| Piú viste - The Universe Inside |
WarmPlanetColdStar-PIA11980.jpgWarm Planet, Cold Star63 visiteThis artist's conception shows a young, hypothetical planet around a cool star. A soupy mix of potentially life-forming chemicals can be seen pooling around the base of the jagged rocks. Observations from NASA's Spitzer Space Telescope hint that planets around cool stars — the so-called M-dwarfs and Brown dwarfs that are widespread throughout our Galaxy — might possess a different mix of life-forming, or prebiotic, chemicals than our young Earth.
Life on our Planet is thought to have arisen out of a pond-scum-like mix of chemicals. Some of these chemicals are thought to have come from a planet-forming disk of gas and dust that swirled around our young Sun. Meteorites carrying the chemicals might have crash-landed on Earth.
Astronomers don't know if these same life-generating processes are taking place around stars that are cooler than our Sun, but the Spitzer observations show their disk chemistry is different. Spitzer detected a prebiotic molecule, called Hydrogen Cyanide (Cianuro di Idrogeno), in the disks around yellow stars like our Sun, but found none around cooler, less massive, reddish stars. Hydrogen Cyanide is a carbon-containing, or organic compound. Five Hydrogen Cyanide molecules can join up to make Adenine — a chemical element of the DNA molecule found in all living organisms on Earth.MareKromium
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Terra_04.jpgTerra! (additional process. by Giorgio Picciau)63 visitenessun commentoMareKromium
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Triton.jpgLord of the Abyss (by Roberto Tremolada)63 visitenessun commentoMareKromium
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Vision.jpgGalactic Vision63 visitenessun commentoMareKromium
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Sun-Halo.jpg...E Finchè 'l Sole splenderà...63 visitenessun commentoMareKromium
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Sun Halo-2.jpgBright Sun, Dark Sky62 visiteCaption originale:"Have you ever seen a halo around the Sun? 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, which corresponds to the radius of the Sun Halo. A similar Moon Halo may be visible during the night. The picture was taken in Gunlock, Utah, USA. A flock of birds was caught by chance in the foreground. Exactly how ice-crystals form in clouds remains under investigation".
Nota: si tratta di un'immagine molto bella, senza alcun dubbio, ma una piccola annotazione va fatta. Vedete il colore del cielo attorno al Sole? Vi sembra naturale? No, ovviamente: non è affatto naturale.
Esso è molto scuro, di colore incerto (grigio), molto simile al cielo di Marte (come si vede nei frames NASA). Ma perchè questo "strano cielo" anche sulla Terra? Diciamo che si tratta di una combinazione di fattori (su tutti il - probabile - filtro/colore usato e la circostanza per cui, scattando foto come questa e quindi sovraesponendo il Sole, automaticamente si rende più scuro tutto il resto del paesaggio).
Morale: se non si vedessero degli uccelli in transito, questa bella immagine potrebbe tranquillamente rappresentare un tramonto (o un'alba) su Marte.
La nostra deduzione è che il fatto di credere a quello che si vede in una fotografia (terrestre, marziana o lunare) e commentarlo, sta diventando sempre più una questione di "Fede" e non - purtroppo - di effettiva oggettività .
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FL-Anticrepuscolar Rays.jpgInfinite62 visiteCaption NASA originale:"(...) Pictured above are anticrepuscular rays.
To understand them, start by picturing common crepuscular rays that are seen any time that Sunlight pours though scattered clouds. Now although Sunlight indeed travels along straight lines, the projections of these lines onto the spherical sky are great circles. Therefore, the crepuscular rays from a setting (or rising) Sun will appear to re-converge on the other side of the sky.
At the anti-solar point 180° around from the Sun, they are referred to as anticrepuscular rays (...)".
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AuroraBorealis-Alaska.jpgAurora over Alaska62 visiteCaption NASA:"Higher than the highest mountain, higher than the highest airplane, lies the realm of the aurora. Aurora rarely reach below 60 Km, and can range up to 1000. Aurora light results from solar shockwave causing energetic electrons and protons to striking molecules in the Earth's atmosphere. Frequently, when viewed from space, a complete aurora will appear as a circle around one of the Earth's magnetic poles. The above digitally enhanced photograph was taken in 2005 January shows a spectacular aurora borealis above the frozen landscape of Bear Lake, Alaska, USA.
The above image was voted Wikipedia Commons Picture of the Year for 2006".
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SOL442-2N165615279EFFA978P1997R0M1-2.jpgDreaming a New Day...62 visite"...Il Sole che tramonta per alcuni, per altri è il Sole che sorge..."
(anonimo)MareKromium
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Under_The_Stars.jpgOld Faithful...62 visite
Caption NASA:"You don't have to be at Yellowstone to see a sky this beautiful, but it helps. Only at Yellowstone National Park in Wyoming, USA, would you see the picturesque foreground of the famous "Old Faithful Geyser" erupting in front an already picturesque sky. Old Faithful Geyser, visible in the foreground, is seen propelling a stream of hot water over 30 mt up in the air. This happens predictably for a few minutes about every 90 minutes. Also predictable are the brightest orbs that popular the nighttime sky, although those visible at any one time keep changing. Visible far in the background sky of this mid-June image are the plane of our Milky Way Galaxy on the left, and the bright planet Jupiter on the right. Jupiter is the brightest celestial object in the entire image. Old Faithful has been erupting at least since the late 1800s".
Nota: siamo curiosi di vedere quando la NASA "ipotizzerà " (ironizziamo, poichè le evidenze fotografiche in nostro possesso sono già innumerevoli) che alcuni fenomeni attualmente catalogati come "minicicloni" o "Dust Devils" (DD) sono, in realtà (ed in maniera particolare nelle aree presso-polari), dei geysers.
Geysers che, a volte, eruttano fango e ghiaccio e, altre volte - forse - acqua calda ed idrocarburi.
Staremo a vedere...MareKromium
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Voyagers-00.gifTowards the "Terra Incognita" (1)62 visiteInterstellar Mission - Mission Objective
The mission objective of the Voyager Interstellar Mission (VIM) is to extend the NASA exploration of the Solar System beyond the neighborhood of the outer planets to the outer limits of the Sun's sphere of influence, and possibly beyond. This extended mission is continuing to characterize the outer Solar System environment and search for the heliopause boundary, the outer limits of the Sun's magnetic field and outward flow of the solar wind. Penetration of the heliopause boundary between the solar wind and the interstellar medium will allow measurements to be made of the interstellar fields, particles and waves unaffected by the solar wind.
The VIM is an extension of the Voyager primary mission that was completed in 1989 with the close flyby of Neptune by the Voyager 2 spacecraft. Neptune was the final outer planet visited by a Voyager spacecraft. Voyager 1 completed its planned close flybys of the Jupiter and Saturn planetary systems while Voyager 2, in addition to its own close flybys of Jupiter and Saturn, completed close flybys of the remaining two gas giants, Uranus and Neptune.
At the start of the VIM, the two Voyager spacecraft had been in flight for over 12 years having been launched in August (Voyager 2) and September (Voyager 1), 1977. Voyager 1 was at a distance of approximately 40 AU (Astronomical Unit - mean distance of Earth from the Sun, 150 million kilometers) from the Sun, and Voyager 2 was at a distance of approximately 31 AU.
As of July 2007, Voyager 1 was at a distance of 15.4 Billion Kilometers (103 AU) from the sun and Voyager 2 at a distance of 12.4 Billion kilometers (83 AU).
Voyager 1 is escaping the solar system at a speed of about 3.6 AU per year, 35 degrees out of the ecliptic plane to the north, in the general direction of the Solar Apex (the direction of the Sun's motion relative to nearby stars). Voyager 2 is also escaping the solar system at a speed of about 3.3 AU per year, 48 degrees out of the ecliptic plane to the south.
Both Voyagers are headed towards the outer boundary of the solar system in search of the heliopause, the region where the Sun's influence wanes and the beginning of interstellar space can be sensed. The heliopause has never been reached by any spacecraft; the Voyagers may be the first to pass through this region, which is thought to exist somewhere from 8 to 14 billion miles from the Sun. In December 2004 Voyager 1 crossed an area known as the termination shock. This is where the million-mile-per-hour solar winds slows to about 250,000 miles per hour—the first indication that the wind is nearing the heliopause. Voyager 2 is currently observing preshock phenomena, indicating that it is close to the termination shock. The Voyagers should cross the heliopause 10 to 20 years after reaching the termination shock. The Voyagers have enough electrical power and thruster fuel to operate at least until 2020. By that time, Voyager 1 will be 12.4 billion miles (19.9 billion KM) from the Sun and Voyager 2 will be 10.5 billion miles (16.9 billion KM) away. Eventually, the Voyagers will pass other stars. In about 40,000 years, Voyager 1 will drift within 1.6 light years (9.3 trillion miles) of AC+79 3888, a star in the constellation of Ophiucius. In some 296,000 years, Voyager 2 will pass 4.3 light years (25 trillion miles) from Sirius, the brightest star in the sky . The Voyagers are destined—perhaps eternally—to wander the Milky Way. For current distances, check: Mission Weekly Reports
MareKromium
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Sunset~1.jpgUntitled (by Brian Cameron)62 visitenessun commentoMareKromium
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