Astronomic Picture of Day

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elraro #91 Abr '16

Heliopause Electrostatic Rapid Transit System

Want to take a fast trip to the edge of the Solar System? Consider a ride on a Heliopause Electrostatic Rapid Transit System (HERTS). The concept is currently being tested and it might take only 10 to 15 years to make the trip of over 100 Astronomical Units (15 billion kilometers). That's fast compared to the 35 years it took Voyager 1, presently humanity's most distant spacecraft, to approach the heliopause or outer boundary of the influence of the solar wind. HERTS would use an advanced electric solar sail that works by extending multiple, 20 kilometer or so long, 1 millimeter thin, positively charged wires from a rotating spacecraft. The electrostatic force generated repels fast moving solar wind protons to create thrust. Compared to a reflective solar light sail, another propellantless deep space propulsion system, the electric solar wind sail could continue to accelerate at greater distances from the Sun, still developing thrust as it cruised toward the outer planets.

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elraro #92 Abr '16

Asperatus Clouds Over New Zealand

What kind of clouds are these? Although their cause is presently unknown, such unusual atmospheric structures, as menacing as they might seem, do not appear to be harbingers of meteorological doom. Known informally as Undulatus asperatus clouds, they can be stunning in appearance, unusual in occurrence, are relatively unstudied, and have even been suggested as a new type of cloud. Whereas most low cloud decks are flat bottomed, asperatus clouds appear to have significant vertical structure underneath. Speculation therefore holds that asperatus clouds might be related to lenticular clouds that form near mountains, or mammatus clouds associated with thunderstorms, or perhaps a foehn wind -- a type of dry downward wind that flows off mountains. Such a wind called the Canterbury arch streams toward the east coast of New Zealand's South Island. The featured image, taken above Hanmer Springs in Canterbury, New Zealand, in 2005, shows great detail partly because sunlight illuminates the undulating clouds from the side. Follow APOD on: Facebook, Google Plus, Instagram, or Twitter

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Panch #93 Abr '16

#92 Preciosa ! Aunque salgo de casa, veo eso y me bajo al sótano con víveres jajaja

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elraro #94 Abr '16

The International Space Station over Earth

The International Space Station is the largest object ever constructed by humans in space. The station perimeter extends over roughly the area of a football field, although only a small fraction of this is composed of modules habitable by humans. The station is so large that it could not be launched all at once -- it continues to be built built piecemeal. To function, the ISS needs huge trusses, some over 15 meters long and with masses over 10,000 kilograms, to keep it rigid and to route electricity and liquid coolants. Pictured above, the immense space station was photographed from the now-retired space shuttle Atlantis after a week-long stay in 2010. Across the image top hangs part of a bright blue Earth, in stark contrast to the darkness of interstellar space across the bottom.

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elraro #95 Abr '16

Andromeda Rising over Colombia

What’s that rising over the hill? A galaxy. Never having seen a galaxy themselves, three friends of an industrious astrophotographer experienced an exhilarating night sky firsthand that featured not only the band of our Milky Way galaxy but also Milky Way's neighbor -- the Andromeda galaxy. Capturing the scene required careful pre-shot planning including finding a good site, waiting for good weather, balancing relative angular sizes with a zoom lens, managing ground lighting, and minimizing atmospheric light absorption. The calculated shot therefore placed the friends on a hill about 250 meters away and about 50 meters up. The featured single-exposure image was taken last July 26 at about 11:30 pm in Guatape, Colombia, about two hours from Medellin. The surrounding stars visible are all nearby in our own galaxy, while the small galaxy just above M31 is Andromeda's satellite M110. Press Alert: Communicating Astronomy meeting to be held in Colombia in May

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elraro #96 Abr '16

Galaxy Einstein Ring

Can one galaxy hide behind another? Not in the case of SDP.81. Here the foreground galaxy, shown in blue in an image taken by the Hubble Space Telescope, acts like a huge gravitational lens, pulling light from a background galaxy, shown in red in an image taken in radio waves by the Atacama Large Millimeter Array (ALMA), around it, keeping it visible. The alignment is so precise that the distant galaxy is distorted into part of a ring around the foreground galaxy, a formation known as an Einstein ring. Detailed analysis of the gravitational lens distortions indicate that a small dark satellite galaxy participates in the deflections, bolstering indication that many satellite galaxies are quite dim and dominated by dark matter. That small galaxy is depicted by a small white dot on the left. Although spanning only a few arcseconds, the featured Einstein ring is really tens of thousands of light years across. Comments, questions? Just click the Discuss link two lines below.

hamai #97 Abr '16 :psyduck:

Sigue con el trabajo, es todo muy interesante

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elraro #98 Abr '16

The Comet, the Owl, and the Galaxy

Comet C/2014 S2 (PanSTARRS) poses for a Messier moment in this telescopic snapshot from April 18. In fact it shares the 1.5 degree wide field-of-view with two well-known entries in the 18th century comet-hunting astronomer's famous catalog. Outward bound and sweeping through northern skies just below the Big Dipper, the fading visitor to the inner Solar System was about 18 light-minutes from our fair planet. Dusty, edge-on spiral galaxy Messier 108 (upper right) is more like 45 million light-years away. A planetary nebula with an aging but intensely hot central star, the owlish Messier 97 is only about 12 thousand light-years distant though, still well within our own Milky Way galaxy. Astronomers expect the orbit of this comet PanSTARRS to return it to the inner Solar System around the year 4226.

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elraro #99 Abr '16

NGC 7635: The Bubble Nebula

Blown by the wind from a massive star, this interstellar apparition has a surprisingly familiar shape. Cataloged as NGC 7635, it is also known simply as The Bubble Nebula. Although it looks delicate, the 7 light-year diameter bubble offers evidence of violent processes at work. Above and left of the Bubble's center is a hot, O-type star, several hundred thousand times more luminous and around 45 times more massive than the Sun. A fierce stellar wind and intense radiation from that star has blasted out the structure of glowing gas against denser material in a surrounding molecular cloud. The intriguing Bubble Nebula and associated cloud complex lie a mere 7,100 light-years away toward the boastful constellation Cassiopeia. This sharp, tantalizing view of the cosmic bubble is a composite of Hubble Space Telescope image data from 2016, released to celebrate the 26th anniversary of Hubble's launch. Celebrate: Planet Earth Day

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elraro #100 Abr '16

Milky Way in Moonlight

A waning crescent moon, early morning twilight, and Al Hamra's city lights on the horizon can't hide the central Milky Way in this skyscape from planet Earth. Captured in a single exposure, the dreamlike scene looks southward across the region's grand canyon from Jabal Shams (Sun Mountain), near the highest peak in Oman, on the Arabian Peninsula. Mist, moonlight, and shadows still play along the steep canyon walls. Dark rifts along the luminous band of the Milky Way are the galaxy's cosmic dust clouds. Typically hundreds of light-years distant, they obscure starlight along the galactic plane, viewed edge-on from the Solar System's perspective.

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elraro #101 Abr '16

M16: Pillars of Star Creation

En la nebulosa del Águila se están formando estrellas. Esta fotografía, tomada por el Telescopio Espacial Hubble en 1995, muestra glóbulos gaseosos evaporándose y emergiendo de los pilares de gas hidrógeno molecular y de polvo. Los pilares gigantes tienen años luz de largo. Son tan densos que el gas del interior se contrae gravitacionalmente y engendra estrellas. Al final de cada uno de los pilares, la intensa radiación procedente de las estrellas jóvenes hace hervir el material de baja densidad y deja expuestos viveros estelares con densos glóbulos gaseosos evaporándose. La nebulosa del Águila, asociada con el cúmulo estelar abierto M16, se encuentra a unos 7.000 años luz de distancia. Los pilares de la creación fueron fotografiados de nuevo en 2007 por el Telescopio Espacial Spitzer en luz infrarroja. Estas fotografías hacen pensar que los pilares ya han sido destruidos por una supernova local, pero la luz de este evento aún no ha llegado a la Tierra.

spoiler

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elraro #102 Abr '16

Supernova Remnant Simeis 147: The Spaghetti Nebula

It's easy to get lost following the intricate strands of the Spaghetti Nebula. A supernova remnant cataloged as Simeis 147 and Sh2-240, the glowing gas filaments cover nearly 3 degrees -- 6 full moons -- on the sky. That's about 150 light-years at the stellar debris cloud's estimated distance of 3,000 light-years. This sharp composite includes image data taken through a narrow-band filter to highlight emission from hydrogen atoms tracing the shocked, glowing gas. The supernova remnant has an estimated age of about 40,000 years, meaning light from the massive stellar explosion first reached Earth about 40,000 years ago. But the expanding remnant is not the only aftermath. The cosmic catastrophe also left behind a spinning neutron star or pulsar, all that remains of the original star's core.

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elraro #103 Abr '16

NGC 6872: A Stretched Spiral Galaxy

What makes this spiral galaxy so long? Measuring over 700,000 light years across from top to bottom, NGC 6872, also known as the Condor galaxy, is one of the most elongated barred spiral galaxies known. The galaxy's protracted shape likely results from its continuing collision with the smaller galaxy IC 4970, visible just above center. Of particular interest is NGC 6872's spiral arm on the upper left, as pictured here, which exhibits an unusually high amount of blue star forming regions. The light we see today left these colliding giants before the days of the dinosaurs, about 300 million years ago. NGC 6872 is visible with a small telescope toward the constellation of the Peacock (Pavo).

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elraro #104 Abr '16

Omega Centauri: The Brightest Globular Star Cluster

This huge ball of stars predates our Sun. Long before humankind evolved, before dinosaurs roamed, and even before our Earth existed, ancient globs of stars condensed and orbited a young Milky Way Galaxy. Of the 200 or so globular clusters that survive today, Omega Centauri is the largest, containing over ten million stars. Omega Centauri is also the brightest globular cluster, at apparent visual magnitude 3.9 it is visible to southern observers with the unaided eye. Cataloged as NGC 5139, Omega Centauri is about 18,000 light-years away and 150 light-years in diameter. Unlike many other globular clusters, the stars in Omega Centauri show several different ages and trace chemical abundances, indicating that the globular star cluster has a complex history over its 12 billion year age.

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elraro #105 Abr '16

A Dust Angel Nebula

The combined light of stars along the Milky Way are reflected by these cosmic dust clouds that soar some 300 light-years or so above the plane of our galaxy. Dubbed the Angel Nebula, the faint apparition is part of an expansive complex of dim and relatively unexplored, diffuse molecular clouds. Commonly found at high galactic latitudes, the dusty galactic cirrus can be traced over large regions toward the North and South Galactic poles. Along with the refection of starlight, studies indicate the dust clouds produce a faint reddish luminescence, as interstellar dust grains convert invisible ultraviolet radiation to visible red light. Also capturing nearby Milky Way stars and an array of distant background galaxies, the deep, wide-field 3x5 degree image spans about 10 Full Moons across planet Earth's sky toward the constellation Ursa Major.

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elraro #106 Abr '16

Fermi's Gamma-ray Moon

If you could only see gamma-rays, photons with up to a billion or more times the energy of visible light, the Moon would be brighter than the Sun! That startling notion underlies this novel image of the Moon, based on data collected by the Fermi Gamma-ray Space Telescope's Large Area Telescope (LAT) instrument during its first seven years of operation (2008-2015). Fermi's gamma-ray vision doesn't distinguish details on the lunar surface, but a gamma-ray glow consistent with the Moon's size and position is clearly found at the center of the false color map. The brightest pixels correspond to the most significant detections of lunar gamma-rays. Why is the gamma-ray Moon so bright? High-energy charged particles streaming through the Solar System known as cosmic rays constantly bombard the lunar surface, unprotected by a magnetic field, generating the gamma-ray glow. Because the cosmic rays come from all sides, the gamma-ray Moon is always full and does not go through phases. The first gamma-ray image of the Moon was captured by the EGRET instrument onboard the Compton Gamma-ray Observatory, launched 25 years ago.

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elraro #107 Abr '16

Moon over Makemake

Makemake, second brightest dwarf planet of the Kuiper belt, has a moon. Nicknamed MK2, Makemake's moon reflects sunlight with a charcoal-dark surface, about 1,300 times fainter than its parent body. Still, it was spotted in Hubble Space Telescope observations intended to search for faint companions with the same technique used to find the small satellites of Pluto. Just as for Pluto and its satellites, further observations of Makemake and orbiting moon will measure the system's mass and density and allow a broader understanding of the distant worlds. About 160 kilometers (100 miles) across compared to Makemake's 1,400 kilometer diameter, MK2's relative size and contrast are shown in this artist's vision. An imagined scene of an unexplored frontier of the Solar System, it looks back from a spacecraft's vantage as the dim Sun shines along the Milky Way. Of course, the Sun is over 50 times farther from Makemake than it is from planet Earth.

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elraro #108 May '16

Contemplating the Sun

Have you contemplated your home star recently? Featured here, a Sun partially eclipsed on the top left by the Moon is also seen eclipsed by earthlings contemplating the eclipse below. The spectacular menagerie of silhouettes was taken in 2012 from the Glen Canyon National Recreation Area near Page, Arizona, USA, where park rangers and astronomers expounded on the unusual event to interested gatherers. Also faintly visible on the Sun's disk, just to the lower right of the dark Moon's disk, is a group of sunspots. Although a partial solar eclipse by the Moon is indeed a good chance to contemplate the Sun, a great chance -- and one that is significantly more rare -- will occur next week when the Sun undergoes a partial eclipse by the planet Mercury.

Tokito #109 May '16

Qué bonito! Sería bueno si alguien pudiera traducir algunos textos, pero bien traducidos y no con el traductor de Google o similares xD

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[Borrado] #110 May '16

#109 En teoria, hace un par de semanas se comento y ya dijo que los textos si estan traducidos, pero que tenia que modificar el bot. Claro, que tambien puede que fuese un bait xD

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elraro #111 May '16

#110 no es bait, pero estoy de exámenes, hasta que acabe nada, sry

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[Borrado] #112 May '16

#111 No pasa nada. Yo es que de bots para MV no entiendo y baraje esa posibilidad xD

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elraro #113 May '16

Crossing Mars

Where is NASA's rover Curiosity going on Mars? Its geographical goals are on the slopes of Mount Sharp, whose peak is seen in the background on the right. A key scientific goal, however, remains to better assess when and where conditions on Mars were once suitable for life, in particular microbial life. To further this goal, Curiosity was directed to cross the rugged terrain of Nautkluft Plateau, visible in the featured image on the foreground left. Curiosity is crossing toward smoother uphill sites with rocks containing hematite and sulfates, sites that could give the rolling rover new clues on how long this part of Mars was wet -- and hence more favorable for life -- before drying out. Of recent concern, however, is Curiosity's aluminum wheels, which are showing increasing signs of wear. Although already fulfilling the goals of its two year study, Curiosity's mission has been extended as it continues to uncover valuable information about the extraordinary past of Mars, the next planet out from the Sun from Earth.

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elraro #114 May '16

Aurora over Sweden

It was bright and green and stretched across the sky. This striking aurora display was captured last month just outside of Östersund, Sweden. Six photographic fields were merged to create the featured panorama spanning almost 180 degrees. Particularly striking aspects of this aurora include its sweeping arc-like shape and its stark definition. Lake Storsjön is seen in the foreground, while several familiar constellations and the star Polaris are visible through the aurora, far in the background. Coincidently, the aurora appears to avoid the Moon visible on the lower left. The aurora appeared a day after a large hole opened in the Sun's corona allowing particularly energetic particles to flow out into the Solar System. The green color of the aurora is caused by oxygen atoms recombining with ambient electrons high in the Earth's atmosphere.

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elraro #115 May '16

A Mercury Transit Sequence

This coming Monday, Mercury will cross the face of the Sun, as seen from Earth. Called a transit, the last time this happened was in 2006. Because the plane of Mercury's orbit is not exactly coincident with the plane of Earth's orbit, Mercury usually appears to pass over or under the Sun. The above time-lapse sequence, superimposed on a single frame, was taken from a balcony in Belgium shows the entire transit of 2003 May 7. The solar crossing lasted over five hours, so that the above 23 images were taken roughly 15 minutes apart. The north pole of the Sun, the Earth's orbit, and Mercury's orbit, although all different, all occur in directions slightly above the left of the image. Near the center and on the far right, sunspots are visible. After Monday, the next transit of Mercury will occur in 2019. NASA Coverage: 2016 May 9 Mercury Transit of the Sun

Tokito #116 May '16

#113 ¿Por qué la NASA censura partes de sus imágenes? En esa misma imagen por ejemplo. Ya no se si será por no enseñar sus aparatos por si les copian, o porque no quieren enseñar algo por otra razón.

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Chupachota #117 May '16 Penitente

#116 Qué ves censurado en esa imagen???

Tokito #118 May '16

#116 Yo creo que está claro. La parte que han tapado con color negro.

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J_Penny #119 May '16

#118 No creo que este censurado, serán múltiples exposiciones(fotos) necesarias para hacer la panorámica con esa resolucion

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elraro #120 May '16

The SONG and the Hunter

Near first quarter, the Moon in March lights this snowy, rugged landscape, a view across the top of Tenerife toward La Palma in the Canary Islands Spanish archipelago. The large Teide volcano, the highest point in Spain, looms over the horizon. Shining above are familiar bright stars of Orion, the Hunter. Adding to the dreamlike scene is the 1 meter diameter prototype telescope of the global network project called the Stellar Observations Network Group or SONG. The SONG's fully robotic observatory was captured during the 30 second exposure while the observatory dome, with slit open, was rotated across the field of view.

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