| Ultimi arrivi - Artistic Views of the Solar System |
Enceladus~2.jpgEnceladian Geysers123 visiteDa "NASA - Picture of the Day" dell'8 Giugno 2006:"In this stunning Saturnian vista - one in a series of artist's visions of volcanos on alien worlds - icy geysers erupt along narrow fractures in inner moon Enceladus. The majestic plumes were actually discovered by instruments on the Cassini Spacecraft during close encounters with bright and shiny Enceladus last year. Researchers now suspect the plumes originate from near-surface pockets of liquid water with temperatures near 273 kelvins (0° Celsius) - hot when compared to the distant moon's surface temperature of 73 kelvins (- 200° C). A dramatic sign that tiny, 500km-diameter Enceladus is surprisingly active, these ice volcanos hold out another potential site in the search for water and origin of life beyond planet Earth.
Enceladus' ice volcanos also likely produce Saturn's faint but extended E-Ring". Giu 08, 2006
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Mars-1.jpgSummer afternoon...On Mars!90 visitenessun commentoMar 22, 2006
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Terminator.jpgLunar Terminator90 visitenessun commentoMar 07, 2006
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Voyagers-Heliosphere6b.JPGWhere are the "Pioneers"?92 visitePioneer 10 will continue into interstellar space, heading generally for the red star Aldebaran, which forms the eye of Taurus. Aldebaran is about 68 LY away and it will take Pioneer over 2 MY to reach it.
The Mission of Pioneer 11 has ended: the last communication from
Pioneer 11 was received in November 1995, shortly before the Earth's motion carried it out of view of the spacecraft antenna. The spacecraft is headed toward the constellation of Aquila, Northwest of the constellation of Sagittarius. Pioneer 11 will pass near one of the stars of Sagittarius in about 4 MY.
PIONEER SPACECRAFT CONDITIONS: very cold with most temperature readings at the bottom of their scale. Bus voltage about 26 volts (nominal is 28). Uplink received from DSS 14 at -131.7 dbm. Two commands received, both confirmed as executed. Geiger Tube Telescope Instrument on, and data received.
Project Phoenix has been observing Pioneer 10 at Arecibo in Puerto Rico through the auspices of the SETI Institute. The signal from Pioneer 10 was also picked up at Arecibo on 2 March 2002.
The last telemetered data from the University of Iowa cosmic ray instrument were as follows: 2 March 2002 (39 minutes of clean data) (r = 79.83 AU) 27 April 2002 (33 minutes of clean data) (r = 80.22 AU)
At GMT 17:27:30, Saturday, 4/28/01, the signal from Pioneer 10 was received at station 63 in Madrid, the first time since August 5/6 of 2000. So it appears that Pioneer 10 has life, albeit in another mode - i.e., only in a two-way coherent mode. We have been listening for the Pioneer 10 signal in a one-way downlink non-coherent transmission mode since last summer with no success. We therefore conclude that in order [for Pioneer 10] to talk to us, we need to talk to it. This means from now on, we need two-way round-trip light time (RTLT) passes to allow the Deep Space Network (DSN) to send up a strong stable signal to lock up with a coherent downlink signal.
Feb 28, 2006
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Voyagers-Heliosphere5b.JPGThe Voyagers at the "Final Frontier"88 visiteThe twin Voyager 1 and 2 spacecrafts continue exploring where nothing from Earth has flown before. In the 25th year after their 1977 launches, they each are much farther away from Earth and the Sun than Pluto is and approaching the boundary region - the heliopause - where the Sun's dominance of the environment ends and Interstellar Space begins. Voyager 1, more than twice as distant as Pluto, is farther from Earth than any other human-made object and speeding outward at more than 17 Km per second (38.000 miles per hour). Both spacecraft are still sending scientific information about their surroundings through the Deep Space Network (DSN).
The primary mission was the exploration of Jupiter and Saturn.
After making a string of discoveries there - such as active volcanoes on Jupiter's moon Io and intricacies of Saturn's rings - the mission was extended. Voyager 2 went on to explore Uranus and Neptune, and is still the only spacecraft to have visited those outer Planets. The adventurers' current mission, the Voyager Interstellar Mission (VIM), will explore the outermost edge of the Sun's domain. And beyond.
Feb 28, 2006
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UB-313.jpgUB 313: is this the "10th Planet"?76 visiteWhat do you call an outer Solar System object that is larger than Pluto? Nobody is yet sure, but the question arose recently when 2003 UB313, an object currently twice as far out as Pluto and not in the plane with the rest of the Planets, was verified recently to be 30% wider than Pluto. UB313's size was estimated (of course in a VERY approximate way!) by measuring how much infrared light this celestial body emits. Previous size estimates were based only on visible light and greatly affected by how reflective the object is.
Whether 2003 UB313 is officially declared a planet will be answered shortly by the International Astronomical Union (IAU).
In the above picture, a scientific artist has imagined UB313 in its distant orbit around the Sun, coupled with a hypothetical moon. Feb 07, 2006
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Titan-IMG001958-br500.jpgHuygens' Landing Site103 visiteThis is an artist's interpretation of the area surrounding the Huygens Landing Site, based on images and data returned on Jan. 14, 2005.
On January 14, 2005, the European Space Agency's (ESA) Huygens Probe reached the upper layer of Titan's atmosphere and landed on the surface after a parachute descent 2 hours and 28 minutes later.
As part of the joint NASA/ESA/ASI mission to Saturn and its Moons, the Huygens Probe was sent from the Cassini spacecraft to explore Titan, Saturn's largest moon. Titan's organic chemistry may be like that of the primitive Earth around 4000 MY ago, and it may hold clues about how life began on our Planet.
Nota: permetteteci un piccolo commento su questo "grande successo". Di dati significativi sull'ambiente di Titano (p.e.: temperature medie nel ciclo giorno/notte; presenza o meno di venti; presenza o meno di polveri in sospensione; componenti primari dell'atmosfera a varie altitudini etc.), ad oggi, non ci pare ne sìano emersi. A parte qualche "sembra" e qualche "si sta ancora studiando" non c'è ancora nulla di solido su cui lavorare (o almeno speculare). E questo per non dire delle fotografie di Titano al suolo: dovevano dirci tanto. Alla fine, quelle poche (ed orrende) immagini ricevute non ci hanno detto assolutamente niente.
La "Discesa dell'Europa su Titano" (come si scrisse in tono trionfalistico un anno fa - per poi dimenticare tutto in 24 ore...) fu dunque vera gloria?
Ai posteri l'ardua sentenza...
Gen 14, 2006
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Mars~0.jpgMars' Orbital Insertion148 visitenessun commentoNov 04, 2005
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WW31.jpg1998-WW3187 visiteThis is an artist's view of a Kuiper Belt binary object, called 1998 WW31. These icy bodies orbit each other at the fringe of our Solar System.
The illustration depicts one member of the duo in the foreground; its companion - the dark, round object - is in the background. The objects are about the same size. Both are illuminated from behind by the Sun [the white dot at upper left]. Like other Kuiper Belt objects, this duo orbits the Sun, completing a circuit every 301 years while Pluto orbits the Sun every 248 years.Nov 03, 2005
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Asbolus.jpg8405 Asbolus135 visiteThis is an artist's impression of object called 8405 Asbolus: a 48-mile-wide (about 80 Km) chunk of ice and dust that lies between Saturn and Uranus. Astronomers using NASA's HST were surprised to find that one side of the object (also called a "Centaur") looks like it has a fresh crater less than 10 MY old, exposing bright underlying ice. Actually, Hubble didn't directly see the Crater - the object is too small and far away - but a measure of its Surface Composition shows a complex chemistry that could be explained by the presence of a huge Impact Crater. The event that caused the Impact Crater on 8405 Asbolus may be the same one that knocked it out of the Kuiper's Belt (which is a "Ring of Comet Nuclei" located just beyond Pluto's orbit).Nov 03, 2005
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Kuiper_s Belt.jpgRelationship of the Kuiper's Belt to the Oort's Cloud89 visiteThis illustration shows that the Kuiper Belt is shaped like a disk (see inset diagram) and resides within the shell-like structure of the Oort Cloud. Located on the outskirts of the Solar System, the Kuiper Belt is a "junkyard" of countless icy bodies left over from the Solar System's formation. The Oort Cloud is a vast shell of billions of comets.
The inset diagram compares Pluto's orbit with a Kuiper Belt binary object called 1998 WW31. The Kuiper Belt [the fuzzy disk] extends from inside Pluto's orbit to the edge of the Solar System.Nov 03, 2005
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Quaoar.jpgQuaoar125 visitenessun commentoNov 03, 2005
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