text: Michael F. Corcoran (NASA, Catholic U., HEAPOW) Explanation: What's the most dangerous star near earth? Many believe it's Eta Carinae, a binary star system about 100 times the mass of the Sun, just 10,000 light years from earth. Eta Carinae is a ticking time bomb, set to explode as a supernova in only a few million years, when it may bathe the earth in dangerous gamma rays. The star suffered a notorious outburst in the 1840s when it became the brightest star in the southern sky, only to fade to obscurity within decades. The star was not destroyed, but lies hidden behind a thick, expanding, double-lobed structure called the Homunculus which now surrounds the binary. Studies of this ejecta provide forensic clues about the explosion. Using observations from NASA satellites we can now visualize the 3D distribution of the shrapnel, all the way from the...
APOD: 2022 February 8 - Aurora and Light Pillars over Norway 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 February 8 Aurora and Light Pillars over Norway Image Credit & Copyright: Alexandre Correia Explanation: Which half of this sky is your favorite?On the left, the night sky is lit up by particles expelled from the Sun that later collided with Earth's upper atmosphere — creating bright auroras. On the right, the night glows with ground lights reflected by millions of tiny ice crystals falling from the sky — creating light pillars. And in the center, the astrophotographer presents your choices.The light pillars are vertical columns because the fluttering ice-crystals are mostly flat to the ground, and their colors are those of the ground lights.The auroras cover the sky and ground in the green hue of glowing oxygen, while their transparency is clear because you can see stars right through them.Distant stars dot the background, including bright stars from the iconic constellation of Orion. The featured image was captured in a single exposure two months ago near Kautokeino, Norway. Favorite sky half: Left half (aurora)...
APOD: 2022 February 7 - NGC 4651: The Umbrella 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. 2022 February 7 NGC 4651: The Umbrella Galaxy Image Credit & Copyright: CFHT, Coelum, MegaCam, J.-C. Cuillandre (CFHT) & G. A. Anselmi (Coelum) Explanation: It's raining stars. What appears to be a giant cosmic umbrella is now known to be a tidal stream of stars stripped from a small satellite galaxy.The main galaxy, spiral galaxy NGC 4651, is about the size of our Milky Way, while its stellar parasol appears to extendsome 100 thousand light-years above this galaxy's bright disk.A small galaxy was likely torn apart by repeated encounters asit swept back and forth on eccentric orbits through NGC 4651.The remaining stars will surely fall back and become part of a combined larger galaxy over the next few million years.The featured image was captured by the Canada-France-Hawaii Telescope (CFHT) in Hawaii, USA. The Umbrella Galaxy lies about 50 million light-years distant toward the well-groomed northern constellationComaBerenices. Almost Hyperspace: Random APOD Generator Tomorrow's picture: vote the sky <| Archive| Submissions | Index| Search| Calendar| RSS| Education| About APOD|...
APOD: 2022 February 6 - Blue Marble 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. 2022 February 6 Blue Marble Earth Image Credit: NASA, Apollo 17 Crew Explanation: Welcome to planet Earth, the third planet from a star named the Sun. The Earth is shaped like a sphere and composed mostly of rock. Over 70 percent of the Earth's surface is water. The planet has a relatively thin atmosphere composed mostly of nitrogen and oxygen. The featured picture of Earth, dubbed The Blue Marble, was taken from Apollo 17 in 1972 and features Africa and Antarctica. It is thought to be one of the most widely distributed photographs of any kind. Earth has a single large Moon that is about 1/4 of its diameter and, from the planet's surface, is seen to have almost exactly the same angular size as the Sun. With its abundance of liquid water, Earth supports a large variety of life forms, including potentially intelligent species such as dolphins and humans. Please enjoy your stay on planet Earth. Tomorrow's picture: galactic rain <| Archive| Submissions | Index| Search| Calendar| RSS|...
APOD: 2022 February 5 - Symbiotic R Aquarii 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 February 5 Symbiotic R Aquarii Image Credit: X-ray: NASA/CXC/SAO/R. Montez et al.; Optical: Data: NASA/ESA/STScI, Processing: Judy Schmidt (CC BY-NC-SA) Explanation: Variable star R Aquariiis actually an interacting binary star system, two stars thatseem to have a close symbiotic relationship.Centered in thisspace-based optical/x-raycomposite image it lies about 710 light years away.The intriguing system consists of a cool red giant starand hot, densewhite dwarf starin mutual orbit around their common center of mass.With binoculars you can watch as R Aquariisteadily changes its brightness over the course of a year or so.The binary system's visible light is dominated by the red giant,itself a Mira-type long period variable star.But material in the cool giant star's extended envelopeis pulled by gravityonto the surface of the smaller, denser white dwarf,eventually triggeringa thermonuclear explosion, blasting material into space.Astronomers have seen such outbursts over recent decades.Evidence for much older outbursts is seen inthese spectacular structuresspanning almost a light-year asobserved by the Hubble Space Telescope (in red and blue).Data from the Chandra X-ray Observatory (in purple)...