Astronomy Picture of the Day

🌌A Northern Winter Night Snow blankets the ground in this serene forest and sky view. Assembled in a 360 degree panoramic projection, the mosaicked frames were captured at January's end along a quiet country road near Siemiony, northeastern Poland, planet Earth. The night was cold and between trees reaching toward the sky shine the stars and nebulae of the northern winter Milky Way. Near zenith ...

🌌Apollo 14 Heads for Home Fifty years ago this Sunday (February 7, 1971), the crew of Apollo 14 left lunar orbit and headed for home. They watched this Earthrise from their command module Kittyhawk. With Earth's sunlit crescent just peeking over the lunar horizon, the cratered terrain in the foreground is along the lunar farside. Of course, while orbiting the Moon, the crew could watch Earth ris ...

🌌Apollo 14: A View from Antares Fifty years ago this Friday, Apollo 14's Lunar Module Antares landed on the Moon. Toward the end of the stay astronaut Ed Mitchell snapped a series of photos of the lunar surface while looking out a window, assembled into this detailed mosaic by Apollo Lunar Surface Journal editor Eric Jones. The view looks across the Fra Mauro highlands to the northwest of the la ...

🌌Found on the Moon: Candidate for Oldest Known Earth Rock Was the oldest known rock on Earth found on the Moon? Quite possibly. The story opens with the Apollo 14 lunar mission. Lunar sample 14321, a large rock found in Cone crater by astronaut Alan Shepard, when analyzed back on Earth, was found to have a fragment that was a much better match to Earth rocks than other Moon rocks. Even more surp ...

© Frank Kuszaj

🌌A Colorful Quadrantid Meteor Meteors can be colorful. While the human eye usually cannot discern many colors, cameras often can. Pictured is a Quadrantids meteor captured by camera over Missouri, USA, early this month that was not only impressively bright, but colorful. The radiant grit, likely cast off by asteroid 2003 EH1, blazed a path across Earth's atmosphere. Colors in meteors usually ori ...

© Göran Strand

🌌Lunar Halo over Snowy Trees Have you ever seen a halo around the Moon? This fairly common sight occurs when high thin clouds containing millions of tiny ice crystals cover much of the sky. Each ice crystal acts like a miniature lens. Because most of the crystals have a similar elongated hexagonal shape, light entering one crystal face and exiting through the opposing face refracts 22 degrees, w ...

🌌Asteroids in the Distance Rocks from space hit Earth every day. The larger the rock, though, the less often Earth is struck. Many kilograms of space dust pitter to Earth daily. Larger bits appear initially as a bright meteor. Baseball-sized rocks and ice-balls streak through our atmosphere daily, most evaporating quickly to nothing. Significant threats do exist for rocks near 100 meters in diam ...

© Ralf Rohner

🌌Southern Sky from 38,000 Feet Celestial sights of the southern sky shine above a cloudy planet Earth in this gorgeous night sky view. The scene was captured from an airliner's flight deck at 38,000 feet on a steady westbound ride to Lima, Peru. To produce the sharp airborne astrophotograph, the best of a series of short exposures were selected and digitally stacked. The broad band of the southe ...

© Liron Gertsman

🌌North American Nightscape On January 21, light from the Moon near first quarter illuminated the foreground in this snowy mountain and night scene. Known as The Lions, the striking pair of mountain peaks are north of Vancouver, British Colombia, Canada, North America, planet Earth. Poised above the twin summits, left of Deneb alpha star of the constellation Cygnus, are emission regions NGC 7000 ...

🌌Messier 66 Close Up Big, beautiful spiral galaxy Messier 66 lies a mere 35 million light-years away. The gorgeous island universe is about 100 thousand light-years across, similar in size to the Milky Way. This reprocessed Hubble Space Telescope close-up view spans a region about 30,000 light-years wide around the galactic core. It shows the galaxy's disk dramatically inclined to our line-of-si ...

🌌The Vertical Magnetic Field of NGC 5775 How far do magnetic fields extend up and out of spiral galaxies? For decades astronomers knew only that some spiral galaxies had magnetic fields. However, after NRAO's Very Large Array (VLA) radio telescope (popularized in the movie Contact) was upgraded in 2011, it was unexpectedly discovered that these fields could extend vertically away from the disk b ...

🌌Central NGC 1316: After Galaxies Collide How did this strange-looking galaxy form? Astronomers turn detectives when trying to figure out the cause of unusual jumbles of stars, gas, and dust like NGC 1316. Inspection indicates that NGC 1316 is an enormous elliptical galaxy that somehow includes dark dust lanes usually found in a spiral galaxy. Detailed images taken by the Hubble Space Telescope ...

© Tomáš Slovinský

🌌Southern Cross over Chilean Volcano Have you ever seen the Southern Cross? This famous four-star icon is best seen from Earth's Southern Hemisphere. The featured image was taken last month in Chile and captures the Southern Cross just to the left of erupting Villarrica, one of the most active volcanos in our Solar System. Connecting the reddest Southern Cross star Gacrux through the brightest s ...

© Roberto Colombari

🌌Massive Nearby Spiral Galaxy NGC 2841 It is one of the more massive galaxies known. A mere 46 million light-years distant, spiral galaxy NGC 2841 can be found in the northern constellation of Ursa Major. This sharp view of the gorgeous island universe shows off a striking yellow nucleus and galactic disk. Dust lanes, small, pink star-forming regions, and young blue star clusters are embedded in ...

🌌Recycling Cassiopeia A Massive stars in our Milky Way Galaxy live spectacular lives. Collapsing from vast cosmic clouds, their nuclear furnaces ignite and create heavy elements in their cores. After a few million years, the enriched material is blasted back into interstellar space where star formation can begin anew. The expanding debris cloud known as Cassiopeia A is an example of this final p ...

© Alvin Wu

🌌The Milky Ring An expanse of cosmic dust, stars and nebulae along the plane of our Milky Way galaxy form a beautiful ring in this projected all-sky view. The creative panorama covers the entire galaxy visible from planet Earth, an ambitious 360 degree mosaic that took two years to complete. Northern hemisphere sites in western China and southern hemisphere sites in New Zealand were used to coll ...

© Wes Higgins

🌌M78 Wide Field Interstellar dust clouds and glowing nebulae abound in the fertile constellation of Orion. One of the brightest, M78, is centered in this colorful, wide field view, covering an area north of Orion's belt. At a distance of about 1,500 light-years, the bluish reflection nebula is around 5 light-years across. Its tint is due to dust preferentially reflecting the blue light of hot, y ...

🌌The Magnetic Field of the Whirlpool Galaxy Do magnetic fields always flow along spiral arms? Our face-on view of the Whirlpool Galaxy (M51) allows a spectacularly clear view of the spiral wave pattern in a disk-shaped galaxy. When observed with a radio telescope, the magnetic field appears to trace the arms' curvature. However, with NASA’s flying Stratospheric Observatory for Infrared Astronomy ...

© Alessandra Masi

🌌A Lunar Corona with Jupiter and Saturn Why does a cloudy moon sometimes appear colorful? The effect, called a lunar corona, is created by the quantum mechanical diffraction of light around individual, similarly-sized water droplets in an intervening but mostly-transparent cloud. Since light of different colors has different wavelengths, each color diffracts differently. Lunar Coronae are one of ...

© Russell Croman

🌌The Medulla Nebula Supernova Remnant What powers this unusual nebula? CTB-1 is the expanding gas shell that was left when a massive star toward the constellation of Cassiopeia exploded about 10,000 years ago. The star likely detonated when it ran out of elements, near its core, that could create stabilizing pressure with nuclear fusion. The resulting supernova remnant, nicknamed the Medulla Neb ...

🌌Jets from Unusual Galaxy Centaurus A The jets emanating from Centaurus A are over a million light years long. These jets of streaming plasma, expelled by a giant black hole in the center of this spiral galaxy, light up this composite image of Cen A. Exactly how the central black hole expels infalling matter remains unknown. After clearing the galaxy, however, the jets inflate large radio bubble ...

🌌The Mountains of NGC 2174 This fantastic skyscape lies near the edge of NGC 2174 a star forming region about 6,400 light-years away in the nebula-rich constellation of Orion. It follows mountainous clouds of gas and dust carved by winds and radiation from the region's newborn stars, now found scattered in open star clusters embedded around the center of NGC 2174, off the top of the frame. Thoug ...

🌌A Plutonian Landscape This shadowy landscape of majestic mountains and icy plains stretches toward the horizon on a small, distant world. It was captured from a range of about 18,000 kilometers when New Horizons looked back toward Pluto, 15 minutes after the spacecraft's closest approach on July 14. The dramatic, low-angle, near-twilight scene follows rugged mountains formally known as Norgay M ...

🌌Aurora Slathers Up the Sky Like salsa verde on your favorite burrito, a green aurora slathers up the sky in this 2017 June 25 snapshot from the International Space Station. About 400 kilometers (250 miles) above Earth, the orbiting station is itself within the upper realm of the auroral displays. Aurorae have the signature colors of excited molecules and atoms at the low densities found at extr ...

© Giulio Cobianchi

🌌Arches Across an Arctic Sky What are these two giant arches across the sky? Perhaps the more familiar one, on the left, is the central band of our Milky Way Galaxy. This grand disk of stars and nebulas here appears to encircle much of the southern sky. Visible below the stellar arch is the rusty-orange planet Mars and the extended Andromeda galaxy. For a few minutes during this cold artic night ...

© Rodrigo Guerra

🌌A Historic Brazilian Constellation The night sky is filled with stories. Cultures throughout history have projected some of their most enduring legends onto the stars above. Generations of people see these stellar constellations, hear the associated stories, and pass them down. Featured here is the perhaps unfamiliar constellation of the Old Man, long recognized by the Tupi peoples native to re ...